[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
UGA-led team engineers bacterium for the direct conversion of unpretreated biomass to ethanol
June 03, 2014
A team led by Dr. Janet Westpheling at the University of Georgia has engineered the thermophilic, anaerobic, cellulolytic bacterium Caldicellulosiruptor bescii, which in the wild efficiently uses un-pretreated biomass—to produce ethanol from biomass without pre-treatment of the feedstock. A paper on the work is published in Proceedings of the National Academy of Sciences (PNAS).
In January, Dr. Westpheling and her colleagues reported in the journal Science their discovery that an enzyme (the cellulase CelA) from C. besciia can digest cellulose almost twice as fast as Cel7A, the current leading component cellulase enzyme on the market. (Earlier post.)
Study finds removing corn residue for biofuel production can decrease soil organic carbon and increase CO2 emissions; may miss mandated 60% GHG reduction
April 21, 2014
|Contribution of modeled CO2 emissions from SOC to the life cycle of biofuel from corn residue. Error bars are ± one standard deviation. Liska et al. Click to enlarge.|
Using corn crop residue to make ethanol and other biofuels reduces soil carbon and under some conditions can generate more greenhouse gases than gasoline, according to a major, multi-year study by a University of Nebraska-Lincoln team of researchers published in the journal Nature Climate Change. The findings cast doubt on whether biofuels produced from corn residue can be used to meet federal mandates for cellulosic biofuels to reduce greenhouse gas emissions 60% compared to gasoline.
The study, led by assistant professor Adam Liska, was funded through a three-year, $500,000-grant from the US Department of Energy, and used carbon dioxide measurements taken from 2001 to 2010 to validate a soil carbon model that was built using data from 36 field studies across North America, Europe, Africa and Asia. Using USDA soil maps and crop yields, they extrapolated potential carbon dioxide emissions across 580 million 30-meter by 30-meter geospatial cells in Corn Belt states.
Navigant Research forecasts 58% growth in global biofuels consumption by 2022; biodiesel and drop-in fuels gain market share
February 05, 2014
In a new report, “Biofuels for Transportation Markets”, Navigant Research forecasts that global demand for biofuels in the road transportation sector will grow from representing almost 6% of the liquid fuels market in 2013 to roughly 8% by 2022. Of that 8%, 8% will consist of advanced drop-in fuels, according to the research firm. Navigant forecasts that global biofuels consumption in the road transportation sector will grow from more than 32.4 billion gallons per year (BGPY) in 2013 to more than 51.1 BGPY in 2022—an increase of 58%.
Overall, Navigant forecasts that global retail sales of all liquid fuels for the road transportation sector will grow from more than $2.6 trillion in 2013 to more than $4.5 trillion in 2022 (73% growth).
DEINOVE produces ethanol at 9% titer with its optimized Deinococcus bacteria
January 16, 2014
DEINOVE, a technology company that designs, develops and markets a new generation of industrial processes based on optimized Deinococci bacteria, has produced ethanol at a titer of 9% via its fermentation of biomass sugars in 20L pre-industrial fermentors. In September 2012, the company had reported that its optimized strain of Deinococcus generated ethanol from wheat-based biomass with a titer of 3%. (Earlier post.)
The 9% content v/v (volume/volume)—equal to 7.2% wt/v (weight/volume)—exceeds the 5% alcohol content wt/v considered to be the threshold for industrial exploitation of a process for 2nd generation biofuels, the company said. The obtained performance is gradually approaching the maximum theoretical yield, the company added. The use of Deinoccoccus offers several benefits:
Sandia study finds meeting RFS2 requirements unlikely without stronger enforcement mechanism; the importance of drop-in biofuels
January 06, 2014
Even if well-known technology, infrastructure, economic and political challenges in meeting the biofuel requirements of the RFS2 mandate are overcome, it is “highly unlikely” that the light-duty vehicle parc will be capable of consuming the RFS2 (Renewable Fuel Standard) mandated volumes of biofuels, according to a new analysis by a team from Sandia National Laboratory.
The Sandia researchers showed that the key to meeting the RFS2 targets is the fuel price differential between E85 fuel and conventional gasoline (low ethanol blends), so that E85 owners refuel with E85 whenever possible. In other words, RFS2 will be satisfied if gasoline becomes significantly more expensive than E85 on a per energy basis. This is, however, the opposite of historic pricing trends, and suggests that policy intervention of a stronger enforcement mechanism will be required to meet RFS2 targets by creating market conditions necessary for greater biofuel consumption.
NREL/UGA study finds microbial enzyme digests cellulose ~2x fast as current leading commercial cellulase; implications for biofuels cost
January 04, 2014
Researchers at the Energy Department’s National Renewable Energy Laboratory (NREL) and the University of Georgia have discovered that an enzyme from a microorganism first found in the Valley of Geysers on the Kamchatka Peninsula in Russia in 1990 can digest cellulose almost twice as fast as Cel7A, the current leading component cellulase enzyme on the market.
The high-performance enzyme CelA was discovered 15 years ago, but until this recent work, all that was known about this complex protein was its general architecture and that it had the ability to degrade cellulose. If it continues to perform well in larger tests, it could help drive down the price of making lignocellulosic fuels, from ethanol to other biofuels that can be dropped into existing infrastructure. A paper reporting this finding appears in the journal Science.
Field trials with genetically modified poplars shows potential for efficient conversion to sugars but with impact on biomass yield
December 31, 2013
|Ethanol yield (g/L) for the Belgian and French field trials. Van Acker et al. Click to enlarge.|
The results of field trials with genetically modified poplar trees in Belgium and France shows that the wood of the modified poplar trees—down-regulated for cinnamoyl-CoA reductase (CCR), an enzyme in the lignin biosynthetic pathway—improved saccharification yield—i.e., it can be more efficiently converted into sugars for producing bio-based products such as bio-plastics and bio-ethanol.
However, the study, published as an open access paper in Proceedings of the National Academy of Sciences (PNAS), also found that strong down-regulation of CCR also affected biomass yield. The team, from Belgium, France and the US, led by researchers from VIB and Ghent University, concluded that CCR down-regulation may become a successful strategy to improve biomass processing if the yield penalty can be overcome.
ICCT suggests minor changes to Fed tax policy to cut higher investment risk of 2nd-gen biofuels and advance the industry
December 22, 2013
Minor changes to an existing Federal tax incentive for second-generation biofuels (i.e., biofuel made from cellulose, algae, duckweed, or cyanobacteria) could mitigate the current elevated risk of investing in the industry that is retarding its advance, according to a new paper by a team from the International Council on Clean Transportation (ICCT) and Johns Hopkins University. Some of the ICCT recommendations are mirrored in the recently released Baucus draft proposal for tax reform (earlier post), notes Dr. Chris Malins of the ICCT, one of the study’s co-authors.
Previous studies have attempted to explain the slow commercialization of cellulosic and algal biofuels qualitatively, however few have presented financial analysis across the sector, the authors observe. Using publicly available financial data, they applied investment analysis tools (the capital assets pricing model, CAPM) that are generally not applied to this space in order to develop a more rigorous understanding of the investment risk in the industry.
DSM and DONG Inbicon show cellulosic bio-ethanol fermentation on industrial scale with 40% higher yield
December 09, 2013
Royal DSM, together with DONG Energy (Denmark), has demonstrated the combined fermentation of C6 and C5 sugars from wheat straw on an industrial scale. The combined fermentation results in a 40% increase in ethanol yield per ton of straw, which can result in significant cost cuts in the production of bio-ethanol from cellulosic feedstock.
The demonstration took place in DONG Energy’s Inbicon demonstration plant in Kalundborg (Denmark), the longest running demonstration facility for cellulosic bio-ethanol production in the world. (Earlier post.) The facility was reconstructed in 2013 in order to be able to conduct mixed fermentation of C6 and C5 sugars. In a two-month fermentation test mixed C6 and C5 fermentation using DSM’s advanced yeast was found to yield 40% more ethanol per ton of straw than traditional C6 fermentation.
Study shows bamboo ethanol in China technically and economically feasible, cost-competitive with gasoline
December 01, 2013
Bamboo, the composition of which is highly similar to energy grasses used for biofuel production such as switchgrass, is an interesting potential feedstock for advanced bioethanol production in China due to its natural abundance, rapid growth, perennial nature and low management requirements.
Now, researchers at Imperial College London have shown that bioethanol production from bamboo in China is both technically and economically feasible, as well as cost-competitive with gasoline. An open access paper on their study is published in Biotechnology for Biofuels.
Raízen breaks ground on Iogen cellulosic ethanol facility in Brazil
November 29, 2013
Iogen Corporation announced that Brazilian ethanol giant Raízen Energia Participações S/A has started construction of a commercial biomass-to-ethanol facility using Iogen Energy’s advanced cellulosic biofuel technology. (Iogen Energy is a joint venture between Raízen and Iogen Corporation. Earlier post.)
The $100-million plant, to be located adjacent to Raízen’s Costa Pinto sugar cane mill in Piracicaba, São Paulo, will produce 40 million liters (10.6 million gallons US) of cellulosic ethanol a year from sugarcane bagasse and straw. Plant start-up is anticipated in the fourth quarter of 2014.
EPA proposes reduction in cellulosic biofuel and total renewable fuel standards for 2014
November 15, 2013
The US Environmental Protection Agency (EPA) is proposing a reduction in the cellulosic biofuel and total renewable fuel standards (RFS) for 2014. Once the proposal is published in the Federal Register, it will be open to a 60-day public comment period.
Specifically, EPA is proposing a total renewable fuel target of 15.21 billion gallons; the final 2013 overall volumes and standards require 16.55 billion gallons; the original target as specified in the Clean Air Act is 18.15 billion gallons. (Earlier post.) EPA is setting the troublesome cellulosic biofuel target at 17 million gallons—significantly lower than the Clean Air Act (CAA) target of 1.75 billion gallons—but an increase from the 6.0 million gallons specified for 2013. This reflects EPA’s current estimate of the amount of cellulosic biofuel that will actually be produced in 2014, but EPA will consider public comments before setting the final cellulosic standard.
Univ. of Illinois team argues that renewable fuel standard needs to be modified, not repealed
October 16, 2013
A policy analysis by two University of Illinois researchers argues that Congress should minimally modify, not repeal, the Renewable Fuel Standard (RFS). In the study, law professor Jay P. Kesan and Timothy A. Slating, a regulatory associate with the Energy Biosciences Institute, argue that RFS mandates ought to be adjusted to reflect current and predicted biofuel commercialization realities; that its biofuel categories be expanded to encompass all emerging biofuel technologies; and that its biomass sourcing constraints be relaxed.
In the paper, to be published in the NYU Environmental Law Journal, Kesan and Slating contend that the RFS can serve as a “model policy instrument” for the federal support of all types of socially beneficial renewable energy technologies.
Yeast engineered to co-consume xylose and acetic acid boosts cellulosic ethanol yield by 10%
October 08, 2013
Commercial production of cellulosic biofuel via fermentation pathways has been hampered by inefficient fermentation of xylose and the toxicity of acetic acid, which constitute substantial portions of cellulosic biomass. Now, researchers from the University of Illinois at Urbana-Champaign and UC Berkeley have engineered yeast to convert cellulosic sugars and toxic levels of acetate together into ethanol under anaerobic conditions.
The innovation, reported in a paper published in Nature Communications, increases ethanol yield from lignocellulosic sources by about 10%. The results, the researchers suggest, demonstrate a breakthrough in making efficient use of carbon compounds in cellulosic biomass and also present an innovative strategy for metabolic engineering through which an undesirable redox state can be exploited to drive desirable reactions—even improving productivity and yield.
Study finds HTL algal biofuels offer 50-70% lifecycle CO2 reduction compared to petroleum fuels; EROI and GHG comparable to or better than other biofuels
September 20, 2013
A new life cycle analysis by a team led by researchers at the University of Virginia has concluded that biofuel produced from algae via hydrothermal liquefaction (HTL) can reduce life cycle CO2 emissions by 50 to 70% compared to petroleum fuels, and also has energy burdens and GHG (greenhouse gas) emission profiles that are comparable to or better than conventional biofuels, cellulosic ethanol and soybean biodiesel.
HTL algae-derived gasoline has a considerably lower GHG footprint and a better EROI relative to conventional ethanol made from corn on a per MJ basis, the team found. The data suggest that a shift to algae-derived gasoline could have immediate climate benefits even using existing technologies, the authors noted. In addition, given expected technological improvements, the benefits of algae-derived gasoline will likely improve.
Novozymes and Raízen to collaborate on cellulosic ethanol in Brazil
September 18, 2013
Novozymes has entered into a collaboration agreement with Brazil’s largest sugarcane crusher, Raízen Energia S/A (the $12-billion joint venture between Shell and Cosan founded in 2011). (Earlier post.) As part of the agreement, Novozymes will supply enzyme technology to Raízen’s first commercial-scale cellulosic ethanol plant in Brazil, scheduled to be operational by end 2014.
The plant will be a bolt-on facility to Raízen’s Costa Pinto sugarcane mill in the state of São Paulo and will have the capacity to produce 40 million liters (10.5 million gallons US) of cellulosic ethanol a year from sugarcane bagasse and straw. The agreement also provides for Novozymes to supply enzyme technology to Raízen’s second cellulosic ethanol plant, should such a plant be constructed.
JBEI team develops one-pot, wash-free process for pretreatment and saccharification of switchgrass; avenues for driving down biofuel cost
August 14, 2013
|Conventional separate pretreatment and saccharification of biofuel feedstock (a) entails water and waste disposal that the new one-pot system (b) eliminates. (Image courtesy of Joint BioEnergy Institute). Click to enlarge.|
Researchers with the US Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) report the first demonstration of a one-pot, wash-free process that combines ionic liquid (IL) pretreatment and enzymatic saccharification into a single vessel using a thermostable IL-tolerant bacterial consortium comprising several species of thermophiles (microbes that thrive at extremely high temperatures and alkaline conditions).
Using this one-pot system, they liberated 81.2% glucose and 87.4% xylose (monomers and oligomers) at 72 h processing at 70 °C with an enzyme loading of 5.75 mg g−1 of biomass at 10% [C2mim][OAc]. Glucose and xylose were selectively separated by liquid–liquid extraction with over 90% efficiency, thus eliminating extensive water washing as a unit operation.
EPA sets 2013 percentages for Renewable Fuel Standard; anticipating adjustments to 2014 volume requirements
August 06, 2013
The US Environmental Protection Agency (EPA) finalized the 2013 percentage standards for four fuel categories that are part of the Renewable Fuel Standard (RFS) program. The final 2013 overall volumes and standards require 16.55 billion gallons of renewable fuels to be blended into the US fuel supply (a 9.74% blend).
The 2013 standard specifically requires: biomass-based diesel (1.28 billion gallons; 1.13%); advanced biofuels (2.75 billion gallons; 1.62%); and cellulosic biofuels (6.00 million gallons; 0.004%). These standards reflect EPA’s updated production projections. All volumes are ethanol-equivalent, except for biomass-based diesel which is actual volume.
CCST report: an integral role for next-gen biofuels in meeting California GHG targets requires advanced biofuels and demand reduction
June 11, 2013
Next-generation biofuels can reduce greenhouse gas emissions of transportation to meet California’s target greenhouse gas (GHG) reduction goal, but deep replacement of fossil fuels through implementation of low-carbon lignocellulosic ethanol and advanced biomass derived hydrocarbons (drop-in biofuels) and reduction in demand is required, according to a new report from the California Council on Science and Technology (CCST).
The study, “California Energy Future: the Potential for Biofuels,” co-authored by Energy Biosciences Institute (EBI) scientists Heather Youngs and Chris Somerville, is the seventh and final report in its California’s Energy Future (CEF) project. The CEF project seeks ways the State could meet the mandated reductions of greenhouse gas (GHG) emissions to 80% below 1990 levels by 2050, exploring possible energy strategies for California through in-depth examinations of different technology scenarios.