Historic Moment for Second Generation Biofuels
(From SEJournal, Summer 2009)
The US and Canadian biofuels industry is struggling to pull through an historic shift to second generation production feedstocks and production technologies.
Pressure is coming, in part, from low carbon fuel standards passed by the California Air Resources Board in April, and also from the need for some return on federal development funding injected into the industry since 2007.
At least eight major cellulosic biofuels plants are in production or under construction in the US and Canada.
So, it’s now or never for cellulosic biofuels — the “fuel of the future” for almost a century, and long seen as the only source of renewable fuel that could replace petroleum.
“We think, ultimately, cellulosic materials are the only materials where you can produce enough under environmentally sustainable conditions,” said Chris Somerville, director of the Energy Biosciences Institute at the University of California at Berkeley at the 2008 Society of Environmental Journalists conference.
Somerville is restating an opinion expressed by Henry Ford, Isaac Asimov, and even, 90 years ago, by the scientist who founded the Cellulose Chemistry division of the American Chemical Society – Harold Hibbert.
“It looks as if in the rather near future, this country will be under the necessity of paying out vast sums yearly in order to obtain supplies of crude oil from Mexico, Russia and Persia,” Hibbert said in a 1921 journal article. “It is believed, however, that the chemist is capable of solving this difficult problem…. (and) it would seem that cellulose in one form or another is capable of filling that role.”
A few years later, Henry Ford told the New York Times: “The fuel of the future is going to come from fruit like that sumac out by the road, or from apples, weeds, sawdust — almost anything.”
Science writers kept track of the issue, and in 1940, science writer William L. Laurence wrote about a Jewish scientist who fled the Nazis. Prof. Ernst Berl, by then working at Carnegie Institute, developed a pressurizing process for reducing cellulose from all kinds of plant materials to either liquid or solid fuels. His work, Laurence said, “assures mankind of an illimitable supply of the prime movers of the wheels of civilization for all time, after natural deposits have been exhausted.”
Another WWII era development was the discovery of cellulose – eating microbes in the remote jungles of the Pacific. Soldiers called it “jungle rot,” but Elwyn T. Reese and others in the US Army labs realized that the enzyme from the fungus was turning cotton into sugar by splitting the strong chemical bond holding cellulose molecule together.
This process, a key to making paper and celluloid film, had traditionally involved highly polluting acid and pressure treatments. Still, the enzyme approach seemed to have promise, especially after the first oil shock of the 1970s.
Natick scientists told Congressional committees that they could produce fuel from cellulose at low cost, and without affecting food supplies, but the oil industry fought the idea, saying the fuel would cause all kinds of technical problems.
Research continued in hundreds of university and government labs, and thousands of unrecognized scientists took small steps, isolating, characterizing and testing the complex chemical structures of plants, which includes not only cellulose (linear sets of six-carbon glucose molecules in strong bond) but also five carbon sugars (hemicellulose) and glue-like substances (lignin).
Science fiction writer Isaac Asimov found it fascinating, and wrote about cellulose chemistry in some of his novels and articles. “Cellulose can be broken down into glucose molecules,” Asimov noted in a 1986 article, “and the glucose solution can be fermented into alcohol… (and) used as a liquid fuel.” The advantage? “Cellulose is self-renewing if we are carful to conserve our forests, so the fuel we get from it could last indefinitely, whereas oil from the ground must be completely used up eventually.” Asimov found it hard to resist the science fiction notion that that mutant microbes might get outside their tanks and dissolve the forests.
Waste wood and switchgrass and other energy crops have0 the potential to create 1.3 billion tons of terrestrial biomass, and replace at least 30 percent of US petroleum, according to a 2005 Oak Ridge National Labs study. More recent studies at Auburn and the University of Illinois have shown potentially greater yields with miscanthus and other low-input crops.
The billion ton study changed the federal government’s approach to energy, but there are concerns about the use of Conservation Reserve Program land, about increased forestry, and other impacts from intensified biomass harvesting.
Research today on switchgrass and miscanthus provides stunning evidence of high potential – over 1,000 gallons of fuel per acre, as opposed to hundreds per acre with corn. Among researchers working on energy crops are Ken Vogel at the University of Nebraska, David Bransby of Auburn (AL), Stephen Long at the University of Illinois, John Sheehan of the National Renewable Energy Laboratory (NREL), and Somerville of Berkeley.
In the end, a broader resource base for fuel production would include, Somerville said, energy plants that would have the benefit of producing oils and fuel-like substances that would be very close to gasoline and diesel, and consequently need little energy to refine.
Two interesting efforts to broaden the resource base using marine cellulose (kelp) involve work in University of Costa Rica and the Scottish Association for Marine Sciences.
Costa Rican marine cellulose research
Scottish marine cellulose research
Billion Ton Study (2005)
Cellulose biofuels industry information
Department of Energy Cellulose Biomass resources
CARB estimated that cellulosic process came out with the lowest carbon intensity, measured by C02 equivalent per megaJoule – expressed as gCO2e/MJ. (MegaJoules are about 948 Btus, or about one tenth of a gallon of ethanol).
CARB – ARGONNE CARBON INTENSITY CALCULATIONS
• 20.40 gCO2e/MJ cellulose ethanol from farmed trees
• 22.20 gCO2e/MJ cellulose ethanol from waste wood
• 73.40 gCO2e/MJ sugarcane ethanol. ( * includes 46 gCO2e/MJ for land change )
• 96 gCOe/MJ gasoline from California
• 99.4 gCO2e/MJ corn ethanol ( * includes 30 gCO2e/MJ for land change )
( * The land change penalty accounts for situations where new cropland is brought into production somewhere else to offset corn or sugarcane grown for ethanol.)
Although grain producers reacted with dismay to the new standards, which will effectively keep corn ethanol out of California, CARB believes that the new standard will eventually lead to the development of 1.5 billion gallons of cellulosic biofuel, 25 new plants and 3,000 new job. http://www.arb.ca.gov/fuels/lcfs/lcfs.htm
// ENZYME process – Combinations of mild acid and pressure pre-treat the plant material, then enzymes break cellulose down into glucose, and then ferment the glucose into ethanol or other chemicals.
• POET – 20,000 gal/yr – Scotland, SD. Enzyme process. Operating, will lead to 25 million gallons per year commercial facility in Emmetsburg, Iowa, making ethanol from corn cobs and stalks in tandem with a standard grain ethanol plant,
• ABENGOA Bioenergy – Hugoton, KS. Enzyme process. Wheat straw Starting construction in 2010, in production by 2011.
• IOGEN – Ottowa, Canada – Enzyme process. One of the earliest firms to work on the cellulosic enzyme process, Iogen declined a partial US-funded deal and is working with a start-up plant in Canada.
• DUPONT DANISCO — Vonore, TN – Under construction, plant will use switchgrass and enzyme processing.
• VERENIUM – Jennings, LA. — 1.4 million gallon demonstration-scale plant / waste biomass sugarcane
// ADVANCED ENZYME process – Along with enzyme breakdown of cellulose into glucose, a chain of enzymes can produce a variety of products, not just ethanol.
• MASCOMA – Rome, NY – Began in February 2009 with capacity of 200,000 gallons of cellulose ethanol, gasoline or other chemicals from wood chips, grasses, corn and sugar cane residues. An affiliate is developing a commercial-scale facility in Kinross, Michigan.
// ACID process – Strong sulfuric acid is added to dried biomass, heated and then separated under pressure. This is very similar to the way cellulose is separated for paper.
• BLUEFIRE Ethanol – Irvine, CA. Acid process. Garbage, wood waste, ag residues – Still hung up on siting. http://www.bluefireethanol.com/
Synthesis gas – Heat and pressure are applied and biomass is turned into biogas — hydrogen and carbon dioxide streams — that are then re-combined in the presence of catalysts to create different kinds of fuels or chemicals.
• RANGE BIOFUELS – Soperton, GA. Synthesis gas (syngas) using heat, pressure and steam, and catalytic treatments. Under construction. First 20 million gallon phase by March 2010 http://www.rangefuels.com/our-plants.html
// OTHER projects still at the lab and scale-up stage include:
Colusa Biomass Energy Corporation, Sacramento, CA Waste rice straw
Fulcrum BioEnergy Reno, NV Municipal solid waste
Gulf Coast Energy , Livingston AL Wood waste
KL Energy Corp. Upton, WY Wood waste.
SunOpta Little Falls, MN Wood chips
US Envirofuels Highlands County, FL Sweet sorghum
Global Energy Holdings Co., Atlanta GA Citrus peels