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News and Trendshttp://www.nature.com/nrg/journal/v9/n6/abs/nrg2336.html (full access to the paper may require paid subscription) A recent review by Professor Mariam Sticklen of the Michigan State University’s Department of Crop and Soil Sciences ( in the United States) describes the potentials of plant genetic engineering for decreasing the production cost of cellulose-ethanol. Cellulosic biomass is said to be the bioethanol feedstock of the future, due to the following characteristics: (1) relatively abundant renewable resource (i.e. feedstock supply can keep up with “staggering” global ethanol demand), (2) non-food resource (no adverse effect on food security), and (3) ability to grow in non-agricultural/marginal lands with lower agricultural inputs. However, the barrier to realizing large-scale, commercial processing of cellulosic biomass to ethanol, is the cost of production. Cellulose-ethanol is estimated to be about two to three times the cost of grain-ethanol. The cellulose-ethanol production process usually involves: (1) pretreatment of the biomass to remove lignin and render the cellulose accessible to cellulose-degrading enzymes (“cellulases”), (2) enzymatic degradation/conversion of the cellulose into simple sugars by cellulases, and (3) fermentation of the simple sugars to ethanol. The high cost of cellulose-ethanol production has been attributed to the high cost of enzymes, and the high cost of pretreatment (energy-intensive processes, usually requiring extreme temperature/pressure conditions). The review paper describes some strategies by which plant genetic engineering can be harnessed to produce “tailored, third-generation cellulosic feedstocks” that can help reduce the costs of pretreatment and cellulase enzymes. Among the plant modification strategies are: (1) production/accumulation of cellulases in sub-cellular components in the plant, and (2) reduction of lignin content/structure in the plant. Details of these strategies, status of research, as well as challenges for the future are also described. The paper appears in a recent issue of the journal, Nature (URL above)..
http://biopact.com/2008/05/biofuel-powered-microbial-fuel-cell.html The World Bank’s” Lighting Africa” competition prize was awarded to Lebônę Solutions (a collaborative group of students and scientists from Harvard University) for developing an innovative, low cost microbial fuel cell (MFC) technology with potential applications for developing countries. The microbial fuel cell can be viewed as a “biological battery”. It can generate electricity from organic rich materials (the “fuel”), such as soil, manure, or even food scraps, through the harnessing of energy metabolism of microorganisms. The combination of microbial metabolism of the organic matter and reactions that occur at the electrodes cause a flow of electricity through the circuit. In an interview posted by the off-grid website (URL above), Lebônę founder and managing partner, Hugo Van Vuuren, said that the MFC can “power an LED (light emitting diode) light, run a radio, or charge a mobile phone”. He also mentioned that Lebônę has embarked on an 18-month pilot project with 20 systems in Namibia so that the technology can be field tested, and refined. According to the Biopact website, “Lebônę's victory earns them $200,000 to roll out their biofuel consuming microbial fuel cell which will power lighting systems in sub-Saharan Africa”.. Energy Crops and Feedstocks for Biofuels Production
http://www.technologyreview.com/Energy/20828/ Verenium Corporation, a cellulose ethanol production technology company, has started operations of a cellulose ethanol production facility (annual production capacity of 1.4 million gallons) in Jennings, Louisiana. The facility is said to be the first demonstration scale cellulosic ethanol plant in the United States, and will test “variations on the company’s technology” in a continuous mode of operation. One of the goals of the facility is to cost-effectively produce cellulosic ethanol at $2 per gallon. The Technology Review website reports that the feedstock to be used for cellulose ethanol production will be “bagasse” (spent sugarcane stalks after juice extraction); the production process will include acid pretreatment (for lignin removal and for liberating the cellulose from the biomass), enzymatic treatment (to convert cellulose into simple sugars), and fermentation (to convert the simple sugars to ethanol). Construction of a fully commercial-scale production plant (20 million to 30 million gallons per year) is being planned next year. To date, there are still no full scale cellulose ethanol production plants in the United States, although some (with a few funded by the U.S. Department of Energy) are presently under construction..
http://www.d1plc.com/news.php?article=176 D1 Oils (D1), a UK-based biofuel technology company, will assess the cultivation performance of jatropha (a non-food based oilseed feedstock for biodiesel production) in “ultisol” soil types, through a series of field trials in Sumatra Island, Indonesia. The University of Bengkulu in South West Sumatra is the cooperating agency on the Indonesian side. “Ultisols” are generally acidic soils that are deficient in plant nutrients. Jatropha is usually a robust crop that can adapt to poor quality soils, but better oil yields for biodiesel production can be obtained with balanced addition of nutrients/fertilizers. Among the objectives of the field trials are to compare the growth and oil yields of Jatropha under different fertilizer treatments, and to obtain the optimum level of fertilizers that gives the best growth and oil yields. The Indonesian field trials form part of D1’s strategic global partnerships to gather information “to improve the cultivation of jatropha and alternative biofuel crops under different regions, climates and soil conditions”. More information of ultisols and jatropha Biofuels Processinghttp://www.public.iastate.edu/~nscentral/news/2008/may/fungus.shtml Scientists from Iowa State University and the University of Hawaii (both in the United States) have harnessed a fungus called Rhizopus microporus, to clean up the waste residue from dry-milling corn ethanol plants, and allow recycling with energy cost savings. The dry-grinding/milling process for corn ethanol process roughly involves the following steps: (1) grinding the corn kernels with the addition of water and enzymes (to convert the starches in corn into simple sugars), (2) fermentation of the sugars to ethanol by yeasts, (3) distillation of the fermentation broth to evaporate the ethanol, and (4) condensing the ethanol vapor into liquid ethanol. The liquid residue from distillation (called “thin stillage”) contains organic matter, solids and enzymes from the first step which can be recycled back to the process. However, because the solids and the organic matter in thin stillage can adversely affect ethanol fermentation, only 50% of the waste residue is recycled. The remaining portion is thermally processed and blended with distiller’s dried grains to produce a solid residue called “distiller’s dried grains with solubles”. In the new process, the Rhizopus microporus is added to the thin stillage and the organism cleans off the solids and organic matter. The “clean thin stillage” can then be completely recycled back into the system, without the need for the thermal processing step of “distillers dried grains with solubles”. The fungal biomass can also be processed into nutrient-rich animal feed supplement. According to Iowa State University Professor and Project Leader, Hans van Leeuwen, energy cost can be reduced by as much as one-third. The research won the 2008 Grand Prize for University Research, given by the American Academy of Environmental Engineers.. Biofuels Policy and Economics
http://www.iatp.org/iatp/press.cfm?refID=102707 The state of Minnesota in the United States recently passed legislation raising the biodiesel blend (in regular diesel) from the present 2% to 20% by the year 2015. (Minnesota was the first American state to mandate the use of biodiesel). The new legislation also includes the first ever state ban on the use of virgin palm oil for biodiesel production. This provision was made in order to assure that “Minnesota does not contribute to environmental destruction and rainforest clearing associated with palm oil production”. (Biodiesel production in the state is mainly soyabean-oil-based). Other provisions of the bill include the gradual use of alternative biodiesel feedstocks such as waste oil or algae (this will eventually lead to a shift toward the use of non-food based feedstocks), and an annual assessment of costs and benefits.. http://biopact.com/2008/05/brazil-sugarcane-bioenergy-bypasses.html The Biopact website shows data from Brazil’s annual National Energy Balance reports that indicate that almost half of Brazil's total energy (46.4%) now comes from renewable energy. Of the different types of renewable energy in the country, bioenergy is said to be the fastest growing resource. The combination of ethanol from sugarcane and energy from bagasse has become Brazil’s second primary energy source, surpassing hydroelectric energy. Although Brazil is also known for large hydroelectric power facilities, there are no prospects for the addition of new hydropower plants due to erratic rainfall, and the fact that most of the large rivers are dammed. An energy mix of 46.4% from renewables is relatively quite a good mix, compared to other OECD (Organization for Economic Cooperation and Development) countries, where only about 5.2% of their primary energy comes from renewable energy. The Biopact website further reports that “Brazil's sustainable energy mix might hold the future for many African countries”.. |
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