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Bioethanol–Moving Into the Marketplace Advanced Becoming Reality

Technology for producing transportation from is moving out of the laboratory and into the marketplace. In the past decade, advances in biotechnology have allowed us to reduce the projected cost of producing bioethanol from biomass materials other than and now used by nearly 25%. In the 1990s, the U.S. Department of Energy (DOE) National Bioethanol Program: ■ Developed new, more versatile, microorganisms capable of squeezing more from biomass THE PROGRAM MISSION: Warren Gretz, NREL/PIX 02268 ■ Gained a greater understanding of how the individual technology components work together To develop cost-effective, environ- in an integrated process mentally friendly technologies for ■ Supported the private sector’s initiatives to production of alternative transport- commercialize bioethanol technology ation and fuel additives from plant biomass As we enter the 21st century, we are seeing federal invest- The Biofuels Program is managed by the ment in research beginning to pay dividends in the market- Office of Fuels Development (OFD) at place. Meanwhile, the DOE Bioethanol Program is building the U.S. Department of Energy (DOE). on these successes. Our research program targets process Biofuels research and development Warren Gretz, NREL/PIX 05790 improvements that will ultimately allow bioethanol to includes work on a range of renewable compete head to head with as a fuel supply for liquid fuels, and covers the whole spec- the U.S. transportation sector. Our strategy is simple. We trum of technology development from basic science to commercial deployment. will ride the growing wave of biotechnology advances to DOE’s Bioethanol Program is by far the build efficient bioprocesses for ethanol production. largest of several fuel development efforts managed by OFD under the auspices of the Biofuels Program.

The National Bioethanol road, new energy like switchgrass. Today, farmers leave millions of tons of residue on the Warren Gretz, NREL/PIX 03246 Program ground after harvesting corn. The responsible What is biomass? Biomass in- Today, fuel ethanol in the United States is made collection and use of this residue—known as cludes the full range of plant from corn , a biopolymer of that corn —offers a huge opportunity for and plant-derived materials. is readily broken down to sugars.The goal of expanding the supply of ethanol from its Starches and sugars from the National Bioethanol Program is to develop current level of 1.6 billion per year which ethanol are currently technology which can produce ethanol from (2000) to more than 10 billion gallons per year. made are just a very small the sugars in and hemicellulose, two As demand expands beyond this level, newly portion of available biomass. of the main components of the fibrous material developed energy crops will come into play. The great bulk of biomass that makes up the bulk of most plants. This consists of cellulose, hemicel- Bioethanol Conversion Technology opens up a wide range of feedstock materials lulose, and lignin. Advanced Two key steps are at the heart of the DOE for bioethanol production to supplement bioethanol technology allows Bioethanol Program’s research and develop- current production from starch. fuel ethanol production from ment activities for bioethanol conversion the cellulose and hemicellu- Biomass Feedstock Development technology: lose, greatly expanding the DOE researchers are developing new sources 1. . This is a chemical reaction renewable and sustainable of biomass for bioethanol production. These that releases sugars, which are normally resource base available for include the residues left over after harvesting linked together in complex chains. In early fuel ethanol production. of existing food crops and, further down the biomass conversion processes, acids were used to accomplish this. Recent research stand how these organisms handled these has focused on catalysts called sugars, and to create new organisms capable “cellulases” that can attack these chains of efficient conversion of all the sugars found in more efficiently, leading to very high biomass. With the advent of new tools in the yields of fermentable sugars. emerging field of biotechnology, researchers at DOE labs and at universities across the 2. . Microorganisms that country, have succeeded in producing several Min Zhang, NREL/PIX 06812 ferment sugars to ethanol include new strains of and that exhibit and bacteria. Research has focused on Zymomonas recognized varying degrees of ability to ferment the full expanding the range and efficiency of the by scientific peers spectrum of available sugars to ethanol. The organisms used to convert to ethanol. advances made in the 1990s are now the 1995—R&D 100 Award starting point for entrepreneurs interested in 1995—Science magazine realizing a new bioethanol industry. Existing publication, “Metabolic ethanol producers are also looking to these Engineering of a Pentose new organisms as a pathway for improving Metabolism Pathway in their own bottom line as well. Ethanologenic Zymomonas mobilis” 1996—U.S. Patent #5,514,583 Hydrolysis Fermentation “Recombinant Zymomonas for pentose fermentation” Bioethanol recycles 1998—U.S. Patent #5,712,133 “Pentose fermentation by recombinant Zymomonas” Breakthroughs in Fermentation 1998—U.S. Patent #5,726,053 “Recombinant Zymomonas Technology in the Past Decade for pentose fermentation” Lead to Commercialization of 1998—U.S. Patent #5,843,760 Biomass Conversion Technology “Single Zymomonas mobilis strain for xylose and arabi- Common sense suggests that we need to convert nose fermentation” every bit of biomass into fuels and coproducts. For ethanol production, this means using all the available sugars. For most of this century, Warren Gretz, NREL/PIX 00947 researchers assumed that many of the sugars At the Bioethanol Program’s one-ton-per-day Process contained in biomass were not fermentable— Development Unit, bioethanol developers can test those contained in hemicellulose. This meant proposed processes under industrial conditions with- that as much as 25% of the sugars in biomass out having to build their own pilot plants. were out of bounds as far as ethanol produc- tion was concerned. In the 1970s and 80s, microbiologists discovered microbes that could ferment these sugars, albeit slowly and inefficiently. The race was now “on” to under-

ADVANCED BIOETHANOL TECHNOLOGY— PROVIDING MULTIPLE OPTIONS

The race to create new microbes capable of fermenting Zymomonas, a naturally efficient ethanol-producing the full range of sugars found in biomass has followed bacterium, and added the capability for utilizing multi- several successful pathways. Dr. Lonnie Ingram at the ple sugars (see “Zymomonas recognized by scientific University of Florida started with an E. coli bacterium peers,” above left). capable of metabolizing multiple sugars and added the DOE also helped support Purdue’s Dr. Nancy Ho, who ability to make ethanol—a feat for which he received started with the “industrial workhorse” for ethanol U.S. Patent #5,000,000 in 1990. His work was sponsored production—the yeast Saccharomyces—and added by the Biofuels Program and others. the capability for utilizing multiple sugars. Taking an approach that complements Dr. Ingram’s All three organisms are now being tested by industrial E. coli, other DOE researchers started with the bacterium partners for use in bioethanol production. A Decade of Generating our core Research and Development program with activities focused on near-term deployment Engineering “Know-How” opportunities. Our goal is to plant the seeds today for the technology we are developing Along the continuum of technology develop- for tomorrow’s renewable fuel industry. ment from basic science research to commer- cialization, process engineering data bridges Giving a boost to today’s fuel ethanol the gap between scientific inventions in the industry Today’s ethanol producers are lab and commercial production facilities. The looking for ways to push their yields as high Bioethanol Program, over the past ten years, has as possible. They are turning their attention increased the engineering knowledge base by to corn fiber—the shell of the kernel—as collecting rigorous material and energy balance a source of additional sugars for ethanol data on integrated bioethanol processes. Today, production. But, corn fiber, like other forms Warren Gretz, NREL/PIX 03479 we have greater confidence about projected of biomass, contains sugars that are not process performance and cost, and a far more fermentable by today’s Current U.S. ethanol realistic understanding of the engineering organisms. The National Corn Growers Asso- producers use only the issues remaining to be solved. This kind of ciation and the Corn Refiners Association are starch in the corn kernels. information is critical to entrepreneurs and working with DOE researchers to tailor new The fiber left from that financiers looking at multimillion-dollar invest- microbes that can ferment these specific processing, however, plus ments in bioethanol technology. sugars. This is work that builds directly off the cobs, husks, and stalks the Bioethanol Program’s successes of the past all contain sugars that can decade. Customized organisms developed in also be made into ethanol. Support for Today’s Industry this cooperative project will be available to the and Tomorrow’s Pioneers member companies of these two important industry trade groups. The Department of Energy’s Bioethanol Pro- gram supports a portfolio of activities that is Supporting industry pioneers for a balanced across the spectrum of technology new bioethanol industry Several com- development. To this end, we supplement panies are now pursuing niche opportunities

CONCENTRATED ACID TECHNOLOGY Masada Resource Group. Masada is a company that views bioethanol as one of several tools in its aresenal for managing waste and operations. They are planning on constructing a bioethanol plant in New York State, where solid waste disposal costs are very high. The plant will convert the biomass portion of municipal solid waste into fuel grade ethanol. DOE researchers have worked with Masada to collect engineering data on one of the key process steps—the separation and recycling of from the sugar stream prior to fermentation. Municipal solid waste—an untapped resource for bioethanol. ➧ DILUTE ACID TECHNOLOGY Dynamic Graphics/ 066009 BC International. BCI is building a facility that will initially produce 20 million gallons per year of ethanol from —the residue left over after production. BCI will utilize an existing ethanol plant located in Jennings, Louisiana. At the heart of BCI’s process is the recombinant E. coli originally patented in 1990.

DOE researchers have worked with BCI to collect critical process engineering data. ➧ Groundbreaking ceremony for BCI’s bagasse-to-ethanol plant in Jennings, Louisiana. Blane David Paul/PIX 06544 Fungal production of cellulase. ➧ ENZYME TECHNOLOGY Iogen. Iogen is a Canadian enzyme producer who recently entered into a joint venture with PetroCanada to demon- strate the use of cellulase in the production of bioethanol. The Bioethanol Program is supporting research at the University of Wisconsin and the University of Toronto to evaluate the use of a yeast strain and DOE’s recombi- nant Zymomonas in their process. Iogen is targeting agricultural residues such as and for their initial commercial demonstration. Warren Gretz, NREL/PIX 03287 Genencor/Novozyme. Because enzyme technology offers such great promise for ethanol production— if the cost of cellulase enzymes can be reduced—the Bioethanol program has contracted with two of the largest industrial enzyme producers to develop low-cost cellulases. Both Genencor International and Novozymes Biotech expect to be able to dramatically reduce cellulase cost over the next three years;

this would greatly improve the economics of bioethanol technology. ➧ Computer animation of cellulase enzyme attached to cellulose. Mike Himmel, NREL/PIX 05014 Acid Glucose-to- Hemicellulose for introducing bioethanol technology in the 1950 U.S. Each of these companies has identified hydrolysis ethanol sugars to disposal one of several variations of the process for converting biomass into ethanol. Two of the Enzyme Enzyme Glucose-to- Hemicellulose 1970 processes involve the use of sulfuric acid, production hydrolysis ethanol sugars to disposal in either concentrated or dilute form, to hydrolyze the cellulose and hemicellulose, while the third introduces the use of enzymes Enzyme Enzyme hydrolysis Hemicellulose 1980 called cellulases to hydrolyze the most production Glucose-to-ethanol sugars-to-ethanol challenging of the biopolymers—cellulose.

Enzyme Enzyme hydrolysis production Glucose-to-ethanol Bioprocessing—a strategy Today Hemicellulose sugars- of adding, improving to-ethanol and combining biological process steps Enzyme production Enzyme hydrolysis A strategy that reflects past and Glucose-to-ethanol Tomorrow? future accomplishment Today we talk Hemicellulose sugars- to-ethanol about our strategy for future technology Biological step improvements in terms of “bioprocessing,” Non-biological step but, in fact, this is not a new approach. Bioprocessing captures the approach that we have taken over the past few decades, as suggested by the illustration above. Dilute 1999 study projected that cost at $1.16 per acid hydrolysis reached the limits of its capa- . This cost assumes access to moderately bilities after several decades of research that priced feedstocks (at around $25 per dry led to the construction of a plant during World ton), and reflects a combination of the best War II and further refinements in the 1950s. results reported by various research groups At that time, the biological steps were limited in industry and in the private sector. The fuel to the conversion of glucose to ethanol by ethanol market currently supports a conventional industrial yeast. Early in the of anywhere from $1.00 to $1.40 per gallon. 1970s, research began on the use of cellulase Though the high capital investment and enzymes to hydrolyze cellulose—an approach higher risk of deploying new technology are that offered higher yields and elimination still hurdles to be overcome, it is clear that of unwanted side reactions. The 1980s saw the new bioethanol technology is poised for dramatic improvements in enzyme perform- commercial introduction. ance, and the first efforts to consolidate bio- Produced for the logical hydrolysis and glucose fermentation. In 2000 the fuel ethanol market accounted for U.S. Department of Energy (DOE) by the National Today, we have taken bioprocessing of ethanol 1.6 billion gallons per year in sales (2.0 billion Laboratory, a DOE national from biomass one step further by genetically capacity). This market is now constrained— laboratory DOE/GO-102001-1436 engineering microbes capable of fermenting because of cost—to the use of ethanol as a Revised August 2001 hemicellulosic sugars as well as cellulosic blending agent in gasoline, with only limited sugars. What will bioprocessing mean for sales of “”—85% ethanol fuel. As technology Printed with a renewable-source tomorrow’s technology? The exact form is costs drop, bioethanol will add sales of any- ink on paper containing at least 50% wastepaper, including 20% post- not clear. We are attacking the technology on where from 6 to 9 billion gallons year. With the consumer waste. several fronts—by applying new biotech tools blend market saturated at this level of ethanol Neither the United States government nor any agency thereof, nor any of to improve cellulase enzymes and continuing sales, we will then set our sites on the bulk fuel their employees, makes any warranty, to enhance the fermenting organisms. express or implied, or assumes any market—competing head-to-head with gasoline legal liability or responsibility for the at ethanol costs of around $0.60 per gallon. ■ accuracy, completeness, or usefulness So, what does all this of any information, apparatus, product, The Marketplace or process disclosed, or represents that technology improvement mean for the market- For more information contact: its use would not infringe privately owned rights. Reference herein to any place? Before the introduction of microbes Robert Wooley, Biofuels Technology Manager, specific commercial product, process, or service by trade name, trademark, capable of handling multiple sugars, ethanol National Renewable Energy Laboratory manufacturer, or otherwise does not from biomass was projected to cost about [email protected] necessarily constitute or imply its endorsement, recommendation, or $1.58 per gallon for the enzyme process. A (303) 384-6825 favoring by the United States govern- ment or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.