Tag Archives: biofuels
New Advance in Biofuel Production
May 9, 2013 — Advanced biofuels — liquid fuels synthesized from the sugars in cellulosic biomass — offer a clean, green and renewable alternative to gasoline, diesel and jet fuels. Bringing the costs of producing these advanced biofuels down to competitive levels with petrofuels, however, is a major challenge. Researchers at the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI), a bioenergy research center led by Berkeley Lab, have taken another step towards meeting this challenge with the development of a new technique for pre-treating cellulosic biomass with ionic liquids — salts that are liquids rather than crystals at room temperature. This new technique requires none of the expensive enzymes used in previous ionic liquid pretreatments, and makes it easier to recover fuel sugars and recycle the ionic liquid. “Most of our ionic liquid efforts at JBEI have focused on using enzymes to liberate fermentable sugars from lignocellulosic biomass after pretreatment, but with this new enzyme-free approach we use an acid as the catalyst for hydrolyzing biomass polysaccharides into a solution containing fermentable sugars,” says Blake Simmons, a chemical engineer who heads JBEI’s Deconstruction Division and was the leader of this research. “We’re then able to separate the pretreatment solution into two phases, a sugar-rich water phase for recovery and a lignin-rich ionic liquid phase for recycling. As an added bonus, our new pretreatment technique uses a lot less water than previous pretreatments.” Simmons is the corresponding author of a paper describing this research that has been published in the journal Biotechnology for Biofuels. With the burning of fossil fuels continuing to add 9 billion metric tons of excess carbon dioxide to the atmosphere each year, the need for carbon neutral, cost-competitive renewable alternative fuels has never been greater. Advanced biofuels, produced from the microbial fermentation of sugars in lignocellulosic biomass, could displace gasoline, diesel and jet fuel on a gallon-for-gallon basis and be directly dropped into today’s engines and infrastructures without impacting performance. If done correctly, the use of advanced biofuels would not add excess carbon to the atmosphere. Environmentally benign ionic liquids are used as green chemistry substitutes for volatile organic solvents. While showing great potential as a biomass pretreatment for dissolving lignocellulose and helping to hydrolyze the resulting aqueous solution into fuel sugars, the best of these ionic liquids so far have required the use of expensive enzymes. Recent studies have shown that acid catalysts, such as hydrochloric or Brønsted, can effectively replace enzyme-based hydrolysis, but the subsequent separation of sugars and ionic liquids becomes a difficult and expensive problem can require the use of significant amounts of water. Guided by molecular dynamics simulations carried out at DOE’s National Energy Research Scientific Computing Center (NERSC), Simmons and his colleagues at JBEI solved this problem by deploying the ionic liquid imidazolium chloride in tandem with an acid catalyst. “Imidazolium is the most effective known ionic liquid for breaking down lignocellulose and the chloride anion is amenable with the acid catalyst,” Simmons says. “The combination makes it easy to extract fermentable sugars that have been liberated from biomass and also easy to recover the ionic liquid for recycling. By eliminating the need for enzymes and decreasing the water consumption requirements of more traditional ionic liquid pretreatments we should be able to reduce the costs of sugar production from lignocellulose.” Complete separation of the pretreatment solution into sugar-rich water and lignin-rich ionic liquid phases was attained with the addition to the solution of sodium hydroxide. The optimized sodium hydroxide concentration for both phase separation and sugar extraction was 15-percent, resulting in the recovery of maximum yields of 54-percent glucose and 88-percent xylose. The JBEI researchers believe these sugar yields can be increased by optimizing the process conditions and using more advanced methods of phase separation and sugar recovery. “After optimizing the process conditions, our next step will be to scale the process up to 100 liters,” Simmons says. “For that work we will use the facilities at the Advanced Biofuels Process Demonstration Unit.” This research was supported by the DOE Office of Science, which also supports NERSC. Continue reading
More Plant Sugars, More Biofuels: Funding Continues For J.B.E.I. Work
Monday, 15 April 2013 JBEI’s Henrik Scheller (left) and Dominque Loque, shown here with Arabidopsis plants, are engineering plant cell walls to make the sugars within more accessible. (Photo by Roy Kaltschmidt, Berkeley Lab) The Joint BioEnergy Institute has received a five-year renewal of funding from the United States Department of Energy. Under the terms of the renewal, J.B.E.I. will be funded by up to $25 million annually through 2018. The J.B.E.I. is a Bioenergy Research Center created by the D.O.E. to conduct research on the development of advanced, next-generation biofuel. Originally established in 2008, it was backed by a $125 million grant for the first five-year period. The J.B.E.I. is led by the Lawrence Berkeley National Laboratory but also includes researchers from the Sandia National Laboratory, the University of California campuses of Berkeley and Davis, the Carnegie Institution for Science, the Pacific Northwest National Laboratory, and the Lawrence Livermore National Laboratory. J.B.E.I. research, for the past five years, has focused on developing advanced biofuels from lignocellulosic biomass, which uses grasses and other non-food crops and agricultural waste to create alternatives to fossil fuels. Using synthetic biology techniques, the J.B.E.I. researchers seek to engineer plants to enable easy extraction of plant sugars from biomass and to increase the sugar yields of energy crops. Softer walls, less sugar A recent example of the work done in J.B.E.I. would be a genetically engineered Arabidopsis plant that produces less xylan in its cell walls (see related story ) and another with less lignin then the natural plant with more extractable sugars for the biofuel process. “Through the tools of synthetic biology, we have engineered healthy plants whose lignocellulosic biomass can more easily be broken down into simple sugars for biofuels,” said Dominique Loque, who directs the cell wall engineering program for J.B.E.I.’s Feedstocks Division. Lignocellulosic biomass is one of the most abundant organic materials found on Earth. It has been used as animal feed and in the creation of paper. Now scientists are focused on using lignocelluloses as a source of sugars for advanced biofuels. Lignocellulose makes up the plants cell walls. In order to get to the fermentable sugars, the lignocelluloses need to be broken down, a process that can be difficult, expensive and time consuming. Researchers have been searching for a way to reduce lignin, a major polymer in plant cell walls, to enable easier sugar extraction. Most efforts have however resulted in sever biomass yield reduction or a loss of integrity in the plant’s vessels, a key tissue for water and nutrient distribution. What Mr. Loque and his colleagues did was rewire the regulation of lignin biosynthesis and create an artificial positive feedback loop to enhance secondary cell wall biosynthesis in specific tissue. “When we applied our APFL to Arabidopsis plants engineered so that lignin biosynthesis is disconnected from the fiber secondary cell wall regulatory network, we maintained the integrity of the vessels and were able to produce healthy plants with reduced lignin and enhanced polysaccharide deposition in the cell walls,” said Mr. Loque. The researchers believe that this technique can also be implemented to other plant species for biofuel crops with less lignin and more sugar. Enhancing national security, increasing green jobs Aside from the J.B.E.I., the Energy Department also funds two other Bioenergy Research Centers, the BioEnergy Research Center led by Oak Ridge National Laboratory and the Great Lakes Bioenergy Research Center led by the University of Wisconsin-Madison. According to Energy Secretary Steven Chu, the establishment and support of these centers by the administration is intended to help the biofuels industry move forward to decrease the country’s dependence on foreign oil, as well as generate new clean energy jobs. As with the J.B.E.I., both the B.E.S.C. and the G.L.B.R.C. will be funded worth $25 million for the next five years. Emphasis during these years will be on bringing the new methods and discoveries in the centers to maturity to enable their transition into the marketplace. – K.R. Jabuena Continue reading
Rising Ethanol Prices Another Blow to Viability of Biofuels
April 15, 2013 By Robert Potts Ongoing drought in Midwest America is driving up the price of ethanol and threatening the long term sustainability of the biofuels industry. Heavy water shortages across the “corn belt,” the major maize producing region of the United States, have damaged the supply of corn bushels, driving up the price of ethanol fuel. This is another blow to the biofuels industry at a time when it is facing sustained criticism from politicians and environmental groups worldwide. Many people claim that ethanol is not a long term alternative to fossil fuels due to associated rises in global food prices and changes in land use. This latest blow, however, even casts doubt over ethanol’s ability to provide a short term fuel solution. According to the USDA , record-high corn prices are likely to continue throughout 2013, rising up to 19 per cent higher than the last two years; in some cases, farmers in Missouri have seen their annual crops fall to up to 5.5 percent of their normal yield. Nearly 10 per cent of the US’s ethanol plants have ceased production in the past year, unable to cope with rising resource costs and shrinking demand. Government intervention and bloated supply Only five years ago, ethanol was hoped to be the savior to the long term depletion of fossil fuels. As a wholly renewable source of energy, the fuel can be blended with traditional gasoline and sold at gas stations across America. For the last 10 years the US government has mandated that gasoline must contain at least 10 per cent biofuel. Ethanol production was subsequently supported with a tax credit of 45 cents per gallon, although this deal expired at the end of 2011, making it a lucrative trade for farmers and producers. As a result, the number of ethanol plants has grown to hundreds in US states like Missouri, bringing huge economic gains to small towns. Farmers have been able to find a new market for their corn crops, while ethanol producers reacted by building new plants and creating thousands of new jobs. However, recent economic conditions have since exposed weaknesses in the government’s biofuel policy. The original 10 per cent ethanol mandate assumed that overall demand for gasoline would grow over time. However, the current recession has seen overall demand for gasoline, and ethanol, shrink, exposing a bloated ethanol industry overly reliant on state subsidies. Over supply of ethanol has now created thousands of barrels of ethanol which are sitting in storage plants across the Midwest unused; these barrels will remain idle until there is enough gasoline available to blend with them. The current supply side crisis has therefore served to compound pre-existing structural issues within the industry. “It’s a more sombre mood,” said Todd Sneller, the administrator of the Nebraska Ethanol Board. “The growth opportunity that existed some years ago is still out there in theory, but the reality is that it’s going to take an awful lot of time, money and political battles to realise that opportunity.” “Blend wall” creating demand side difficulties With most cars and service stations only able to cope with a fuel blend of 10 per cent ethanol, known as the “blend wall”, demand restrictions clearly exist; the hope that demand will rise for higher percentage ethanol blends has not yet materialised. “Flex-fuel” vehicles, which can operate on 85 per cent ethanol, are also yet to be taken up by the mass market, and technological advancement in electric vehicles will only add further pressure to the industry’s long term competitiveness. In the EU, discussions are currently under way to limit the production of first generation biofuels, like ethanol, to half of Europe’s renewable fuel target, as a result of concerns over their long term environmental sustainability. Underdeveloped second generation fuels With ethanol under pressure, many hope that in the longer term, developments in second generation biofuels, synthesised from non-food sources, will provide a more viable alternative. Although cost advances are being achieved in these ‘cellulosic’ biofuels, productive capacity is still very small in comparison to ethanol. Whether these crops can be commercialized without requiring similarly high levels of water and changes in land use is open to much debate. Whether the biofuels industry can dust off this recent blow also remains unknown. Idle plants and unused barrels could clearly be short term side effects of changes in the economic cycle, but could also be a sign of longer term decline: “Is that going to be temporary or permanent? It’s hard to say,” said Eric Lee, Citibank commodities expert. However, with producers hoping to produce an extra three-tenths of a gallon of ethanol per bushel of corn, technological development could yet save an industry merely bruised from a particularly tough year. Robert Potts is owner of RPM Fuels, providers of tanks and pumps to the fuel industry. RPM Fuels supply oil tanks as well as specific equipment for biofuels and bio diesel. Continue reading
