But now we have the Blonds shutting Max out. Actually closing their blinds, because one evening one of them saw him looking at them. When they yvere naked, of course, or half naked, which is even more tantalizing. They induced Cheap sex! Come celebrate the first annual Bay Guardian Sex Issue at a smashing, lust- filled party featuring a nasty erotic performance cabaret.
Meet the winners of our erotic fiction and limerick contests and hear them read their work. There will be spoken word performances by local luminaries Carol Queen, Cara Bruce, m. There is something ungenerous, not to say prissy, about this kind of behavior. But he did nothing more than look out the windows of his own living room.
This is American entrepreneurial mania carried to a bizarre extreme. Which is not to say the Blonds are completely inert. Max believes that every Friday or Saturday night they go to sex parties, or perhaps to the Power Exchange, - one of the few sex clubs that welcomes heterosexuals. Coupled heterosexuals, no less, though they have to pay lots more, as is only just. It is a titillating thought, almost enough to send one out in pursuit of them.
But doing so would involve a voyage into that realm where desire becomes organized and institutionalized, subject to the sway of commercial civilization and all its mad, rational calculations. But I wonder. Desire is, like most dreams, about escaping from civilization or subverting, if just for a little while, its conventions and constraints.
Only when we are dreaming or fucking are we ever really free. That is why sexual institutions are so stultifying. At least Max thinks so. But from his vantage point behind those blinds he sees no evidence of one — not yet. Friendly, 24 Hour Customer Service San Francisco No connection fee.
Win a trip for 2 to France! This assumes, of course, that people know why they want sex, which is a generous assumption indeed. Do we really need to talk about anything more serious than where the latex barriers are? Lots of people claim to want nonromantic sex, but end up creepily fixated on the people who fuck them.
The problem here is that sex is so rarely discussed as such. Confusing sex with other things has lead to our current abysmal state, in which most of us are bad at sex and bad at being romantic. Perhaps because sex has taken on so many meanings, the physical act itself has become a kind of sinister unknown.
People deal with their confusion about sex in numerous ways, but most of us can be divided into two coping- mechanism camps. And thus, although people talk about romance ad nauseam, they shun it. So basically we rarely talk about sex, although we have it; and we rarely fall in love, although we talk about it a lot.
They would make the mistake of always falling in love with their sexual partners, and the inevitable rejections were incredibly painful for them. The truth is that sex and love do go together, but not necessarily, and this is the kind of messy equation we all hate because it requires us to think.
Winner "Best of the Bay" Over local photo-ads! Get It Here First! Available in early June only at www. Pre-order your copy today! Roche and other writers organize readings to support the local erotica scene. These happen in art spaces, theaters, and independent bookstores. He sees a parallel with the punk rock scene, which also appreciates radical self-expression. And this may be more true for visual arts than for writing. Others trace it back to the Barbary Coast days. Meanwhile, the presence of such a throbbing, pulsating, convulsing erotica writing scene in San Francisco has drawn many multifaceted writers to focus on erotica.
Roche writes horror and crime fiction but prefers to read erotica. Christian, the author of Dirty Words and the editor of many anthologies. While you're changing TV channels our students are changing their lives. Previously you had to travel all the way to Miami for this program. Miami Ad School has opened in San Francisco. And get this. When you intern the agency gives you a tuition scholarship and provides housing. Most students have produced TV commercials, print ads, radio spots or web sites.
Our students graduate with a great portfolio and practical experience. Registration for next quarter ends June 2. Still time to change your brain. As you trek through the Zoo, you'll encounter African elephants, gorillas, snow leopards and all sorts of interesting animals.
There'll be a chance to win some amazing prizes, including the Grand prize - a private San Francisco Zoo safari for the winner and five friends! Are you ready to play? San Francisco and the Bay Area are home to a plethora of sex-positive instructors, like myself, whose brains are bursting with sexual health knowledge that we love to share. In spite of the conservative agenda of the new Republican administration hiss Our sexuality is biological, psychological, sociocultural, spiritual, and continually evolving.
Workshop and class descriptions, schedules, and fees are usually posted on the Web sites. Fees vary from class to class. During their after-hours classes, enjoy an evening of silent stag films, learn better sexual social skills, or study foot massage. The leather corsets are magnificent I own two! Classes cover topics such as rope bondage, effective topping, and safe flogging techniques. If you would like to preregister for a class or have questions, call the Howard Street location.
Leather fanatics are in heaven here. Recently, Mr. You must be 18 or over to attend. In the evenings the warehouse turns into a classroom. Attendees must be at least 21; bring an ID if you look younger. For location and other information call or , Mon. Are you passionate or curious about BDSM but not sure who to talk to?
It is devoted to the art of safe, consensual, and nonexploitative power exchange. Attend an orientation to decide if you would like to become a member of SOJ. You must be at least Box , San Francisco, CA , e-mail janus soj. A healthy, dynamic sex life benefits from an abundance of sexual fantasies. This East Bay organization creates a comfortable, judgment-free space for clients to explore adult fetish and fantasy play.
The sessions are by appointment only and open to all sexes and orientations. Call for appointments and location. Workshops, classes, and retreats are both coed and women- only. Call for more details. San Francisco Sex Information is a free information and referral service providing anonymous, nonjudgmental information about sex.
Volunteers staff the hot line after extensive training in all aspects of human sexuality, ranging from reproduction and birth control to safer sex practices to HIV to issues about sexual and gender identity. Do you want to explore and develop your sexual potential as a woman? Would you love to destroy the myth that women cannot be both intelligent and sexual beings? Join the revolution at Vulva University and empower yourself.
Register for free classes and exchange ideas with your peers on various topics dealing with lesbian sex, ob-gyn issues, masturbation, the G-spot, etc. Leading sex educators teach the classes, which are open to everyone. Peruse the fall DE-Cal schedule of classes for times and locations. A master of arts. On the cutting edge of graduate schools specializing in sexology the study of sex is the Institute for Advanced Study of Human Sexuality.
This privately funded postsecondary school is situated right here in San Francisco. Offer expires An Equal Opportunity Club. S an Francisco 4 1 5. Come celebrate the first-annual San Francisco Bay Guardian Sex Issue at a smashing, lust-filled party, featuring a nasty erotic performance cabaret.
Meet the winners of our erotic fiction and limerick contests and hear them read their work! Find out why San Francisco s erotic art scene is worshipped the world over -- there will be spoken word performances by local luminaries Carol Queen, Cara Bruce, m. Friday, May 25 th 8 p. By Andreo Nemerson o — who wants a penis? Of course not. The participants, of various ages and sexual orientations, were all contentedly female and planning to stay that way.
They already had plenty of the sort of dick you can run through the dishwasher before tucking it away neatly in the nightstand drawer. They wanted to get a hard-on, penetrate a partner skin-to-skin, go piss against a tree, and then And why not? The whole idea probably found its finest expression on FuckU- FuckMe, the years-old Web site that unlike, say, Digital Sexations is supposed to be funny. This body is an alternative for large breast lovers who do not wish to go with the heavier body 3.
Body 5 weighs in at just lbs, and has 34 E-cup breasts! But do you really want the mechanical pup rooting around down there? And yet. Despite the less than stellar performances of the more gimmicky high-tech sex aids, the questions I get as a columnist and educator imply a faith in technology that borders on entitlement Penises should be enlargeable.
Erections should appear when summoned and stick around until dismissed. Orgasms should be not just achievable but multiple. Where can I get it? What does it cost? Is there a discount for cash? Why, from medical technology, of course, because it really is delivering the goods. More recent, less well-known products such as the prescription dit pump are similarly primitive, but who cares?
They work. Suddenly our view of sex as something too ephemeral, too personal, perhaps too mystical to understand is gone forever. If our organs are basically machines, and one breaks, we can fix it Easy! Each recent advance may be rather small, but the cumulative change has been enormous. Even the field of human anatomy, which sounds so 16th century, has seen major advances in the last 15 years or so. Sex-research cover girls Laura and Jennifer Berman therapist and urologist, respectively , posed last year for the New York Times with their weird rig full of little pieces of rabbit vagina.
Tve got at least one friend who cannot wait to have her own little buzz box implanted. New Patients Only. By the Bay Guardian staff for their tastes. Oops, sorry. We forgot we were supposed to be sexy here! Margaret rocks our world. Marcus Durant When Marcus Durant, the lead singer of Zen Guerrilla, points his finger into the crowd, it could be at anyone or everyone. Perhaps gangly, even pasty might apply. But what a snake charmer. Shawn Estes What is it about baseball players?
Their buns of steel? Sleek forearms? Well, not just. Is there anything sexier than some big, strong, young, jock-type guy you know being in fact highly sensitive, even delicate? Going home and weeping because he walked in the winning run? Who could not want to hug this person?
And then slam him? Batter up! Jack Hirschmann. He is also artistic director for layout, as well as for fashion shoots, for which he is often the model. He is intelligent, draws to- Continued on page 37 argaret cho A fter much unscientific and lustful soul-searching, we bring you an annotated list of 10 of the most desirable people in the San Francisco Bay Area.
We chose these 10 because they are hot as hell, and also because they are practically archetypes of the kinds of foxy people you meet everyday in the city and greater Bay Area What makes these people sexy? Alas, there is no orchard of ripening sweethearts in which you might wait with open arms for the next one to drop off the tree.
The rest of us who would like to have a Sweetie have got to get out and about and stay alert for possibilities Yes, some people do seem born charmers, just as there appear to be natural athletes. Still, a person can learn how to be friendly or at least appear so , make casual conversation, move a budding friendship along to the desired state, and negotiate a relationship. Long years of professional experience has taught me that for some, all of these interactions are bewildering and fraught with danger, while for others, they present an exciting challenge - like bridges to bungee jumpers.
Remember, attaining ease with people is a process, not an innate gift. Start with something familiar and comfortable - an invitation to a co-worker to share lunch - rather than approaching an attractive stranger in public, which appears to be some sort of benchmark for the shy. If you are on a Sweetie Search, the least you can do is enjoy the process. How I wish someone had steered me to that realization sooner!
It takes a lot of concentration and practice and I can still be stopped in my tracks by a direct question. The trick is moving continually to the other person instead of focusing on your own thoughts and experiences. The moral of my story: If you are still searching, keep at it. You never know when or how luck will find you.
It was more like fortune. It took my initiative asking the first woman to dance plus a little genuine luck meeting my girlfriend through her just by chance. Finally the odds caught up with me. Aneu combines the expertise of a board certified dermatologist, plastic surgeon and licensed aesthetician with the ease and accessibility of a walk-in clinical boutique that meets all of your skin care needs.
Call for your free laser hair removal consultation. Everyone is putting in a hard day at the office to prove once and for all that work should be as much fun as play! Pine So he quit taking T, got knocked up, and now he and Patrick have an insanely cute little toddler. Daddies are so sexy!
Marsha Rosenbaum There are many things that can make a person sexy. And while Dr. The CSC is a nonprofit that will house a sexuality- focused, public-access reference library, art shows and archives, a performance space, and more. Matt Rice With his infectious smile and naughty-little-boy sense of humor, Matt Rice would catch the roving eyes of almost any boy or girl lucky enough to meet him. Honore represents a nexus for many different scenes yet is truly creating something of his own through Free's parties, art installations, and the other amazing things they have in the works.
This is a list for hard-core hackers whose lives are Unbeatable Prices! Service, Quality and Selection - with over 26 years in business Act Now! Francisco off the Shops only at snooty designer eyewear stores. Shops every chance she gets. Closeouts, overstocks, discontinued styles from today's top designers. A fraction of the price. By Charles Anders oys. And representational art is passe in the land of vibrators too. According to Maria at Blowfish www.
It runs on watch batteries and comes with a snug carrying pouch. Not surprisingly. Good Vibrations Valencia, S. The superpowerful Wand is a classic, with a tennis-ball head and a two-foot stalk. The other top seller at Mr. This is a rigid cage that imprisons your penis and prevents it from achieving an erection. The Mr. As a plus, the CB is made of plastic, not metal, as are many other male chastity belts —- you definitely do not want to walk through airport security wearing a metal cage.
And it comes in hot pink and smoke gray. Does clothing count as a toy? It comes in leather or nylon, and you can adjust it to fit different body sizes or dildos, says Good Vibes toy buyer Joyce. Call us at for more information. Hence all of our frames are warranted for as long as you own the sofa. Having our choice of buying from any upholstery manufacturer in the country, we have selected seven companies who we judge to make the best styles for our San Francisco customers at the best values.
We keep in stock the frame- fabric combinations that are the most popular among San Franciscans, and the remainder are available through special order. Stop by to discuss your needs with our factory-trained non-commissioned specialists in a no-pressure hassle-free environment. Sofa so good? PAA Create your own look with our special-order program of over 15, fabric-frame combinations —and still enjoy discount pricing!
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Four colors, one price. NAU Deco-inspired sofa with blonde wedge legs. The guy at the counter pulled out some choice noses and ears from the glass cabinets, and laid them out gracelessly before me. Noses come in four colors. He pointed me to the dressing rooms. He considered himself in the mirror, as if to see if, under his skin, he had what it took to be a rabbit.
He glanced over at me as I parted the curtain to a dressing room and entered. Once inside 1 began changing. Get- ' ting naked is not half so appealing to me as changing clothes. Either way, it makes me want to open my backside and expose my front. Halfway out of my street clothes, I felt the curtain swish behind me. We got to business straightaway. Groping and pressing and kissing and ' rubbing and wrapping ourselves around each other, we worked ourselves into a short sweat.
He turned me around and, now fully the bunny, started humping me accordingly. The silken feel of my costume made the pressure from his body smooth against my skin. My faced jammed against the mirror, 1 caught a vision that made me laugh, his rabbit head heaving with excitement against my multicolored wig.
Soon we were mating in full animal fashion. We transformed back into our sely. Dirty Limerick. First Prize There once was a ram in a zoo who never had time to be blue. While some rams got mad, and others were bad, His secret, he sard, was Fuck Ewe! May is National Masturbation Month, so make masturbation your destination with a visit to Good Vibrations! Are there any ass- or anal-fetish clubs or newspapers or magazines with personal ads, or can you recommend any Internet sites for those like myself, who are dedicated to the derriere?
A: III trying to come lip with some answers for you, I either got lost in a maze of online pornography featuring teenybopper tushies or dry book lists oj proctological practice, but I couldn't find an end source groan for fanny fanciers dealing with the history or sociology thereof Readers? Q: I am in a relationship with someone whom I love very much.
We are not married, mainly because I believe he fears it, and I do not press the issue because I feel as though I am a special person who should not need to ask someone to marry me. We have various problems that we want to work out before getting married. One of those problems is the fact that he is, and always has been, more liberal with sex than I am. He has, as I perceive it, a rather shady past, and it bothers me immensely.
I understand that his past is his and none of my business. I know this problem is hurting our relationship. He is a good person. I know this. He is a great father. He is close with his family, etc. I have been to three psychologists already for these and other issues.
How can I keep his past from haunting me? How can I try to make our relationship better? I want to love him fully, for who he is, and not worry about the things he did 10 years ago or think about the mind-set he had when he was We are 30 years old. I always thought the person I would be with would share my views on sex, but I love him, and I have to learn to accept his liberalism. Find a local mental-health clime or therapist or counseling service with a sliding scale and go learn some practical tips on self-talk what to say to yourself instead of running those old, tired tales about your partner's past.
You can't afford not to get good psychological help. Does soul kissing with saliva male-to-male or female-to-female constitute an exchange of body fluids? A: It does from anyone to anyone, but saliva is not considered a risky behavior for FUV transmission. Kiss whomever yeti please. You can reach her online at her Sexuality Forum www. You can also write to her care of the Bay Guardian, Hampshire, S.
Alas, she cannot answer questions individually. L ots of people on Slashdot and practically nowhere else were talking about the weird and tragic suicide of a year-old hacker in New jersey. According to the Times, a Trenton, N. Regardless, Shinjan was shaken up enough that he decided death was his only option. Was this hacker honor? Death before discovery? Maybe he was part of an international ring of conspirators who were launching denial-of- service attacks.
Or maybe you become a radical subversive with a very big brain. Either way, you get smarter and probably more sarcastic, both of which are socially productive results in my book. Shinjan was a nice kid. He was known best for his archetypally geeky, overachieving activities, like playing violin in the school band, swimming, and learning new computer languages in his spare time.
And it would be nice if we could simply blame his principal, who suspended him, or his parents, or some other antihacking authority figure. But the fact is, Shinjan probably just became suicidal for the same reasons thousands of other teenagers do. He was different, and he got fingered for being different. Seems like nonconformists are dying left and right. If school doesn't kill them, the corporate world will.
That reminds me of what happened to dear, recently departed Douglas Adams geek-hero author of several Doctor Who episodes and the Hitchhiker's Gnitle to the Galaxy series , whose last gasps were spent giving a keynote speech at some stupid conference on mobile computing in San Francisco. For the same reason Shinjan hung himself.
So long, Douglas and Shinjan, and thanks for all the fish. Her column also appears in Metro, Silicon Valley's weekly newspaper. SunTrips www. No advance purchase required. Ttavel Smart with H. Please ask our agents lor other restrictions. Taxes not included. Fares are subject to change. CST www. OcL For more info: www. Now W. Of course, the rough setting just makes being inside the restaurant that much more pleasant.
Like many California menus, hers meanders cheerfully across cultures and cuisines: you could open with anything from shrimp-and-green-bean tempura to a warm brie baguette. Cajun-fried 51 The Blender 53 The Groaning Board The high life: Buzz 9 co-owner Tanya Pampalone and chef Celestine Pasquier proudly display baked goat-cheese salad with Granny Smith apples and candied walnuts, one of many inventive dishes on the menu.
News of Noi in Noe calamari with a very sassy remoulade. There is a filet mignon dish on the menu, but the bulk of the choices are chicken, fish, and pasta — welcome in any case, but particularly to those of us who see latter-day American culture mainly as one of excess. People were not meant to live amid such bloating abundance. But enough about lightness and the dull virtue of calorie counting.
Sooner or later carnivorousness will out, and when that moment arrives. Buzz 9 Cafe. Breakfast: Mon. American Express, MasterCard, Visa. Can get noisy. Wheelchair accessible. Given that heritage, and the fact that noi means we in Italian, it will probably not surprise anyone that the new restaurant will be dealing in Italian food. Twenty years ago the youthful Little Italy was one of the few places in Noe Valley where you could get genuinely good food; the rest of the neighborhood's restaurant scene lay aslumber.
I also detected healthy crowds earlier this year at Valentine's, the vegetarian cafe on Church at 30th, in outer Noe Valley. The restaurant, in its sixth year, seemed to be running smoothly: good food, skillful service, reasonable prices. But after Memorial Day the plan is to open up for dinner as well, from Wednesday through Sunday evenings.
Let there be flavor! Paul Reidinger paulr sfbg. Closed Mondays Till j Sun. Folsom Who I was with was my boyfriend Binko. Ideal, you might say, considering the general aloofness of most pelicans. I owed him because the next day 1 was hungry again, believe it or not, and I showed up at his door uninvited just like some pathetic kid out of Dickens, or bluegrass music.
And Binko, bless his Bink Which I stretched into two weeks by always eating it over hot dogs. So if you heard some strange sirenlike and not entirely unmelodic noises emanating from the vicinity of Dog Shit Park this past week or two As for the smell Crawdad can take it. No bones in any of the many kinds of rolls and nigiris we tried, just to name one little difference.
And it was good. Do you realize what that means? That means you can have ten pieces of saba for under ten bucks! I tried some other stuff, including some of the crazy rolls Binko ordered, on the off chance that I might maybe have a little something to say about something.
We sat at a table, one of a handful of them up front with a big window out onto Church Street and a big badass biker dude, cigarette dangling, who almost parked his big badass bike right through the big window, which would almost certainly have changed the atmosphere some. As it was, though, the handlebar just bounced loudly off the glass, and everyone looked up, laughed or sighed, and sunk back into their chili rolls and raw hot dogs over rice.
Lunch: daily, a. Takeout available. You can find short stories by Leone each week in Looseleaf, on sfbg. COM Woke up free! Take Out Too! Open for dinner Tues - Sun from p. Mountain View Let Philadelphia have its cheese steaks, Maryland its crab cakes. Others may roam the back roads searching out the juiciest burger or best barbecue sandwich.
Compared with a lobster roll, all these much-disputed sources of civic pride are just so much meat on a bun. The lunch crowd had departed, and the dinner rush was still a couple of hours away, so I could sit right down at one of the 9 or 10 stools up against the marble counter.
Next to me, a man was methodically working his way through a dozen bluepoints, while at the single corner table a couple with a baby were dawdling over bowls of creamy, sea-scented dam chowder. You get a lobster roll out on a pier somewhere: the waves slapping against the boats, seagulls sitting on old white-painted railings, hustling for stepped-on french fries, and the half-tingly, half-itchy sunburned backs of your legs scraping against the splintery, weathered gray wood of the benches ranged up against the dozen picnic tables overlooking the water.
There are onion rings, maybe corn on the cob or hot dogs, iced tea and lemonade in beaded, waxy cups. The roll squelches when you bite it, and pieces of lobster threaten to tumble to the slightly grubby, checked vinyl tablecloth above your lap. It is rich but rustic, practically as easy to put together as a tuna sandwich but infinitely more sublime.
So we drove from one creaking See You Next June! Lobster boats bobbed in the ripples of the silvery blue water, stateLy pine trees ridged the islands scattered in the bay, and a big Closed for the Season sign was draped across the red bam of the Five Islands Lobster Company, where. Oh well. All area codes are and all restaurants are wheelchair accessible, except where noted. The mainly Italian menu, though inexpensive, shows some real styling, and the atmospherics are simple but powerful.
The touch of human hands is everywhere evident. Recently reviewed Punahele Island Grill will remind you of one of those plate-lunch spots on the Big Island. You get lots of food for not much money, in a casual, almost familial, setting. The only giveaway is the weather. Ramblas resists the globalized-tapa trend by serving up Spanish classics. And they are good, from grilled black sausage to cala- mares a la plancha to crisp potato cubes bathed in a vivid red-pepper sauce.
The subterranean dining rooms are spacious, gracious, and muted; the high-end Chinese menu is a marvel of freshness, and priciness. On the cheap: spicy! Pakwan has a little secret: a secluded garden out back. The platters are so full of Eritrean food as to have a kind of topography. Moderate prices; vegetarian friendly; a welcome refuge from yuppie blight. Thai Time proves that good things come in little packages. The place is tiny, and the food is tremendous, especially the hor mok talay, a seafood medley in coconut red-curry sauce cooked in a coconut shell.
Even more familiar Thai standards are rendered with force and verve. The food marches from the kitchen like a well-trained brass band; the flavors are big and direct, to match all those California wines. Staff California at Battery , S. Tu Lan has few luxuries except the food, which is a luxury to the wealthiest palate.
Staff 8 Sixth St. North Beach, Chinatown Black Cat has been reborn as a kind of French bistro, consecrated to the beat poets. The full bar and extensive menu of tapas, pizzas, pastas, and grills make dropping in at any hour a real treat. House of Nanking never fails to garner raves from restaurant reviewers and Bay Guardian readers alike.
Chinatown ambience, great food, good prices. Best Ofs, Kearny at Columbus , S. Zax belongs to the group of top-flight mid- s neighborhood restaurants that were and are the best places to eat California cuisine. From a goat-cheese souffle with apple-fennel slaw to braised lamb shank with pancetta-scented white beans, the food — fresh, precise, imaginative but not too — is the star.
But the hot sauce will make you sneeze. Many dishes acquire a heart-swelling smokiness from the oven — a plate of por- tobello mushrooms, say, with soft polenta and mascarpone butter. Sushi Groove South continues the westward march of hipsterdom through SoMa. Nob Hill, Russian Hill Crustacean is famous.
Le Jardin feels a bit like a second-story beer hall, but the chef is a Slanted Door alumnus, and his Vietnamese food shows promising glints of that experience. The dining room can be a bit drafty but does afford good views of the still-seedy Polk Street scene. The sushi is first rate, but the great stuff on the menu is cooked: buttery-tender beef short ribs and a seafood-miso soup served in a teapot.
Service is friendly and swift, prices low, and you can get dal with practically everything. OneAsia brings some pan-Asian glow to the northeast Civic Center. Lots of good soups, noodle dishes, and Asian rolls; fancier dishes are a bit chancier. The three-course lunch deal is one of the best ones going. More than 30 different kinds of premium sake are available! Garage entrance on O'Farrell Street For complete menu, delivery and catering info see www.
Pachl Cahio v Perez. COM www. An old, reliable friend. Zuni The old standbys are reliable, though the famous burger could do with a bit less focaccia, and the oddly greasy Caesar salad is far from the best in town. The best dishes are Italian in their simplicity and pureness. The more complex dishes, such as a tuna-sashimi tartare with lemon olive oil, are better than the simple, traditional stuff, which can be overchilled. Fine service, moderate prices.
Cafe J keeps a low decorative profile, but the Basque dishes really rock. The second-floor space brings a welcome serenity. Zodiac Club numbers quite a few local chefs among its patrons, and that ought to tell you something about the quality of the eastern Mediterranean-influenced food. Lots of lamb, imaginatively handled, in a way-cool atmosphere of ultraviolet light.
Another plus: not much price inflation. Haight, Cole Valley, Western Addition Asqew Grill reinvents the world of fine fast food on a budget with skewers, served in under 10 minutes for under 10 bucks. Eos serves one of the best fusion menus in town, but be prepared for scads of yuppies and lots of noise. Ganges spices its savory vegetarian Indian fare with a very liberal hand. The menu changes often to take advantage of seasonal vegetables and the creativity of the chef.
Staff Frederick at Willard , S. Go belbre 9 p. A singular experience. Staff Valencia at 19th St. Cafe Arguello soothes jangled urban nerves with an airy space, votive candles, louvered bistro tables, a subtly impressionist paint scheme — and moderately priced Spanish food, from tapas to blockbuster paellas.
The place to go when you want to indulge your spontaneity muse. Fill up with a thick milkshake on the side, but skip the disappointing fries. Staff Mission at Silver , S. Mi Undo Peru dishes up mom-style cooking, Peruvian style, in illimitable portions. The shrimp chowder is astounding.
Lots of tapas, too. Staff Cortland at Gates , S. Potrero Brewing Co. Taqueria Can-Cun serves up one of the best veggie burritos in town — delicious, juicy, and huge. Staff Mission at 19th St. Ti Couz The menu of entries here consists exclusively of crepes — from light snacks to full meals, from sweet to savory — served up in a bright, boisterous cafr environment. Staff 16th St. Tokyo Go Go The simplest dishes are the best.
Given the location and the thick crowds of people dressed in black, the noise level is surprisingly moderate. La Villa Poppi feels like a Tuscan country inn. Restaurant YoYo joins the food maelstrom at Valencia and 16th Streets bearing a powerful tool: sushi, good and cheap.
Chocolate-chunk cheesecake, Just Desserts 2. Baked rigatoni with jerk turkey and refried beans 4. Montage, or the Federation starship Enterprise? B Spot invites relaxation, from the ceiling fans to the reassuring pub food to the fine smooth beer. But come dinnertime the Mexican brunch influences melt into a sublime French sauce- fest. Prices are modest, the service swift and professional. Eastside West fits right into the Cow Hollow scene. Mezes glows with sunny Greek hospitality, and the plates coming off the grill — pork souvlaki, marinated prawns — are terrific, though not huge.
Bulk up with a fine Greek salad. Sunset Blue Tortilla If you like fish tacos and are having trouble finding them, this could be the place. The cantina surroundings have a lively L. If in doubt, stick to pasta over roast chicken. Just got better. TNN S. Cafe for All Seasons reflects the friendly vi- brance of its West Portal neighborhood.
Everyone is welcome, from grandparents to small children to big fuzzy bears on a date. The perfect place to go with your parents. E The kitchen turns out such unusual dishes as a fresh corn-cakes appetizer and curried fish mousse wrapped in banana leaves. Staff Irving at 23rd Ave. Staff Irving at Ninth Ave. Desserts emphasize boozy sauces. Excellent sushi with sly touches — a sprig of mint in a spider roll, say.
A good soundtrack, too. Worth discovering. Prices are moderate, service informal but attentive, the setting attractive in a well kept-up s style. Two fine dishes: veal scallops, Milanese style, and the criminally rich brownie. Go for the free valet parking. Natori fulfills the dreams of those who crave sushi but can never get enough. Plenty of other Asian dishes are on offer, from kim- chee to pork-fried rice. Okina Sushi is resolutely discreet and old- fashioned, from the bamboo screens on the windows to the simple wood bar at the back.
Japanese, D, c. Straits Cafe has a slightly campy faux- tropical decor, but its Singaporean menu is a kaleidoscope of mingled satisfactions. Outback Cafe is located way down in with all them warehouses at the end of Revere Street. I found the fare delectable. I got a double cheeseburger and a cup of soup. This is gourmet stuff. At least of them are under five bucks. For the heat-seeking diner, its fiery Szechuan specialties will hit the spot. Nice chow fun and other noodle dishes, too.
Staff Bayview Plaza, Third St. Only four of those are more than five bucks. Cafe La Pena nurtures the spirit as much as it pleases the palate. Excellent sandwiches, inventive salads, and simple pasta dishes highlight the lunch menu. Cha-Ya Everything chef-proprietor Atsushi Katsumata makes, from the potstickers and nigiri sushi to the steaming bowls of udon, hews to strict vegan standards.
Almost every unusual combination works, with generous helpings smoothly delivered in beautiful presentations. Clay Pot Seafood House specialties include steaming clay pots full of fascinating broths and such ingredients as meat balls, Chinese sausage, and whole fish.
Bayou serves up an astounding array of authentic New Orleans staples, including jambalaya, red beans and rice, sausage or oyster po-boys, greaseless! Fixed-price dinners are available week- nights along with an k la carte menu that changes monthly. Voulez-Vous distinguishes itself with its airy Parisian-cafe setting and a diverse array of beautifully presented crepes and tarts.
Not wheelchair accessible. Staff Clay at 10th St. Giglio combines a lively yet intimate cafe atmosphere with moderately priced thin- crust pizzas and wines, hearty pastas, and soups. Kandahar Chef-owner Daud Zaheer invests his Afghan lamb, chicken, and vegetarian dishes with big-time love and attention and presents them beautifully at bargain prices.
Our year-old recipes are prepared fresh every day. Or how about something a biL more modem. Like our luscious Tandoori barbe cues, freshly prepared in a clay oven imported all the way from India. Served with a wide selection of fine wines. The Presidio May Bat Makumba at the Justice League 3. Badly Drawn Boy disaster at the Fillmore 4. Impromptu high school reunions 5. Yankee Dawg You Die! Where the sidewalk ends: Ed Ruscha turns the city into a dreamscape in works like Street Meets Avenue I grew up in the s in San Fernando Valley, a flat, horizontal expanse of L.
I never escaped its visual imprint. After the inimitably vibrant glow of a smoggy sunset, the glittering lights of Hollywood glowed on the other side of the mountains. But 1 see similar things when I go to New York. I see a lot of real vital im-. A, particularly, it happens to be that I live there.
I like the idea of listening to the music and looking at this still scene out here. It kicks off something. Maybe a classical piano piece is overlapping with a country-and-west- ern tune. Sometimes a voice comes in, a news report or something. I like listening to stuff like that. It makes sense then that he approaches his work with instinct and a bit of restlessness. All RJghls Reserved. By Johnny Ray Huston Altered states: Under the Sand examines the grieving process of a woman Charlotte Rampling faced with the disappearance of her husband.
F rancois Ozon apparently has a thing for a woman in a sundress at the beach. As Marie reads a book, Jean ventures into the ocean for a swim. Appendix B. Proposed and ongoing synthetic fuel production projects. RCG , has developed a procedure for matching prospective users and producers of synthetic fuel.
The matching procedure, which involves a hierarchical screening process, is designed to assist OFC in: locating a supplier for a firm that wishes to obtain a synthetic fuel exemption; determining whether the fuel supplier proposed by a petitioner is technically and economically capable of meeting the petitioner's needs; and assisting the Synthetic Fuels Corporation or a synthetic fuel supplier in evaluating potential markets for synthetic fuel production.
A data base is provided in this appendix on proposed and ongoing synthetic fuel production projects to be used in applying the screening procedure. The data base encompasses a total of projects in the seven production technologies. Gas-to-liquids synthetic fuels for use in fuel cells : reformability, energy density, and infrastructure compatibility.
The fuel cell has many potential applications, from power sources for electric hybrid vehicles to small power plants for commercial buildings. The choice of fuel will be critical to the pace of its commercialization.
This paper reviews the various liquid fuels being considered as an alternative to direct hydrogen gas for the fuel cell application, presents calculations of the hydrogen and carbon dioxide yields from autothermal reforming of candidate liquid fuels , and reports the product gas composition measured from the autothermal reforming of a synthetic fuel in a micro-reactor.
The hydrogen yield for a synthetic paraffin fuel produced by a cobalt-based Fischer-Tropsch process was found to be similar to that of retail gasoline. The advantages of the synthetic fuel are that it contains no contaminants that would poison the fuel cell catalyst, is relatively benign to the environment, and could be transported in the existing fuel distribution system. The feasibility of synthetic fuels in renewable energy systems. The purpose of this article is to identify potential pathways for producing synthetic fuels The purpose of this article is to identify potential pathways for producing synthetic Full Text Available The article notes a stable tendency to increasing the oil dependence of Ukraine, which creates a threat to the national economic security, and proves an expediency of establishing domestic production of synthetic liquid fuel.
The technical, organizational and economic features of establishing synthetic liquid fuel production in Ukraine are presented. There proved a hypothesis on the expediency of organizing the production of synthetic liquid fuels based on steam-plasma coal gasification technology. The forecast resource cycle of the country until under conditions of developing this technology is modeled. Synthetic carbonaceous fuel and feedstock using nuclear power, air, and water. An absorption-stripping system utilizing dilute carbonate solvent appears most economical for atmospheric recovery while distillation appears of interest for sea-water recovery.
An alternative isothermal process utilizing chlor-alkali cells is also described. Production cost is dominated by the energy for hydrogen and the plant capital investment. Base loaded nuclear power plants supplying peaking load and generating SCFF in an off-peak mode is proposed for reducing costs. Method of producing nuclear fuels. Purpose: To fabricate a nuclear fuel assembly with uniform enrichment degree, in the blanket of a hybrid reactor.
Then, plasmas are formed in the inner space of the blanket so as to enrich the source materials by the irradiation of neutrons. After the average degree of enrichment reaches a predetermined level, the material vessel is discharged by the conveying gas onto a conveyor.
The powder materials are separated from the source-material vessel and then charged into a source-material hopper. The mixed material of a uniform enrichment degree is supplied to a fuel -assembly-fabrication device. FP gases resulted after the enrichment are effectively separated and removed through an FP gas pipe.
Horiuchi, T. Segmental intelligibility of synthetic speech produced by rule. This paper reports the results of an investigation that employed the modified rhyme test MRT to measure the segmental intelligibility of synthetic speech generated automatically by rule. Synthetic speech produced by ten text-to-speech systems was studied and compared to natural speech.
A variation of the standard MRT was also used to study the effects of response set size on perceptual confusions. Results indicated that the segmental intelligibility scores formed a continuum. Several systems displayed very high levels of performance that were close to or equal to scores obtained with natural speech; other systems displayed substantially worse performance compared to natural speech.
The overall performance of the best system, DECtalk--Paul, was equivalent to the data obtained with natural speech for consonants in syllable-initial position. The findings from this study are discussed in terms of the use of a set of standardized procedures for measuring intelligibility of synthetic speech under controlled laboratory conditions.
Recent work investigating the perception of synthetic speech under more severe conditions in which greater demands are made on the listener's processing resources is also considered. The wide range of intelligibility scores obtained in the present study demonstrates important differences in perception and suggests that not all synthetic speech is perceptually equivalent to the listener. The overall performance of the best system, DECtalk—Paul, was equivalent to the data obtained with natural speech for consonants in syllable-initial position.
Synthetic and Biomass Alternate Fueling in Aviation. While transportation fueling can accommodate a broad range of alternate fuels , aviation fueling needs are specific, such as the fuel not freezing at altitude or become too viscous to flow properly or of low bulk energy density that shortens range. The fuel must also be compatible with legacy aircraft, some of which are more than 50 years old. US civil aviation alone consumes nearly 14 billion gallons. The enormity of the problem becomes overwhelming, and the aviation industry is taking alternate fueling issues very seriously.
Biofuels algae, cyanobacteria, halophytes, weeds that use wastelands, wastewater and seatwater , when properly sourced, have the capacity to be drop-in fuel replacements for petroleum fuels. As such, biojet from such sources solves the aviation CO2 emissions issue without the downsides of 'conventional' biofuels, such as competing with food and fresh water resources.
Of the many current fundamental problems, the major biofuel problem is cost. Both research and development and creative engineering are required to reduce these biofuels costs. The authors' current research is aimed at aiding industry efforts in several areas.
They are considering different modeling approaches, growth media and refining approaches, different biologic feedstocks, methods of sequestering carbon in the processes, fuel certification for aviation use and, overall, ensuring that biofuels are feasible from all aspects - operability, capacity, carbon cycle and financial.
Synthetic fuel production via carbon neutral cycles with high temperature nuclear reactors as a power source. This paper analyzes a number of carbon neutral cycles, which could be used to produce synthetic hydrocarbon fuels. Synthetic hydrocarbons are produced via the synthesis of Carbon Monoxide and Hydrogen. In addition the cycles will be coupled to a small modular Nuclear Reactor SMR as a power and heat source. The goal of this analysis is to reduce or eliminate the need to transport diesel and other fossil fuels to remote regions and to provide a carbon neutral, locally produced hydrocarbon fuel for remote communities.
The technical advantages as well as the economic case are discussed for each of the cycles presented. Full Text Available We propose a hypothesis that fuels will continue to be critical elements of future energy systems. The reasons behind this are explored, such as the immense benefits conferred by fuels from their low cost of storage, transport, and handling, and especially in the management of the seasonal swing in heating demand for a country with a summer and winter season such as the UK.
Empirical time-series data from Great Britain are used to examine the seasonal nature of the demand for liquid fuels , natural gas, and electricity, with the aid of a daily Shared Axis Energy Diagram. The logic of the continued need of fuels is examined, and the advantages and disadvantages of synthetic fuels are considered in comparison to fossil fuels. Wilson, I. Grant, E-mail: grant. We propose a hypothesis that fuels will continue to be critical elements of future energy systems.
SOEC pathways for the production of synthetic fuels. This resulted in a detailed overview of technologies involved in the production cycle of synthetic fuels , description of the proposed pathways and the architecture of the system Thermodynamic analysis of synthetic hydrocarbon fuel production in pressurized solid oxide electrolysis cells. A promising way to store wind and solar electricity is by electrolysis of H2O and CO2 using solid oxide electrolysis cells SOECs to produce synthetic hydrocarbon fuels that can be used in existing fuel infrastructure.
Pressurized operation decreases the cell internal resistance and enables In this paper, we present a thermodynamic analysis of synthetic methane and dimethyl ether DME production using pressurized SOECs, in order to determine feasible operating conditions for producing the desired For methane production, low temperature and high pressure operation could improve the system efficiency, but might lead to a higher capital cost. For DME production, high pressure SOEC operation necessitates higher operating temperature in order to avoid carbon formation at higher Full Text Available Fossil fuels depletion and increasing environmental impacts arising from their use call for seeking growing supplies from renewable and nuclear primary energy sources.
However, it is necessary to simultaneously attend to both the electrical power needs and the specificities of the transport and industrial sector requirements. A major question posed by the shift away from traditional fossil fuels towards renewable energy sources lies in matching the power demand with the daily and seasonal oscillation and the intermittency of these natural energy fluxes.
Huge energy storage requirements become necessary or otherwise the decline of the power factor of both the renewable and conventional generation would mean loss of resources. On the other hand, liquid and gaseous fuels , for which there is vast storage and distribution capacity available, appear essential to supply the transport sector for a very long time ahead, besides their domestic and industrial roles.
Within this context, the present assessment suggests that proven technologies and sound tested principles are available to develop an integrated energy system, relying on synthetic fuels. The principles and means are already available to develop a carbon-neutral synthetic fuel economy. Process of producing a fuel , etc. This invention has for its object a process of producing fuels by separating a light oil from primary tar, characterized by a succession of operations comprising preliminary removal of phenols from the oils, removing sulfur completely by the application of suitable catalysts and an agent to fix the free sulfur as hydrogen sulfide; finally, washing to remove ethylenes, pyridines, and impurities from the treatment.
Process for producing nuclear reactor fuel oxides. The NH 3 produced replaces the hydrogen which would otherwise be required for reduction in this process. Preliminary evaluation of fuel oil produced from pyrolysis of waste It could be refined further to produce domestic kerosene and gasoline. The physical and structural properties of the fuel oil produced compared favorably with that of Aviation fuel JP-4 a wide-cut US Air force fuel.
Presently African countries are importing aviation fuels. The fuel oil produced from the pyrolysis of waste water Development of fuel cell systems for aircraft applications based on synthetic fuels. Pasel, J. At present, in the aviation sector considerable scientific project work deals with the development of fuel cell systems based on synthetic fuels to be integrated in future aircraft.
The benefits of fuel cell systems in aircraft are various. They offer the possibility to simplify the aircraft layout. Important systems, i. Additionally, the energy demand for ice protection can be covered assisted by fuel cell systems. These measures reduce the consumption of jet fuel , increase aircraft efficiency and allow the operation at low emissions. Additionally, the costs for aircraft related investments, for aircraft maintenance and operation can be reduced.
On the background of regular discussions about environmental concerns global warming of kerosene Jet A-1 and its availability, which might be restricted in a few years, the aircraft industry is keen to employ synthetic , sulfur-free fuels such as Fischer-Tropsch fuels. Within this field of research the Institute of Energy Research IEF-3 in Juelich develops complete and compact fuel cell systems based on the autothermal reforming of these kinds of fuels in cooperation with industry.
This paper reports about this work. Method of producing granulated ceramic nuclear fuels. For the production of granulated ceramic nuclear fuels with a grain size spectrum as narrow as possible it is proposed to suspend the nuclear fuel powder in a non-aqueous solvent with small content of hydrogen e.
As binding agent polybutyl methane acrylate in dibutyl phthalate is proposed. The method is described by the example of UO 2 -powder in trichloroethylene. The dry granulated material is produced in one working step. UWI [de. Romania, producer and consumer of nuclear fuel. A historical sketch of the activity of Romanian Rare Metals Enterprises is presented stressing the valorization of rare metals like: - radioactive metals, uranium and thorium; - dispersed rare metals, molybdenum, monazite; - heavy and refractory metals, titanium and zirconium; rare earths, lanthanides and yttrics.
The beginning and developing of research in the nuclear field is in closed relation to the existence on the domestic territory of important uranium ores the mining of which begun early in Concomitantly with the ore mining, geological research was developed covering vast areas of country's surface and using advanced investigation tools suitable for increasing depths.
The next step in the nuclear fuel program was made by building a uranium concentrate as ammonium or sodium diuranate plant. Two purification units for processing the uranium concentrate to sintered uranium dioxide powder were completed and commissioned at Feldioara in The quality of the uranium dioxide product meets the quality standards requirements for CANDU type nuclear fuel as certified in Currently, part of the fuel load of Cernavoda reactor is fuel element clusters produced by Nuclear Fuel Plant at Pitesti of sintered powder processed at Feldioara.
A list of strategic objectives of the Uranium National Company is presented among which: - maintaining the uranium mining and milling activities in close relation with the fuel requirements of Cernavoda NPP; continuing geological research in promising zones, to find new uranium orebodies, easy to mill cost effectively; decreasing the environmental impact in the geological research areas, in mining and transport affected areas and in the processing plants.
The fuel demand of current operation of Cernavoda NPP Unit 1 as well as of future Unit 2 after commissioning are and will be satisfied by the. Method of producing encapsulated thermonuclear fuel particles. A method of producing a fuel particle is disclosed, which comprises forming hollow spheroids which have a mass number greater than 50, immersing said spheroids while under the presence of pressure and heat in a gaseous atmosphere containing an isotope, such as deuterium and tritium, so as to diffuse the gas into the spheroid and thereafter cooling said spheroids up to about 77 0 Kelvin to about 4 0 Kelvin.
Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels. The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels.
Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity e. For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.
Some technical subjects on production of hydrocarbon fuel from synthetic gas. Since fuel oil meeting the requirements of current petroleum products can be produced by SASOL F-T synthetic process, the manufacturing process of hydrocarbon fuel oil from the coal-derived synthesis gas, downstream processes are being successively investigated.
Mobile M-gasoline, MTG, process which produces gasoline from the natural gas-derived synthesis gas through methanol went into commercial operation in New Zealand in Although the gasoline suffices the quality of commercial gasoline by both fixed bed and fluidized bed systems, the price and service life of catalyst and control of by-product durene must be improved.
Any STG processes have not been completed yet and the yield and quality of gasoline are inferior to those of gasoline produced by the MTG process. Applying two-stage process, the STG process will be more economically effective. Full Text Available Color of cloth dyed with Awa natural indigo is quantitatively compared with color of the cloth dyed with synthetic indigo.
Results showed that: 1 color produced by Awa natural indigo is bluer and brighter than color produced by synthetic indigo; 2 a single Gaussian function fits the profile of the running of color produced by Awa natural indigo and the running of color produced by synthetic indigo prepared with sodium hydrosulfite approximates a linear sum of two Gaussian functions; 3 before and after washing, color is quantitatively more uneven when produced by Awa natural indigo than when produced by synthetic indigo; 4 the diffusion coefficient of Awa natural indigo is lower than that of synthetic indigo; 5 color superiority of Awa natural indigorelates to smaller diffusion coefficient, slower reduction, poorer penetration, and higher dye aggregation.
High temperature blankets for the production of synthetic fuels. The application of very high temperature blankets to improved efficiency of electric power generation and production of H 2 and H 2 based synthetic fuels is described. Separate coolant circuits are used for the two temperature zones: water for the low temperature structure, and steam or He for the hot interior.
Comparison of alternate fuels for aircraft. Liquid hydrogen, liquid methane, and synthetic aviation kerosene were assessed as alternate fuels for aircraft in terms of cost, capital requirements, and energy resource utilization. Fuel transmission and airport storage and distribution facilities are considered. Environmental emissions and safety aspects of fuel selection are discussed and detailed descriptions of various fuel production and liquefaction processes are given.
Technological deficiencies are identified. Hybrid energy systems using nuclear heat sources can economically produce load-following electrical power by exploiting the surplus generation capacity available at night or seasonally to make synthetic fuel. Vehicle fuel is the only current energy use large enough to absorb all the energy capacity that might be diverted from the power industry, and its ease of storage obviates problems with discontinuous synfuel production.
The potential benefits and challenges of synfuels integration are illustrated by the production of methanol from natural gas as a source of carbon using steam from a light water nuclear power reactor which is assumed to be available in accord with a year's worth of power demand data. Methanol's synthesis process is easily adapted to using C heat from a light water reactor and this simple compound can be further processed into gasoline, biodiesel, or dimethyl ether, fuels which can be used with the current vehicle fleet.
A supplemental feed to the methanol process of natural gas for energy allows operation at constant full rate when the nuclear heat is being used to produce electrical power. The higher capital costs of such a system are offset by a lower cost of heat and power production from a large base load type of plant and by reduced costs associated with much lower CO2 emissions. Other less tangible economic benefits of this and similar hybrid systems include better use of natural resource for fuels and greater energy services security from the domestic production of vehicle fuel.
Commercial scale Sunexus CO2 Solar Reformer plant designs, proposed in this report, should be able to utilize waste CO2 from a wide variety of industrial sources to produce a directly usable synthetic diesel fuel that replaces petroleum derived fuel , thus improving the United States energy security while also sequestering CO2. Our material balance model shows that every 5. Details are provided in the mass and energy model in this report. MHD power generation for the synthetic-fuels industry.
The integration of open cycle MHD with various processes for the recovery of hydrocarbons for heavy oil deposits, oil sands, and oil shales are examined along with its use in producing medium Btu gas, synthetic natural gas and solvent refined coal. The major features of the MHD cycle which are of interest are: a the ability to produce hydrogen through the shift reaction by introducing H 2 O into the substoichiometric combustion product flow exiting the MHD diffuser, b the use of high temperature waste heat in the MHD exhaust, and c the ability of the seed in the MHD flow to remove sulfur from the combustion products.
Therefore the use of the MHD cycle allows coal to be used in an environmentally acceptable manner in place of hydrocarbons which are now used to produce process heat and hydrogen. The appropriate plant sizes are in the range of 25 to 50 MWe and the required MHD generator enthalpy extraction efficiencies are low. Sale of electricity produced , over and above that used in the process, can provide a revenue stream which can improve the economics of the hydrocarbon processing.
This, coupled with the replacement of coal for hydrocarbons in certain phases of the process, should improve the overall economics, while not requiring a high level of performance by the MHD components. Therefore, this area should be an early target of opportunity for the commercialization of MHD.
Implementation and validation of synthetic inertia support employing series produced electric vehicles. The high integration of renewable energy resources inverter connected replacing conventional generation reduces the available rotational inertia in the power system.
This introduces the need for faster regulation services including synthetic inertia services. These services could potentially This work evaluates and experimentally shows the capability and limits of EVs in providing synthetic inertia services. Three series produced EVs are used during the experiment. The results show the performance of the EVs in providing It shows also that, on the contrary of synchronous inertia, synthetic inertia might lead to unstable frequency behavior Process to produce homogenized reactor fuels.
The fuels consist of a mixture of PuO 2 and UO 2. In order to increase the homogeneity of mechanically mixed fuels the pellets are sintered in a hydrogen atmosphere with a sufficiently low oxygen potential. By the reduction process water vapor is obtained increasing the pressure within the PuO 2 particles and causing PuO 2 to be pressed into the uranium oxide structure.
DG [de. A reactor power plant is proposed that can meet base load electrical demand, while the remainder can generate synthetic fuels and meet intermittent electrical demands. Process and device to produce fuel briquettes. A two-stage process for the production of briquettes consisting essentially of cellulose sawdust, peanut shells is proposed.
The fuel material in case with additives is molded by high pressure to pellets of the size of a few centimeters. The pellets are mixed with flammable binding agents like paraffin, wax, polyethylene etc. A suited molding device is described. The wax content could be lowered with respect to known processes. Synthetic glycerin produced by the hydrogenolysis of carbohydrates may be safely used in food, subject to the provisions of this section: a It shall contain not in Attempt to produce silicide fuel elements in Indonesia.
All quality controls required have been imposed to the feeds, intermediate, as well as final products throughout the production processes of the two fuel elements. Full Text Available Traditionally materials have been associated with a series of physical properties that can be used as inputs to production and manufacturing. These artificial materials can be described as synthetic because they are the outcome of various qualities that are not necessarily true to the original matter, but they are the combination of two or more parts, whether by design or by natural processes.
The aim of this paper is to investigate the potential of architectural surfaces to produce effects through the invention of new breeds of artificial matter, using micro-scale details derived from Nature as an inspiration. Widespread implementation of polymer electrolyte membrane fuel cell PEMFC powerplants for stationary and vehicular applications will be dependent in the near future on using readily available hydrocarbon fuels as the source of the hydrogen fuel.
Methane and propane are ideal fuels for stationary applications, while methanol, gasoline, and diesel fuel are better suited for vehicular applications. The cell also underwent four successful thermal cycles with no appreciable loss in performance. The effects of temperature, gas composition, fuel utilization stoics and thermal cycle on cell performance are described.
Evaluation of safety, performance and emissions of synthetic fuel blends in a Cessna Citation II. Prior to being used in aviation, alternative fuels have to be tested thoroughly to ensure safe operation. At Delft University of Technology, a test programme was performed to evaluate the safety, performance and emissions of synthetic fuel blends. During test preparations, compatibility of the. Synthetic fuel production costs by means of solid oxide electrolysis cells. The purpose of this paper is to provide an overview of fuel production costs for two types of synthetic fuels — methanol and methane, along with comparable costs for first and second generation biodiesel, two types of second generation bioethanol, and biogas.
Ototoxic potential of JP-8 and a Fischer-Tropsch synthetic jet fuel following subacute inhalation exposure in rats. This study was undertaken to identify the ototoxic potential of two jet fuels presented alone and in combination with noise. Rats were exposed via a subacute inhalation paradigm to JP-8 jet fuel , a kerosene-based fuel refined from petroleum, and a synthetic fuel produced by the Fischer-Tropsch FT process.
The objectives of this study were to identify a lowest observed adverse effect level and a no observed adverse effect level for each jet fuel and to provide some preliminary, but admittedly, indirect evidence concerning the possible role of the aromatic hydrocarbon component of petroleum-based jet fuel on hearing. Additional groups were exposed to various fuel concentrations followed by 1 h of an octave band of noise, noise alone, or no exposure to fuel or noise.
In contrast to the effects of JP-8 on noise-induced hearing loss, FT exposure had no effect by itself or in combination with noise exposure even at the highest exposure level tested. Despite an observed loss in DPOAE amplitude seen only when JP-8 and noise were combined, there was no loss in auditory threshold or increase in hair cell loss in any exposure group. Preliminary evaluation of fuel oil produced from pyrolysis of low The wax content decreases as temperature increases. The highest quantity The producers of Fossil fuel produced radioactivities and their effect on foodchains.
The environmental impact of radioactivities produced from fossil fuel burning is not necessarily small compared with that of nuclear energy. The effect of these radioactivities on the foodchain through seafoods is discussed. Agricultural residues as fuel for producer gas generation. This paper reports on results from a series of tests with four different types of agricultural residues as fuel for producer gas generation.
The fuels are coconut shells, coconut husks, pelletized wheat-straw and pressed sugar cane. The tests were made with a 73 Hp 50 kW agricultural tractor diesel engine equipped with a standard gasifier developed for wood chips in Sweden, and run on a testbed at the Swedish National Machinery Testing Institute. The gas composition, its calorific value and temperature, the pressure drop and the engine power were monitored. Detailed elementary analysis of the fuel and gas were carried out.
Observations were also made regarding the important aspects of bridging and slagging in the gasifier. The tests confirmed that coconut shells make an excellent fuel for producer gas generation. After 8 hours of running no problems with slags and bridging were experienced. Coconut husks showed no bridging but some slag formation. The gasifier operated satisfactorily for this fuel. Pelletized wheat straw and pressed sugar cane appeared unsuitable as fuel in the unmodified test gasifier Type F due to slag formation.
It is important to note, however, that the present test results are not optimal for any of the fuels used, the gasifier being designed for wood-chips and not for the test- fuels used. Tests using approximately modified gasifiers are planned for the future. Electronuclear fissile fuel production. A linear accelerator fuel generator is proposed to enrich naturally occurring fertile U or thorium with fissile Pu or U for use in LWR power reactors.
High energy proton beams in the range of 1 to 3 GeV energy are made to impinge on a centrally located dispersed liquid lead target producing spallation neutrons which are then absorbed by a surrounding assembly of fabricated LWR fuel elements. The accelerator-target design is reviewed and a typical fuel cycle system and economic analysis is presented. There is a significant saving in natural uranium requirement which is a factor of 4. The linear accelerator fuel regenerator and producer assures a long-term supply of fuel for the LWR power economy even with the restraint of the non-proliferation policy of no reprocessing.
It can also supply hot-denatured thorium U fuel operating in a secured reprocessing fuel center. LEU fuel element produced by the Egyptian fuel manufacturing pilot plant. The plant uses uranium hexafluoride UF 6 , Radiological safety aspects during design, construction, operation, and all reasonably accepted steps should be taken to prevent or reduce the chance of accidents occurrence. Core fueling to produce peaked density profiles in large tokamaks.
Peaking the density profile increases the usable bootstrap current and the average fusion power density; this could reduce the current drive power and increase the net output of power producing tokamaks. The use of neutral beams and pellet injection to produce peaked density profiles is assessed. We show that with radially ''hollow'' diffusivity profiles and no particle pinch moderately peaked density profiles can be produced by particle source profiles which are peaked off-axis.
The fueling penetration requirements can therefore be relaxed and this greatly improves the feasibility of generating peaked density profiles in large tokamaks. In particular, neutral beam fueling does not require MeV particle energy.
In system with no power production requirement e. Nuclear fuel assembly with improved spectral shift- producing rods. This patent describes a nuclear reactor having fuel assemblies and a moderator-coolant liquid flowing through the fuel assemblies, each fuel assembly including an organized array of nuclear fuel rods wherein the moderator-coolant liquid flows along the fuel rods, at least one improved spectral shift- producing rod disposed among the fuel rods.
The spectra shift- producing rod consists of: a an elongated hollow hermetically-sealed tubular member; b a weakened region formed in a portion of the member, the portion being subject to rupture at a given level of internal pressure; and c burnable poison material contained in the member which generates gas in the member as operation of the reactor proceeds normally, the material being soluble in the moderator-coolant liquid when brought into contact therewith; d the given level of internal pressure being less than the maximum level of internal pressure normally expected to be generated within the member by the poison material by normal operation of the reactor.
A single step methane conversion into synthetic fuels using microplasma reactor. Direct conversion of natural gas into synthetic fuels such as methanol attracts keen attention because direct process can reduce capital and operating costs of high temperature, energy intensive, multi-step processes. We report a direct and selective synthesis of organic oxygenates such as methanol,. Some regional costs of a synthetic fuel industry: The case of illinois.
The Federal Government's efforts to induce development of a coal-based synthetic fuel industry include direct subsidies, tax concessions, and assurances that it will purchase the industry's output, even if above the market price. In this note it is argued that these subsidies will enable this industry to secure a region's largest and lowest-cost coal deposits and that the costs imposed on other coal users will be substantial. Moreover, because the lowest-cost coal deposits will be committed to synthetic fuels production regardless of the industry's commercial viability, distortions in regional coal markets will develop.
If economic efficiency requires that the price of the resource reflect its replacement value, then a State government is justified in imposing a tax on coal destined for subsidized synthetic fuel plants. Amounts of such a tax, based on the higher costs of coal that must be accepted by other users as the result of the subsidized synthetic fuel plants' preempting the largest and lowest-cost deposits, are estimated for the case of Illinois strippable coal.
Prospects for production of synthetic liquid fuel from low-grade coal. Full Text Available In the paper, we compare the energy costs of steam and steam-oxygen gasification technologies for production of synthetic liquid fuel. Results of mathematic simulation and experimental studies on gasification of low-grade coal are presented. Process for producing a fuel suitable for degassing from refuse. Utilization of the heat energy of refuse in waste incineration plants is time-consuming and expensive due to high investment and operation costs.
The inventor recommends to process the refuse to a sterile, handy and storable fuel. For this propose the refuse should be crushed, kneaded and pressed. The briquettes produced in this way should be dried. The corrosion of spent UO2- fuel in synthetic groundwater.
Segments of fuel and clad have been leached in deionized water and in groundwater. The leachants were centrifuged through membrane filters. The results are discussed in terms of preferential leaching, solubility limitations and adsorption effects. For U an apparent saturation at about ppb was observed.
Pu also appeared to attain saturation at a few ppb. Attempts to impose reducing conditions showed decreased leach rates. Biomass resources are limited and the sustainable use of them needs to be prioritized. Future energy systems will require The purpose of this paper is to provide an overview of fuel production cost for two types of synthetic fuels — methanol and methane, and comparable costs of biodiesel, bioethanol and biogas The corrosion of spent UO2 fuel in synthetic groundwater.
Congruent dissolution was only attained at pH values of about 4. When reducing conditions were imposed on the pH 8. The hypothesis that alpha radiolytic decomposition of water is a driving force for UO 2 corrosion even under reducing conditions has been examined in leaching tests on low burnup low alpha dose-rate fuel. No significant effect of alpha radiolysis under the experimental conditions was detected. Thermodynamically the calculated uranium solubilities in the pH range Full Text Available In the present paper, development of producer gas fuelled 4 stroke diesel engine has been investigated.
Producer gas from biomass has been examined and successfully operated with 4 stroke diesel engine. The effects of higher and lower loads were investigated on the dual fuel mode. The experimental investigations revealed that at lower loads dual fuel operation with producer gas shows lower efficiency due to lower combustion rate cause by low calorific value of the producer gas. Power output was almost comparable to diesel power with marginal higher efficiency.
Producer gas is one such technology which is environmentally benign and holds large promise for future. Full Text Available Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes.
It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol.
We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors. Towards a methanol economy: Zeolite catalyzed production of synthetic fuels. The main focus of this thesis is zeolite catalyzed conversion of oxygenates to hydrocarbon fuels and chemicals.
Furthermore, conversion of ethane to higher hydrocarbons has also been studied. The object was to investigate if the presence of methanol in the feed could enhance the conversion of ethane, but in all cases the opposite is observed; the presence of methanol actually suppresses the conversion of ethane When 2-propanol or 1-butanol is converted over H-ZSM-5, the total conversion capacities of the catalyst are more than 25 times higher than for conversion of methanol and ethanol.
Final report. This international Collaborative Task is coordinated by Finland. Modern renewable diesel fuels have excellent physical and chemical properties, in comparison to traditional crude oil based fuels. Purely paraffinic fuels do not contain aromatic compounds and they are totally sulphur free. The combustion properties are better than those of crude oil based fuels and FAME, because they have very high cetane numbers and contain no polyaromatic hydrocarbons PAH.
With low HVO density, viscosity and distillation temperatures, these advantageous properties allow far more advanced combustion strategies, such as very high exhaust gas recirculation EGR rates or extreme Miller timings, than has been possible with current fossil fuels. Combining hybrid cars and synthetic fuels with electricity generation and carbon capture and storage.
We examined the co-evolution of the transportation, and electricity and heat generation sectors in the Netherlands until using a MARKAL bottom-up cost optimisation model. All scenario variants investigated indicate a switch away from crude oil-based diesel and petrol for transportation.
Lowest overall CO 2 abatement cost is achieved by accommodating transportation first and using relatively expensive options for emissions reduction in electricity generation if needed. Biomass and carbon capture and storage CCS are used to full potential. Transportation CO 2 emissions are reduced by switching to ethanol or bio-based synthetic fuels combined with CCS, and series hybrid cars if needed. Depending on the availability of biomass and carbon storage capacity, electricity is produced from biomass, coal with CCS, or wind complemented with natural gas.
Investment costs are mostly determined by the cost of cars and electricity generation capacity. We observe competition for limited biomass supply and CO 2 storage capacity between the transportation and power sectors. Technology for producing synthetic cast iron for nuclear power station parts.
A technology was developed and implemented for producing grades SCh through SCh synthetic cast iron in industrial-frequency induction melting furnaces. Alternative innoculations with ferrosilicon and silicocalcium and alloying with chrome and nickel were studied.
The mechanical properties and structure of cast irons produced by various technological methods were studied. The research showed that the sector's plants, equipped with industrial-frequency induction furnaces, can produce high-quality synthetic cast irons containing flake graphite for nuclear-power-station casting, without the use of expensive innoculants.
Careful observance of the melting and innoculating technologies makes it possible to produce SCh 40 cast iron, without cementite inclusions, by innoculating with FS 75 ferrosilicon in the amount of 0. Using an innoculant mixture of 0. Developments in production of synthetic fuels out of Estonian shale. Estonia is still the world leader in utilization of oil shale.
Enefit has cooperated with Outotec to develop a new generation of solid heat carrier technology - Enefit, which is more efficient, environmentally friendlier and has higher unit capacity. Breakeven price of oil produced in Enefit process is competitive with conventional oils.
The new technology has advantages that allow easy adaptation to other oil shales around the world. Hydrotreated shale oil liquids have similar properties to crude oil cuts. Design for a shale oil hydrotreater unit can use process concepts, hardware components, and catalysts commercially proven in petroleum refining services. Most of the material in plants is cellulose , hemicellulose, or lignin.
None of these substances is amenable to the This is especially the case for non-food-crop biomass, such as corn stover, switchgrass, prairie Coal-to-Liquids Technologies 39 Unfortunately, annual variations in weather. Biofuel production from wood is an interesting option for the energetic use of wood.
Various bio fuels could be produced from woody biomass, such as methanol, Fischer-Tropsch FT fuels , methane or hydrogen. FT liquids and bio-SNG can be distributed and used via existing infrastructures and therefore fit best today's fossil infrastructure. On an assessment basis from primary to mechanical energy both fuels have pros and cons. For the consolidation of crucial information, i. Based on such plants, a detailed evaluation of both fuel chains will be possible.
A light hydrocarbon fuel processor producing high-purity hydrogen. This fuel processor has been integrated with a 5-kW fuel cell producing electricity and hot water. Fuel characteristics and trace gases produced through biomass burning. Biodiversitas Because using fire is cheap, easy and quick and also support the companies purpose in achieving yearly planted area target. Forest management and land use practices in Sumatra and Kalimantan have evolved very rapidly over the past three decades.
Poor logging practices resulted in large amounts of waste will left in the forest, greatly elevating fire hazard. Failure by the government and concessionaires to protect logged forests and close old logging roads led to and invasion of the forest by agricultural settlers whose land clearances practices increased the risk of fire.
Several field experiments had been done in order to know the quality and the quantity of trace produced during biomass burning in peat grass, peat soil and alang-alang grassland located in South Sumatra, Indonesia. Result of research show that different characteristics of fuel burned will have the different level also in trace gasses produced. Peat grass with higher fuel load burned produce more trace gasses compared to alang-alang grassland and peat soil.
Hydrogen and synthetic fuel production using pressurized solid oxide electrolysis cells. Wind and solar power is troubled by large fluctuations in delivery due to changing weather. As the catalyst operates at elevated pressure the fuel production system can be simplified by operating the SOEC at elevated pressure. Here we present the results of a cell test with pressures ranging from 0. The cell was tested both as an SOEC The bio refinery; producing feed and fuel from grain.
It is both possible and practicable to produce feed and fuel from grain. Using the value of grain to produce renewable energy for transport, while using the remaining protein content of the grain as a valuable protein source for livestock and for fish, can be seen as a complimentary and optimal use of all the grain constituents.
Consideration must be given to maximise the value of the yeast components, as substantial yeast is generated during the fermentation of the grain starch to produce ethanol. Yeast is a nutritionally rich feed ingredient, with potential for use both as feed protein and as a feed supplement with possible immunity and gut health enhancing properties. Bioprocessing, with the consequent economies of scale, is a process whereby the value of grain can be optimised in a way that is traditional, natural and sustainable for primarily producing protein and oil for feed with a co-product ethanol as a renewable fuel.
All rights reserved. Synthetic fuels and the environment: an environmental and regulatory impacts analysis. The program year for which the development goal of 1. The program plan is now proposed to have two stages to ensure, among other things, better environmental protection: an initial stage emphasizing applied research and development R and D , including environmental research, followed by a second stage that would accelerate deployment of those synthetic fuel technologies then judged most ready for rapid deployment and economic operation within the environmental protection requirements.
These program changes have significantly expanded the scope of technologies to be considered in this environmental analysis and have increased the likelihood that accelerated environmental R and D efforts will be successful in solving principal environmental and worker safety concerns for most technologies prior to the initiation of the second stage of the accelerated deployment plan. Information is presented under the following section headings: summary; study description; the technologies and their environmental concerns including, coal liquefaction and gasification, oil shale production, biomass and urban waste conversion ; regulatory and institutional analyses; and environmental impacts analysis including air and water quaility analyses, impacts of carbon dioxide and acid rain, water availability, solid and hazardous wastes, coal mining environmental impacts, transportation issues, community growth and change, and regional impacts.
Additional information is presented in seventeen appendixes. Characteristics of sustainable bio-solid fuel produced from sewage sludge as a conventional fuel substitute. Safely final disposal of sewage sludge which is being increased every year has already become serious problems.
As one of the promising technologies to solve this problem, thermal drying method has been attracting wide attention due to energy recovery from sewage sludge. This plant has been successfully operated many times and is now designing for scale-up.
So they can be utilized to supply energy in the coal power plant and cement kiln etc. Characteristics including proximate analysis, ultimate analysis, contents of heavy metals, wettability etc. Directions and prospects of using low grade process fuel to produce alumina.
Full Text Available Power consumption across the globe is constantly increasing for a variety of reasons: growing population, industrialization and fast economic growth. The most widespread gaseous fuel — natural gas — has the low production cost. It is times cheaper than liquid fuel production and times cheaper than coal production. When natural gas is transported to distances from 1. Plants powered by natural gas have the higher efficiency as compared to the plants operating on other types of fuel.
They are easier and cheaper to maintain and are relatively simple in automation, thus enhancing safety and improving the production process flow, do not require complicated fuel feeding or ash handling systems.
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The downdraft gasifier is characterized by the high gas temperature at the exit, relatively oil cleanness, and low ash contents, thus being more suitable for small-scale applications. As shown in Figure 16 c, in a cross-flow gasifier, feedstock moves downward from the top of the reactor, while air is brought in from the side; the producer gas leaves at the same level on the opposite side, and the ash is removed at the bottom. The combustion zone is formed around the air entrance, and the pyrolysis and drying zones are formed in the upper part of the gasifier.
Ash and producer gas are removed from the gasifier at higher temperatures, which results in a low carbon conversion efficiency. Another type of fixed bed gasifier is a two-stage fixed bed quartz reactor Figure In this reactor, the reactor tube has two stages and is heated by two electrical furnaces, separately.
The feedstock particles are put in the first stage, and the catalyst is put in the second stage to carry out the catalytic reforming of volatiles. During the steam gasification, steam entering the reactor passes through a branch inlet, which is welded to the main reactor at 50 mm below the pyrolysis bed. Among pyrolysis and gasification technologies, fluidized bed reactors are the best choice as a result of its flexibility for fuel types and high efficiency.
In comparison to the fixed bed reactor, it has the advantage of uniform temperature distribution in the reduction zone. This temperature uniformity is achieved by the use of beds made of fine particle materials, such as sand, in which the air flow is circulated to fluidize the bed.
It also boasts of easy control, convenient char collection, and low cost. Two main fluidized bed reactors are currently in use: a bubbling fluidized bed and b CFB. In bubbling fluidized beds, sand is often used as the solid phase of the bed. The feedstock particles are introduced into the hot sand bed, which is fluidized by the gas. The high heat transfer rate of fluidized sand leads to the rapid heating of feedstock particles and the attrition ablation between them.
In the bubbling fluidized bed pyrolyzer, the flow rate of fluidized gas controls the residence time of solids and volatiles and the residence time of char is greater than that of steam. The pyrolyzer has characteristics of a simple structure, simple operation, and mature technology.
However, this type of reactor is expensive to operate as a result of scale-up constraints. Large-scale heat transfer in the pyrolyzer bed must be carefully considered. The fine-grained material is placed above the grate, where the feedstock is transported and reacted. However, there is some carbon loss with ash. For CFB reactors, the recirculated product gas, sand, and biomass particles move together. The CFB pyrolyzer Figure 20 has been a well-understood technology and suitable for large throughputs.
As a result of higher gas velocity, char is more easily worn, which leads to a higher char content in the collected bio-oil. In a CFB gasifier Figure 21 , the bed material circulates continuously between the reactor and the cyclone separator.
The bed material and char are captured and returned to the reactor, and the ash is separated in the separator. The process technology of the entrained flow pyrolyzer is simple, but the heat transfer performance of hot gas and solid particles is poor. The high gas flow makes it difficult to collect liquid, and thus, the liquid yield is low. Therefore, most of the development of these reactors has not been as successful as expected.
The design of the entrained flow gasifiers is simple: operating at a higher temperature and higher heating rates and allowing for better efficiency and cleaner syngas. The costly feed preparation is needed for woody biomass. The plasma reactor generally includes the plasma generator, reaction chamber, and part of the accessories. The external heat source is provided by the plasma. Pyrolysis does not require the direct emission of CO 2 nor demands a large amount of water.
It provides high energy density and high temperature conditions for the reaction; therefore, the sample is heated rapidly to a high temperature, and the reaction speed is fast. These conditions favor hydrocarbon cracking and, thus, provide potential solutions to the problems in the traditional pyrolysis process, such as low gas yields and the generation of heavy oil.
This method also has practical significance for producing syngas and coke from biomass raw materials. The results show that the higher the mixing enthalpy of coal gas, the higher the coal conversion rate and the higher the yield of light gases. With the increase of the H 2 concentration, the carbon conversion is enhanced and the yields of CO and C 2 H 2 increase correspondingly. For the vacuum reactor, the feedstock is thermally degraded under a reduced pressure.
The volatiles are quickly removed from the reactor and condensed. The residence time of solids in the reactor is very long, while that of volatiles is very short. Therefore, it is not really a FP process. The reactor has the advantage of no carrier gas requirement and less char in liquid products.
It can handle larger particles than most FP reactors. The rotating cone reactor Figure 23 is a novel reactor type for flash pyrolysis. Hot sand and feedstock are fed into a rotating heated cone using centrifugation. The requirement of the carrier gas in this reactor is much lower than that of the fluidized bed. The various study examples for reactors are displayed in Table 7. Many reactor configurations have been developed and tested, and Table 8 briefly summarizes their advantages and disadvantages.
Table 7. Summary of the Reactor Characteristics Described in the above Reactors. Table 8. Comparison of Different Types of Reactors. Each reactor has its own advantages and disadvantages. In practical application, it is necessary to select the appropriate reactor type according to the purpose. Different reactors have different requirements on the particle size, feeding mode, separation equipment, etc. For pyrolysis, a high heating rate, fast condensation rate of volatile matter, and stable pyrolysis temperature are the keys to maximize the tar yield.
The FP reactor is the core of realizing these three conditions. The study of the pyrolysis mechanism should be regarded as the key to make a breakthrough in FP, and the study of the FP reactor can be promoted more effectively by further exploring the mechanism. For gasification, it is difficult to realize large-scale and commercial production of syngas.
The next stage of scientific research must focus on energy reduction and further improvement of gasification efficiency. The development of advanced and low-cost catalysts for the production of hydrocarbon fuels, chemicals, and syngas via various upgrading technologies has been the subject of investigation recently. The main types of catalysts used in recent upgrading technologies are summarized in Tables 5 and 9 — Table 9.
Table Noble metals Pt, Pd, and Ru and transition metals Ni and Co are widely used as active sites during the conversion of volatiles. These catalysts are effective in decreasing oxygenated compounds, such as phenols, acids, and sugars. TiO 2 , ZrO 2 , ZrO 2 , and TiO 2 and their modified catalysts with incorporation of Ce, Ru, or Pd are effective to convert the lignin-derived oligomers to monomeric phenolic compounds.
Lin et al. They found that the MgO support was the best among them in the conversion process. Subsequently, Zhu et al. It is related to the catalytic activity of Ni. Thus, it can be concluded that using a metal-based catalyst in the pyrolysis process can change the composition of the products. The oil content also shows a slight increase after these catalysts are used.
SiO 2 with weak acidity and medium porosity showed good catalytic activity for removing oxygenated compounds, especially in combination with Al 2 O 3. For the typical base metal oxides, such as MgO or CaO, they could also promote fragmentation reactions. Generally, active metal atoms in the bimetal oxides by synthesis can improve the selectivity of desirable chemicals.
Comparatively, metal oxides are more suitable for syngas production and water removal. Oxygen is removed in the form of H 2 O and CO 2. Murugappan et al. The sulfided CoMo and NiMo catalysts are also used for desulfurization that is resistant to any sulfur-containing compounds in the feedstock. In section 4. Hydrocracking without catalysts was operated in the first stage, and catalytic hydrotreatment was conducted in the second stage. It was reported that deoxygenation with NiMo catalysts was more effective than that with CoMo.
The P-promoted catalyst showed a higher catalytic characteristic during bio-oil hydrotreating. Besides, noble metal catalysts are the most active in bio-oil hydrotreating. The catalysts used for reforming of biomass-derived volatiles and bio-oil play the following roles: 1 decreasing the activation energy of the cracking reaction, 2 decreasing the amount of gasifying agent, and 3 realizing the directional catalytic conversion.
Recently, the natural mineral catalysts and metal-supported catalysts represented by dolomite and a Ni-based catalyst, respectively, have been widely studied around the world. Other catalysts, such as alkali-metal and noble-metal-supported catalysts, are also investigated.
Minerals are homogeneous solids, which are formed naturally but usually have unfixed chemical composition and ordered atomic arrangement. These minerals can be used as catalysts directly or with some physical treatments such as calcining. Commonly, the mineral catalysts are cheaper than most other catalysts and have a certain activity for biomass gasification. To be specific, dolomite is one of the most representative mineral catalysts, which has been widely used in gaseous oil cracking.
Many previous literature reported its high efficiency for gaseous oil removal. For example, Gusta et al. As a result, different levels of gaseous oil conversion and overall gas yield during wood biomass gasification were obtained. Fe was found to be beneficial in improving the WGS reaction, when its content is lower than 0.
Yu et al. They found that dolomite with a larger average pore size could be more effective in oil removal, especially for the cracking of N. CaO and MgO appeared in the dolomite after the calcination was activated in eliminating biomass oil. In addition, the enhancement of activity of calcined dolomite could also be consistent with the increase of the surface area and pore size.
Additionally, Kuhn et al. It significantly improved the catalytic performance. Constantinou et al. Limonite is one of most important mineral resources of iron oxides, and its main component is goethite. The reserves of limonite are abundant, but the research on the development and utilization of limonite is very scarce because of the impurities in limonite and the fine mineral particles, which make it difficult to separate limonite. It is usually limited to the grinding production of iron oxide yellow pigment, partly used for adsorption and removal of H 2 S from the coal oven gas.
However, low-grade limonite can meet the iron content of the catalyst for gaseous oil cracking. Limonite is mainly composed of goethite FeOOH and contains Zhao et al. Raw limonite had lower activity for catalytic reforming of biomass gaseous oil under Ar, but the activity was quite improved with the change of the chemical composition of limonite FeOOH to Fe 2 O 3 , which can be seen from the XRD and transmission electron microscopy TEM images in Figures 24 and 25 ; the maximum H 2 yield Generally, the mineral catalyst can only be activated after thermal treatment, such as calcined and reduced.
The active components are mainly Ca, Mg, and Fe, which belong to alkali metal and transition metal. Meanwhile, the yields of CO, CH 4 , and some light hydrocarbons are inhibited. Additionally, alkali metal catalysts include alkali metal, alkaline earth metal oxides, and alkali metal carbonates such as K 2 CO 3 and Na 2 CO 3. Jiang et al. However, the alkali metal catalyst is difficult to use and difficult to recover in the process of biomass gasification.
Noble metal catalysts usually have an outstanding catalytic performance, in that they can produce a large amount of valuable products with a very low content. However, the expensive price of rare metals hinders the widespread application.
As Figure 26 showed, Mei et al. The metal particle size was smaller than 10 nm, and the metal particles were highly dispersed. In addition, kinetics showed that the decomposition of B was more likely to occur on smaller clusters rather than larger particles Figure Metallic Ni-based catalysts as the most common catalysts are favored by the researchers as a result of their commercial and economical characteristics.
Ni-based catalysts are often used to remove gaseous oil by CH 4 reforming to produce H 2 -rich syngas and are also active for dry methane and steam reforming. A lot of work has been focused on improving the preparation methods of catalysts to obtain more efficient performance, such as changing preparation steps, adjusting Ni loadings and the molar ratio between Ni and promoter, and optimizing the preparation parameters.
Except for the above modifications, Ni-based catalysts can also be modified by alloying with secondary transition metal Fe, Co, Mn, and Cu and using alkali metal or noble metal as the promoter. The common supports contain metal oxides, zeolite, and char. The steam gasification of biomass or lignocellulosic residues in a fluidized bed with a commercial catalyst as the gaseous oil steam reforming catalyst was investigated by Aznar et al.
The researchers found that the gaseous oil conversion reached However, they also pointed out that the severe coke deposition, which resulted in deactivation of the catalyst, was the main problem. To extend the lifetime and activity of Al 2 O 3 -supported catalysts, Li et al. The promoters, such as Fe, Ce, and some noble metal Pt and Ru were added to prevent Ni from sintering and maintain the activity of the catalyst. Moreover, the formation of the Ni—Fe alloy could justify the suppression of coke deposition and improvement of the activity and stability of the catalyst.
Fu et al. In the experiment of catalytic steam reforming of bio-oil derived from maize stalk, the highest hydrogen yield It can be explained by the fact that additional of Ce can improve the oxygen storage capacity, which is favorable for H 2 production as well as the resistance of coke formation. Except Al 2 O 3 , other metal oxides used as the support of the catalyst were also widely studied.
Ma et al. Park et al. Zeolite is a type of silicoaluminate with a crystalline structure, which is often used as a heterogeneous catalyst as a result of its regular pore structure, larger surface area, and surface acidity. Zeolites with multidimensional microporous structures show a key feature of shape selectivity.
Yan et al. Kong et al. BTEXN yields in coal gaseous oil increased to 4. He et al. The catalysts increased the amounts of light aromatics but decreased the amounts of aliphatics and oxygenated compounds. Moreover, pelletized HZSM-5 zeolite in a packed bed for the upgrade reaction was investigated, and the aromatic yield reached 3.
The yields of MAs reached 9. The yield of aromatics increased with the number of acid sites because a reactant molecule interacting with an acid site could block a nearby acid site. The volatiles were cracked and then underwent a series of deoxygenation reactions in the mesoporous shells. The results indicated that the metal species located on zeolite may stabilize hydrogen radicals from the dissociation of hydrocarbons, which further avoided the polycondensation reaction.
During the CFP process, larger pores and a high surface area allow for the production of more light aromatics. Meso-ZSM-5 showed the highest catalytic activity and a higher yield of aromatics. Generally, the resulting hierarchical zeolites could be obtained by demetallization of Al or Si through post-treatment, such acid leaching or base leaching.
Matias et al. Hierarchical HZSM-5 was prepared by the piperidine-assisted desilication method and performed in CFP of lignite to aromatic production. Later, Wang et al. The obtained sample was further modified with Ni. Their performance for CFP of cellulose was investigated and showed an excellent light aromatic yield. They found that the extra-framework Al species in HZSM-5 combined with SO 4 2— to form a superacidic surface sulfate complex exhibited an increase in the yield of light aromatics and a decrease in the yield of coke in comparison to that of original HZSM On the basis of the above results, it can be concluded that the zeolite pore size plays a dominating role in the mass transfer and diffusion of large intermediates into pores along with various reactions for the production of aromatics in the CFP process.
In particular, the conversion of OOSs to light hydrocarbons occurs within the framework of zeolite, largely depending upon shape selectivity in terms of the pore size and internal pore space. Hierarchical zeolites with meso- or macropores produce small molecules by cracking large OOSs and further conversion to aromatics.
During biomass pyrolysis, furan and its derivatives are highly active to polymerize and generate a significant amount of coke as a result of the presence of outside acid sites in the zeolite framework. The addition of metal oxide phases to zeolite results in a strong change in catalyst acidity, which displays a high selectivity of aromatics. The metal-modified and hierarchical zeolites must be evaluated comprehensively because hierarchical pores in addition to intrinsic microporosity eliminate diffusion restrictions for large molecules, promote the accessibility to active sites, and result in a higher lifetime of zeolite as a result of lower coke formation.
For the loading of metal species into zeolites, metal species suppress coke formation by tuning the density and activity of acidic sites to a certain extent. Although the above researchers involved the study of coke formation, the complex deactivation process was caused by many factors, such as the composition of feedstock, the properties of zeolites, etc.
Particularly, the narrow pores do not allow larger compounds access to channels of zeolites, which lead to coke formation on the surface via polymerization. Additionally, the stronger external acidity is also responsible for catalyst deactivation. Therefore, it is possible to reduce coke formation through comprehensive consideration on surface passivation of external acid sites and development of hierarchical pores.
As an important member in the heterogeneous catalyst system, zeolite can also be used as a good support modification with Ni to investigate the performance in biomass gasification and oil reforming. It is welcomed by researchers because of the high hydrothermal stability, excellent anti-coke ability, and easy regeneration. ZSM-5 was selected to be the support as a result of its suitable pore size and excellent shape-selectivity property.
Buchireddy et al. Kathiraser et al. The excellent activity is attributed to the smaller Ni—Fe alloy particles, which are less than 3 nm. This phenomenon finally led to more serious coke deposition. After that, they studied the influence of the Ni particle location in MCM for H 2 production during gasification of biomass in detail. The location of Ni particles was controlled by stirring for 30 min or 2 h. The scanning electron microscopy SEM results Figure 31 exhibited that most Ni particles were located inside the pores when stirred for 2 h.
As a result, the maximum yield of H 2 Char is a kind of non-metal material obtained by pyrolysis of coal and biomass with an abundant pore structure and surface functional groups. Semi-char is a promising catalyst support for catalytic reforming of oil materials into light gases and coke, , except that low cost and a simple recovery process qualify it as an excellent support in catalytic reforming of bio-oil. Char as a catalyst or support has the following characteristics: 1 The semi-char is rich in alkali metals and alkaline earth metals, which are dispersed in the semi-char as catalytic reactive metals.
The alkaline earth metal in the semi-char can promote the polymerization of hydrocarbons in the volatile phase to produce coke. In addition, char can adsorb oil compounds effectively. The application of activated char-based catalysts was also investigated to the upgrading process of pyrolysis volatiles.
This catalyst was accessible and could be used as a secondary catalyst for reduction of aromatics and gas production. In addition, through a comparison of char and AC support, Jin et al. However, biochar was explored in co-pyrolysis of coal and biomass to upgrade the coal tar and could provide catalytic active sites to crack the heavy fraction. The performance of activated char depends upon the particle size, surface area, and mineral content of the char Fe and Ni.
The catalyst was used in gasification of woody biomass in a two-stage fixed bed reactor, which achieved a H 2 yield of As a result of its high activity, Xiao et al. In view of the richness of organ oxygen species in lignite, it can be concluded reasonably that lignite possesses the excellent capacity of ion exchange with Ni as well as the ability of dispersing Ni in the coal matrix.
Thus, Wang et al. A lower Ni crystallite size 5. Moreover, the amount of carboxylate groups that were related to the ion-exchange capacity could be increased by the oxidation of lignite. Thus, Ren et al. The characterization results showed that the SSA and Ni loading witnessed a noticeable increase with a smaller Ni crystalline size, which was demonstrated by TEM images in Figure The gas yield obtained over various catalysts was presented in Figure Subsequently, they found that SL lignite treatment by HCl possessed a layered delocalized electronic structure.
Ni particles loaded on the support via the ion-exchange method were very small 0. As a result, the catalyst with a lower activation energy As reported, the raw lignite as a support was treated with HCl solution before ion exchanging with nickel solution. Co was loaded on the support by the impregnation method. It is well-known that some metals, such as K and Ca, are rich in biomass sample.
These metals are beneficial to enhance the decomposition of hydrocarbons and the WGS reaction as well as to reduce coke formation. Therefore, biochar was developed to be a catalyst or catalyst support. In consideration of this, Yao et al. On the basis of the positive effects of the alkaline earth metal surface area of the catalyst, Guo et al. The characterization results exhibited that the SSA was greatly increased from In the process of biomass gaseous oil catalytic reforming, RHC—KOH was the most active catalyst to promote H 2 production as well as gaseous oil elimination, rendering a H 2 yield of Moreover, the catalyst showed good stability by keeping the original porous structure even after 5 recycles.
Gai et al. The preparation conditions, such as the concentration of Ni solution and the calcination temperature, were carefully controlled. Importantly, some new thoughts about the design of future catalysts used for biomass gasification can be obtained. Further improvement of Ni-based catalysts is the focus of future research. Transition metals, noble metals, alkali metals, and alkaline earth metals can be doped into nickel-based catalysts to form alloys between metal Ni and other metals, enhancing the reductibility and electronic properties of catalysts.
In addition, in the preparation of catalysts, organic metal precursor solution and an appropriate increase of the specific surface area and pore size of the support are selected to improve the dispersity of the metal. As a result, the activity and stability of the catalyst are improved, enabling the catalytic cracking reaction to proceed under moderate conditions. At the same time, the selectivity of a specific component of syngas should be improved.
For instance, if high-purity hydrogen is to be produced for the purpose of biomass gasification, the catalyst design must be highly selective for hydrogen. If other metals are added to the Ni-based catalyst, the metal must have strong oxygen affinity to facilitate the WGS reaction. Moreover, the catalyst should be cheap, stable, and easily regenerated. The catalyst prepared with lignite char support and Ni active component via the ion-exchange method had been proven active in reforming of biomass-derived volatiles.
Although it is hard to regenerate, the low cost and natural production inside the reactor attract wide research. Its highly stable characteristic has also been proven by Xiao et al. The introduction of the promoter, such as transition metal, alkali metal, and alkaline earth metal, could markedly improve the activity and anti-coke deposition ability. However, the growth of the metal particle size and metal sintering are the problems to be solved. The next step should focus on the modification of the support, such as enlarging the specific surface area, decreasing the acidity, constructing a stable structure, and decreasing the size of the metal particle.
As reviewed above, Ni introduced by the ion-exchange method or one-step hydrothermal synthesis method could limit the size of the Ni particle 3—10 nm. Therefore, how to load Ni and promoter on the support using a similar method simultaneously to decrease the metal size and avoid the agglomeration deserves to be further studied. Recently, some other supports, such as hydrotalcite-like material, palygorskite, and ceramics, have been widely studied on a bench scale of gasification reforming.
Those catalysts with small and uniform metal nanoparticles and high dispersion possess superior activity and stability. The interaction between the metal and support is very strong, endowing the catalyst with a promising application potential. Jin et al. The mole ratio of Ni, Mg, and Al was controlled to , and the Ca loading is 0. The catalyst was named as N—Ca—Mg—Al with a surface area of H 2 production was improved after the addition of Ca as a result of the promoted WGS reaction, and the maximum H 2 yield was achieved when the content of Ca was 0.
Zou et al. Palygorskite is a kind of clay mineral, which is inexpensive and abundant in nature and possesses a distinct pore structure and high SSA. Baidya et al. The formation of the Ni—Fe alloy and the synergistic effect could improve the activity of the catalyst, while Mg and Ca as alkaline earth metals could help the dispersion of Ni and promote the steam reforming reaction.
The activity was kept for at least 48 h with no visible coke deposition. In short, these catalysts are very active and stable, but the complex preparation method and relatively higher cost hinder their commercial application. Fundamental Reaction Mechanisms. Pyrolysis technology has been the subject of research aiming at producing hydrocarbon fuels at a low cost.
For instance, Figures 36 and 37 show a schematic of FP of coal and biomass pine sawdust , which includes two steps: primary devolatilization reactions and subsequent secondary gas-phase reactions. The second step is decomposition reactions of the volatile products produced through the primary reactions. Both of them principally follow multiple, parallel radical, and rearrangement pathways in pyrolysis with or without a catalyst.
It is clear that the primary reactions must be controlled to further increase total volatiles, while the secondary gas-phase reactions are important to increase the yields of some specialized products. Many attempts have been made to study the CFP pathway that will promote the understanding of fundamental catalytic requirements for deoxygenation of complex volatiles at pyrolysis conditions.
Generally, the catalytic cracking of pyrolysis volatiles involves various reactions, such as protolytic cracking that breaks C—C bonds, hydrogen transfer, isomerization, and cyclization—aromatization, as well as deoxygenation reactions dehydration, decarboxylation, and decarbonylation. As shown in Figure 38 , in the first step, after a rapid thermal decomposition, lignite is converted into volatiles and gases.
Some of the heavy components, which mainly consist of macromolecular weight OOSs, are cracked to light organics. Other heavy components are polymerized on the catalyst surface to form coke. The second step is the diffusion of the light compounds into HZSM-5 pores.
These intermediate oxygenates undergo a series of reactions, such as decarbonylation, decarboxylation, dehydration, and oligomerization to form both MAs and C 2 —C 6 olefins. Moreover, the aliphatic structure combined with a covalent bond is regarded as the bridge and side chains in an aromatic ring or cross-linked to the macromolecular structure in the lignite structure. The pyrolysis fragments that interconnected aromatic rings to the oxygen atom can be regarded as intermediates, which further suffer from deoxygenation to aromatics.
Thus, lignite was partially pyrolyzed to substituted methoxyphenol 2 and 4 , hydroxyl-naphthaldehyde 5 , o -hydroxybenz-oxo-propionic acid 6 , and substituted ethanol 7. The fusion of HZSM-5 and metals is intended to produce a catalyst having both acidic and metallic sites. The metallic sites are favorable for hydrogenation and dehydrogenation reactions, while acidic sites accelerate the isomerization process.
Metal—Co centers were stabilized through a coordination bond between the O-donor ligand. The pyrolysis volatiles adsorbed on acid sites were hydrogenated by H species originating from H 2 or CH 4 dissociated on the metal site. In addition, the presence of metal—Co could provide more hydrogen available to fix the aromatic ring fragments and the small molecular hydrocarbons.
Appelt et al. The increase of alkenes can be explained by the cleavage of alkanes at the outer surface of the zeolite via protolytic mechanisms. Pyrolysis volatiles with an aliphatic structure liberated thermally from lignite can react over zeolite. However, only linear and methyl-branched hydrocarbons can pass through the small pores of the HZSM-5 framework.
Thus, it is not possible for the formation of alkanes via alkenes through a bimolecular process and hydride abstraction as a result of bulky intermediates. A carbenium ion is formed by the protonation of C—C bonds, and the intermediate is cleaved and desorbed as two smaller alkenes, mostly in the range of C 3 —C 6. To reveal the formation pathway of light aromatics, Lv et al. For PAs pyrene , they were cracked to light aromatics with two steps, such as the hydrogenation reaction and ring-opening reaction.
The former is to saturate one of the aromatic rings, and latter is to act as C—C bond breaking under an active center of zeolite. Correspondingly, some benzene series and phenolic compounds are produced by dealkylation and transalkylation of the methyl side chain. Dibenzothiophene undergoes two routes to form light aromatics.
One route is that one of the benzene rings undergoes hydrogenation and a ring-opening reaction to produce benzothiophene derivatives. Subsequently, these derivatives occur with hydrogenation and the ring-opening reaction of the thiophene ring to finally produce phenylmercaptan and B series.
The other route is that the breaking of the S—C bond under the action of the catalyst is stabilized by later hydrogen-rich free radicals to form biphenyl derivatives and fluorene. Then, these compounds continue to crack toward the formation of light aromatics. On the basis of analyses of model compounds, in Figure 42 , Lv et al.
They thought that the large pore size and pore volume of hierarchical Y-type zeolites could further facilitate the mass transfer of reactants in the channel and contact with the active center, thus promoting the formation of light aromatics. In addition, the adjusted acid sites are also an important factor in improving the catalytic activity. The composition of biomass is largely diverse. For instance, residues of plant origin are mainly composed of cellulose, hemicellulose, and lignin with varying percentages.
Hemicellulose consists of heterogeneous branched polysaccharides, whose sugar units are composed of five carbon atoms xylose and arabinose and six carbon atoms glucose, galactose, mannose, and rhamnose in Figure 43 b. Figure 43 c shows that lignin is a complex amorphous aromatic polymer with a three-dimensional network, linked by phenylpropane units. In the lignin structure, there are many polar groups and hydroxyl groups, allowing for the establishment of strong intra- and intermolecular hydrogen bonds.
In CFP over zeolites, cellulose, hemicellulose, and lignin as raw material are used to produce of high-value-added products, such as aromatics and phenol. In general, the conversion process assisted by a catalyst involves deoxygenation and a series of reactions including oligomerization, cyclization, and the hydrogen transfer reaction.
Some intermediate chemicals oxygenates, furans, etc. On the acid site of the catalyst, olefins as intermediates are further transformed into aromatics. In detail, cellulose produces anhydro sugars at the active site of the catalyst through acid-catalyzed dehydration. Finally, olefins are converted to aromatics, as demonstrated in Figure Hemicellulose in Figure 46 undergoes thermal degradation to double-hydrated xylose, which can easily diffuse in HZSM-5 pores and form smaller furan compounds without any further reactions with low molecular oxygenating species, such as acetic acid, formic acid, acetol, and formaldehyde.
Furanic species then undergo a series of catalytic decarbonylation and oligomerization reactions and finally produce aromatics monocyclic and polycyclic and olefins through a hydrocarbon pool mechanism. The potential route for the production of aromatics from lignin in Figure 47 shows that acidic sites of zeolite lead to the scission of C—O and C—C bonds among guaiacyl, syringyl, and p -hydroxylphenyl, which produces intermediates. These intermediates, being too comparatively larger to diffuse into a zeolite pore, depolymerize to coke formation on the zeolite surface, which is the main concern in CP.
Furthermore, the aromatic formation by hydrocarbon pool within a zeolite pore during CFP of biomass was proposed by many researchers. MAs could further react with oxygenates, such as furan, to form PAs, such as N, through the release of water and carbon monoxide. Moreover, alcoholic compounds could enter the hydrocarbon pool and form MAs and olefin by reacting with other hydrocarbons, although the exact nature of the hydrocarbon pool was still debatable.
In CFP of biomass, deoxygenation, cracking, hydrocarbon pool mechanism, aromatization, ketonization, and aldol condensation are the major reaction pathways in CFP, which depend upon the biomass, reaction mode, catalyst type, and other operating conditions. In view of the complex structure of real gaseous oil derived from biomass, the gaseous oil model compound is usually chosen to study the cracking mechanism during the process of biomass gasification.
The main reaction has been investigated and shown as eqs 22 — They carried out the T steam reforming over the catalyst and studied the reaction activation energy. The results revealed that a layered carbon-supported Ni catalyst, which possessed low activation energy They explained that the Ni plane of the catalyst may contribute greatly to its outstanding activity. They also proposed the apparent activation For a better understanding, Oemar et al.
The proposed reaction mechanism was shown in Figure On the basis of that, it can be concluded that the reaction of steam reforming of T takes place in five steps. First, water is dissociated on the support site to form absorbed H and OH. Absorbed OH is further dissociated to form absorbed H and O. As a result, absorbed O would occupy the oxygen vacancy, and absorbed H terminates with each other, followed by H 2 production. Second, the cracking of T occurs on the metal site with the formation of absorbed methyl and B.
Absorbed B further decomposes into absorbed species of acetaldehyde. Devi et al. They concluded that H 2 O and CO 2 could enhance the reaction; however, H 2 had an inhibitory effect. The possible reaction pathway for N decomposition is presented in Figure N decomposition is followed by a series of reactions that occur simultaneously. The cleavage of C—H and C—C bonds is the first step for the decomposition mechanism of the non-substituted aromatic compound.
As a result, rings of the aromatic compound are opened with the formation of lower aliphatics or aromatics. Then, these lower hydrocarbons react with each other consecutively to generate the permanent gases. Thus, it is reasonable to speculate that indene is the first stable production from the decomposition reaction, because only one carbon is subtracted.
In short, the investigation of the gaseous oil reforming mechanism using T and N as a model compound is easy. However, because those aromatics are the main components of real gaseous oil, the study can provide ideas for the cracking mechanism of the real gaseous oil from biomass gasification, which has complex components.
During the long-term reaction under steam, the investigation can also be an option to select a catalyst that possesses high activity and stability and strong steam resistance. As previously stated, the interests in CFP and gasification as the clean and efficient ways of coal and biomass utilization will continue to increase in the long term.
For economic and other reasons, the attention is increasingly focused on the CFP and gasification of low-rank coal and biomass. With the rapid development of pyrolysis technologies, the integrated process coupling with pyrolysis is expected to produce a greater economic benefit than a simple process. Its techno-economic performance determines whether it can ascend the full commercialization stage, whereas its industrial application still has a long way to go.
Herein, several major breakthroughs are cited in Table The reactor could hold the CP of 1 kg of moisture- and ash-free coal assisted by 8. Boateng et al. The bio-oil yield was lower than most results obtained from lab-scale CP experiments, which may be caused by product volatile loss and product collection difficulties. Incontrovertibly, successful demonstration of CRIPS provides the blueprints for pre-commercial design. Mante et al. They found that a higher carbon recovery was achieved for the total liquid products at the pilot scale However, the biocrude from the lab scale had a superior carbon content and lower oxygen.
Although the biocrude average yield was just In a recent experimental campaign where over kg of loblolly pine sawdust was fed in 15 h, David et al. Paasikallio at al. Interestingly, they observed a linear correlation between the catalyst alkali metal content K, Ca, Mg, and P and acidity.
Biomass alkali metals, which could deposit on the catalyst, resulted in its inactivation. For the coal pyrolysis technology, it has already achieved industrial application. Many researchers around the world have developed a variety of corresponding coal pyrolysis processes, such as the char oil energy development CODE process, liquid from coal LFC process, efficient co-production with coal flash partial hydropyrolysis technology ECOPRO process, and Da Gong DG process, with retorting technology using a solid heating carrier developed by the Dalian University of Technology.
Pyrolysis products consist of pyrolysis gas, char, and tar, which can achieve different application values. Coal pyrolysis gas can provide a partial heating value for coal pyrolysis, and char has good reducibility and is widely used in the steelmaking industry, while tar can produce more valuable aromatics by processing.
In comparison to pure coal pyrolysis, CFP of coal is more focused on the upgrading process of tar, so that it can yield valuable chemicals, although they have many similarities, such as an inert atmosphere, pyrolysis temperature, product distribution gas, char, and tar , etc. However, there are still few reports on the industrialization of CFP of coal.
The reason is that the orientation of the target product at two processes is completely different, which leads to different systems for coal pyrolysis and CFP of coal. In comparison to the CP of low-rank coal to prepare fine chemicals, biomass as a raw material is more attractive to researchers because of its renewability. However, the company did not get succeed in the end because of a low product yield.
If it could be moved smoothly into production, it will create great significance to promote the development of CFP of biomass technology. It is undeniable that the utilization of CFP of biomass to prepare chemicals and liquid fuels is the most promising way to solve the depletion of fossil fuels.
Syngas produced by biomass gasification has a wide commercial application. According to the description by Wang et al. The detailed information for industry application of syngas is presented in Table Industry Application of Syngas from Biomass Gasification. Rodrigues et al. Liquid fuels can be produced via the FT reaction eq Sasol in South Africa and Shell in Malaysia applied syngas in liquid fuel production commercially.
For power generation, the operation system usually contains a biomass gasifier, combustion engine, combustion turbine, steam turbine, or fuel cell. The gas turbine is considered as the most efficient electrical-generating system and the most suitable way to transfer heat to mechanical energy. The typical process of BIGCC application involves generating electricity by combustion of the syngas in a combustion turbine first, and then the hot exhaust passed through a heat recovery steam generator to produce steam, which is then sent to a steam turbine for additional electricity generated in a bottoming cycle.
Then, the content was further reduced to about ppm in the second stage. Finally, remaining CO can be totally removed by a pressure-swing adsorption system. Up to now, biomass gasification technology becomes more mature. However, the biggest challenge is also the cleaning of oil.
Although many catalysts have been developed for efficiently removing oil from syngas in the laboratory scale, there are not many reports for those catalyst used in industrial-scale experiments. Some design aiming at optimizing actual factors, such as the gas flow rate, temperature, pressure variation, catalyst broken, and impurities during the gasification process, in larger scale reactors should be considered.
Challenges and Future Research Perspectives. On the basis of the summary of the desired chemicals and H 2 -rich syngas via hydrotreatment, CFP, and gasification-reforming technologies, some challenges and limitations are highlighted for further improvement in the future.
Therefore, upgrading technologies should be exploited to deal with these issues and produce a drop-in replacement for downstream processing, while focusing on developing efficient and economical techniques. Each compound requires a different upgrading route, such as hydrotreatment, hydrocracking, reforming, etc. A primary upgrading route via functional catalysts acted mostly on a core unit of commercialized technologies and, therefore, is dependent upon the overall oil properties.
In fact, there is a significant research gap in process system design and engineering of emerging pyrolysis—catalysis technologies. The conceptual design based on the techno-economic performances of the industry-scale process should not only be promoted in parallel to the experimental programs, but also, more importantly, the results should be fed back to guide the experimental work to pay more attention to the steps of performance limitations or environmental damage.
Therefore, we particularly focus on the following aspects. For the gasification system, the fuel yield is relatively low, but oil formation can happen, which leads to equipment blockage and other operational difficulties. Thus, many kinds of biomasses are supposed to be applied after pretreatment densification, briquetting, and pelleting. Technology should be improved focusing on automatic screening and pretreatment of feedstock, to minimize cost and avoid the potential damage to the reactor.
In the future, it is also important to develop fast pyrolysis with multiple processing and catalytic steps in terms of optimizing and improving the polygeneration process through selecting the most suitable technology route, rationally matching the product production chain, increasing the added value of products, and improving thermal efficiency. Typically, improvement and development of a controllable secondary reaction reactor can inhibit the formation of heavy components and reduce the difficulty of pyrolysis oil separation.
Meanwhile, the quality and yield of oil and pyrolysis gas can be improved. Inevitably, the HDO process is accompanied by coke formation, resulting in catalyst deactivation. Therefore, for the hydrotreatment, an ideal catalytic system should contain metal oxides such as Al 2 O 3 , MoO x , zeolites, etc. In fact, most of the existing studies consider the catalyst design and process design in isolation. Many catalysts have been reported for catalyzing reforming of biomass volatiles actively and efficiently.
The design of a novel catalyst should focus on construction of a stable structure and introduction of multiple compositions. The stable structure can make it possible for the catalyst to be applied in a factory. Multicomponent catalysts will be more active for oil reforming as well as inhibiting coke deposition. However, the zeolite catalyst is easily deactivated as a result of the formation of a carbonaceous solid, limiting its commercial use. Many methods, such as modification with metals and solid acid, have been performed to improve the catalyst lifetime.
Full evaluation of hierarchical zeolites as FP catalysts may provide an opportunity for limiting coke deposition and improving the aromatic yield. In addition, catalyst deactivation is another subject that needs further investigation. Further experimentation is required to better represent the catalyst performance under realistic conditions. Use of the catalyst with a short life could significantly increase the cost of the process.
Therefore, future work is required to evaluate the catalyst life in a long test. In particular, deoxygenation may proceed by different pathways, such as dehydration, decarboxylation, and decarbonylation. The upgrading process of oil is mainly based on the promotion of different condensation reactions, which is also conducive to oligomerization of light components and depolymerization of larger biopolymer components.
However, it is worth noting that many processes occur simultaneously. Accordingly, labeling a specific transformation as a single type may be impossible as a result of the chemical complexity of real coal tar or bio-oil. Therefore, the preliminary optimization of the catalyst performance through model compound tests is of great significance in promoting specific reactions. Although mechanisms about steam reforming of light or heavy oil model compounds are nearly clear, there are few research studies on the mechanism for steam reforming of biomass volatiles or real coal tar or bio-oil.
Hence, making the mechanism for steam reforming of real coal tar or bio-oil clear is necessary, and that will be helpful for experiment parameter optimization and catalyst design. Herein, a comprehensive understanding of the kinetic mechanism enables us to find the operating conditions that facilitate the production of the desired products while avoiding the formation of unwanted compounds.
This work presented the state-of-the-art catalytic conversion coal and biomass volatiles. The essence of using volatiles is cracking and reforming it. Volatiles as the intermediate products of pyrolysis oil are rich in oxygenated compounds, such as carboxylic acids, phenols, and alcohols, leading to the major challenges for its direct use as a fuel as a result of the corrosiveness, viscosity, and low heating value.
In this review, high-quality products, including aromatics, H 2 -rich gas, and low-impurity-containing oil, are generated by CFP, gasification, and HDO, respectively. Catalytic upgrading of pyrolysis volatiles either in situ or ex situ over zeolite has exhibited the increased selectivity to aromatics and less oxygenated compounds in recent years. In comparison to the HDO process for aromatic production, the CFP process was performed under simple operating conditions, avoiding high pressure and H 2 consumption.
More than anything, the development and evaluation of new catalysts, such as zeolite, are being performed widely. It may also offer controlled acid—base properties, thus exerting a significant effect on tailoring the product distribution among aromatics and other important chemicals.
Incorporation of specific basic metal sites in hierarchical zeolites enhances deoxygenation, retaining the desired aromatic yields. Mesoporous zeolites are more feasible in CP by considering rapid deactivation of microporous zeolites and production of PAHs within pores of large zeolites. Catalytic gaseous oil reforming is proven as the most effective method to gasify at a very low temperature to achieve ultrahigh gasification efficiencies in the presence of gaseous oil deposition.
As the most common catalysts, Ni-based catalysts are active in most reactions but are easily deactivated as a result of the coke deposition. The activity and stability of Ni-based catalysts could be improved by some specific modification measures, such as changing support, alloying with secondary metals, rare earth metals, alkali metals, or noble metals, and improving the preparation method.
Meanwhile, further research is required to extend the lifetime of catalysts in oil conversion and its operating conditions. After modification, those catalysts are promising to commercial application. Sometimes, catalyst deactivation or poisoning depend upon the gaseous impurities, which are introduced along with the oil. Typically, the coke formation could be prevented by steam gasification and high-temperature gasification.
At last, in view of the complex composition of real gaseous oil, a model compound T and N is widely chosen to reveal the mechanism of oil cracking during biomass gasification. The authors declare no competing financial interest. Author Information. The catalytic valorization of lignin for the production of renewable chemicals. Zakzeski, Joseph; Bruijnincx, Pieter C.
American Chemical Society. A review on different approaches and strategies that were reported for catalytic lignin conversion with a focus on the manuf. Green and sustainable manufacture of chemicals from biomass: State of the art. Green Chem. Royal Society of Chemistry. A review. The various strategies for the valorisation of waste biomass to platform chems. The option involving the least changes to the status quo is the drop-in strategy of complete deoxygenation to petroleum hydrocarbons and further processing using existing technologies.
The alternative, redox economic approach, is direct conversion of, for example, carbohydrates to oxygenates by fermn. Examples of both approaches are described, e. Three possible routes for producing a bio-based equiv. Valorisation of waste protein could, in the future, form an important source of amino acids, such as l-glutamic acid and l-lysine, as platform chems.
Glycerol, the coproduct of biodiesel manuf. Lignin valorization: Improving lignin processing in the biorefinery. Science New York, N. Research and development activities directed toward commercial production of cellulosic ethanol have created the opportunity to dramatically increase the transformation of lignin to value-added products.
Here, we highlight recent advances in this lignin valorization effort. Discovery of genetic variants in native populations of bioenergy crops and direct manipulation of biosynthesis pathways have produced lignin feedstocks with favorable properties for recovery and downstream conversion.
Advances in analytical chemistry and computational modeling detail the structure of the modified lignin and direct bioengineering strategies for future targeted properties. Refinement of biomass pretreatment technologies has further facilitated lignin recovery, and this coupled with genetic engineering will enable new uses for this biopolymer, including low-cost carbon fibers, engineered plastics and thermoplastic elastomers, polymeric foams, fungible fuels, and commodity chemicals.
Elsevier Ltd. The max. A review on catalytic-pyrolysis of coal and biomass for value-added fuel and chemicals. During the process, org. Pyrolysis is also recognized as an efficient and low-cost process to produce a valuable liq. This liq. The use of catalyst is the most promising technique to improve the quality of the liq.
The present study presents a review on catalytic pyrolysis of carbon-based materials for prodn. In this review, three types of catalysts such as alk. Effect of process temp. Introduction to thermochemical processing of biomass into fuels, chemicals, and power. Baliban, Richard C. Elsevier B. Several technologies for synthesis gas syngas refining are introduced into a thermochem. The FT effluent can be i refined into gasoline, diesel, and kerosene or ii catalytically converted to gasoline and distillate over a ZSM-5 zeolite.
Methanol can be converted using ZSM-5 i directly to gasoline or to ii distillate via olefin intermediates. A mixed-integer nonlinear optimization model that includes simultaneous heat, power, and water integration is solved to global optimality to det. Twenty-four case studies consisting of different a liq.
Overview on recent developments on hydrogen energy: Production, catalysis, and sustainability. Catalytic fast pyrolysis: A review. Catalytic pyrolysis is a promising thermochem. Other important qualities include interpersonal skills, effective listening and speaking, the ability to handle stressful situations, and attention to detail. Most students finish the programs, offered at community colleges and technical schools , in about one year.
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