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Scientists from Purdue University (United States) recently conducted a study comparing the performance of B20 (20% blend) soybean-based biodiesel and petroleum-based "Ultra Low Sulfur (ULS) Diesel" on a fleet of 20 trucks. The trucks were paired by make, model, mileage, and drive cycles, with ten trucks operated with the B20 biodiesel and ten trucks operated with ULS diesel. The performance indices for comparison (measured over a 12-month period) were: fuel consumption, idle time, truck speed, engine load, and engine speed. Fuel properties such as cetane number, energy content, density, kinematic viscosity, and lubricity were also measured for both fuels. Their results showed that "there [was] almost no statistical performance difference in semitrailer trucks using B20, a 20-percent blend of biodiesel, and No. 2 ultra-low sulfur diesel, the current standard". According to the Purdue University News article, "the only statistical difference related to the B20 was that it lowered the oil viscosity between maintenance intervals in engines slightly more than the ultra-low sulfur diesel". Nevertheless, the oil is said to still possess "sufficient viscosity so as not to damage engine parts". The study is published in the journal, Applied Engineering in Agriculture (URL above)..  

One of the bottlenecks in the production of cellulose ethanol from lignocellulosic biomass is the saccharification step, where the cellulose from the biomass is broken down into simple sugars which can then be fermented to ethanol. Cellulose is a long chain of glucose molecules which are connected together by what is known as "glycosidic bonds". Enzymes which have "glycosyl hydrolase" (GHase) activities are said to be potentially useful for degradation of cellulosic biomass for biofuel production. Enzymes with high biomass degradation activities are often "discovered" by microbial screening programs, involving the cultivation of microorganisms in the laboratory. An emerging field, known as "metagenomics", stands as an alternative strategy for the discovery of biomass degradation enzymes without the need for direct cultivation of the microorganism.

Using molecular biology techniques, DNA from microbial communities (for example, in soil samples), is obtained and investigated for genes that encode enzymes for biomass degradation. A recent article by Luen-Luen Li and associates from the Brookhaven National Laboratory (United States) reviews "metagenomic approaches to mining complex microbial communities (comprising both non-cultivable and cultivable microorganisms) for biofuel production". One of their review findings mentioned that metagenomes (genetic material from an environmental sample) from microbial communities derived from termite guts displayed "more putative glycosyl hydrolase (GHase) homologues compared to other samples, such as human oral microflora. The complete review can be accessed in the online open journal, Biotechology for Biofuels (URL above).

Related information on metagenomics  

Energy Crops and Feedstocks for Biofuels Production  (may require paid subscription for complete access)

Dutch scientists from the Department of Water Engineering Management and the Laboratory of Thermal Engineering at the University of Twente (Netherlands) recently published a report which explored the "Water Footprint" (WF) of bioenergy produced from crops that are commonly used by many countries. The report defined the "Water Footprint" (WF) to be the "volume of freshwater used for [bioenergy] production at the place where it was actually produced". The units of the WF used in the study were in terms of cubic meters of water per Giga-joule of bioenergy. Bioenergy may be in the form of electricity, heat and biofuels (ethanol/biodiesel, all biomass-derived). The crops mentioned in the study were: barley, cassava, maize, potato, rapeseed, rice, rye, sorghum, soybean, sugar beet, sugar cane, wheat, and jatropha. These are some of the findings: (1) the WF of electricity production from biomass (bioelectricity) is smaller than the WF of biofuel production (by a factor of 2); (2) bioethanol production has a smaller WF compared to biodiesel production, (3) jatropha has a large WF at 600 cubic meters per Giga-joule, (4) the lowest WF for bioethanol production can be obtained from the following crops: sugar beet, potato, sugarcane. The complete report is published in a recent issue of the Proceedings of the National Academy of Sciences (URL above)..

Biofuels Processing  

Scientists from the Agrotechnology and Food Sciences Group of Wageningen University (Netherlands) report the production of hydrogen from the perennial grass, Miscanthus giganteus. Hydrogen is considered one of the clean biofuels of the future, and research is actively being pursued to make the technology cost-effective. In their study, the researchers subjected Miscanthus grass to alkali pretreatment to liberate the celluloses and hemicelluloses in the biomass from the tight lignin wrapping, followed by enzymatic saccharification to convert  liberated cellulose/hemicellulose molecules into simple sugars. The sugars were converted to hydrogen gas by thermophilic anaerobic fermentation (70oC to 80oC) by a mixed culture of Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana. Results showed that the microorganisms "simultaneously and completely utlized the major sugars (pentoses, hexoses) in the hydrolyzate". The hydrogen production yields were 74% to 85% of the theoretical. The complete results of the study can be accessed at the Biotechnology for Biofuels (online open access journal) website (URL above).

Biofuels Policy and Economics 

A recent feature article in the Environmental Science and Technology Journal (URL above) raises issues concerning the impacts of increased biofuel production on water security. The challenge of "ensuring inexpensive and clean water" under the Millenium Development Goals of the United Nations is seen to be intensified by the increasing demand for biomass-derived fuels because (1) the cultivation of biofuel crops will require large quantities of water, and (2) "water pollution is exacerbated by agricultural drainage containing fertilizers, pesticides, and sediment". The other end of the spectrum for increased biofuels production is the significant potential to ease dependence on foreign oil and improve trade balance(s) while mitigating air pollution and reducing fossil carbon emissions to the atmosphere. The report, which is authored by scientists from Rice University, Clarkson University, and Missouri University of Science and Technology (United States) mentions that the water requirement associated with driving on biofuels can be significant. To minimize the "water footprint" of biofuels, a bioenergy crop should ideally be drought-tolerant, with high biomass yields and can be grown on little irrigation water. The authors also urge that "biofuels should be supported by rainfall, instead of irrigation". The full report can be accessed at the website of the Environmental Science and Technology Journal (URL above)..

Researchers from the Environment and Production Technology Division of the International Food Policy Research Institute (IFPRI) report the use of an "integrated hydrologic-economic basin model" to study the impacts of enforced water pollution standards on fertirrigation in a biofuel feedstock (sugarcane) plantation, located in a sub-basin of the Pirapama River (Brazil). The model was also used to assess "sustainable water allocation in the basin." Fertirrigation can be considered as a "joint process of irrigation and fertilization, using the irrigation water to carry and distribute the chemical or organic fertilizer over the crops". This is reportedly an important practice in the light of increased demand for sugarcane as the primary feedstock for ethanol production in Brazil. According the report, "incorporating water quality aspects into water allocation decisions leads to a substantial reduction in application of vinasse to sugarcane fields. To enforce water quality restrictions, the shadow price for maintaining water in the reservoir could be used as a pollution tax for fertirrigated areas, which are currently not subject to pollution charges. The full report can be accessed at the IFPRI website (URL above).

Related information on fertirrigation:

A meeting on Biodiesel Development held at the World Agroforestry Center in Nairobi on June 9, 2009 has identified the Jatropha plant as the best candidate for production of biodiesel in Kenya. Eng. Kuloba of the Kenya Industrial Research and Development Institute (KIRDI) revealed that the Jatropha seeds may contain up to 35% oil in composition. This is in addition to the plant's ability to survive even in the harshest arid and semi-arid areas, which means it doesn't have to compete for space with food crops.

Jatropha is also already in existence in many parts of the country, and all that needs to be done is to educate farmers on its commercial value. As Dr. Githunguri of the Kenya Agriculture Research Institute (KARI) puts  it, "The plant already exists in many farms, being used as a hedge or even as clothes lines. Efforts have to be focused on educating and empowering the farmers so they can harness the full commercial potential of the plant." He also explained that in addition to being a source of fuel, the plant can serve as a source of revenue to farmers and thus help in reducing poverty in many parts of the country that are otherwise unsuitable for farming of food crops. On its part, the Ministry of Energy has set various targets and objectives which include a 5% blend (B5) of biodiesel with diesel by 2012. This would help the country save billions in energy costs.

For details and for more information on biodiesel development in Kenya contact Ms. Faith Odongo, Chief Renewable Energy Officer, Ministry of Energy at

China recently opened its first bioenergy research center in the city of Nanning, the capital of the country's southern Guangxi Zhuang autonomous region. According to the Chinese Academy of Sciences press release, "the research center is set up based on the national guidance on energy and grain security, and will look to cassava, sugar cane, sweet sorghum as the main sources for new energy development". The location of the bioenergy research center in Guanxi seems to be a good choice, because the region has a "rich reserve of cassava, sugar cane, which takes up more than 65 percent of the nation's total". The first cassava-ethanol project plant (200,000 tonnes per year) is also situated in Beihai City, Guanxi. Support for research expertise and facilities will be provided by the Guangxi Academy of Sciences..