|
||||||
 |
||||||
 |
||||||
|
||||||
|
||||||
News and Trends
(full access to article may require payment or subscription) Scientists from the University of California Berkeley and the University of Maryland School of Medicine (both in the United States) report the existence of a consortium of "three hyperthermophilic archaea enriched from a continental geothermal source by growth at 90°C on crystalline cellulose". Archaea are a class of organisms recently recognized as a distinct "domain" of life on earth (the other domains include Eukaryotes and Bacteria). Many organisms under Archaea are known to thrive in extreme environments (hyperthermophilic and/or hypersaline environments); these organisms have generated research excitement due to their potential to produce new types of enzymes for innovative or "robust" applications. The researchers also mentioned that this is the first report of Archaea being able to "deconstruct" lignocellulose at near-boiling temperatures (90 degrees Celsius). This discovery of a hyperthermophilic lignocellulose-deconstructing organism opens new and exciting possibilities for lowering the cost of pretreating lignocellulosic biomass for biofuel-ethanol production. The researchers report that a "robust" cellulase enzyme has been identified from the archaeal enrichment. Cellulases are enzymes which breakdown cellulose in plant biomass into component sugars which can be fermented to ethanol. These enzymes are presently active only at mesophilic temperatures (30 degrees Celsius to 50 degrees Celscius). The newly-identified hyperthermophilic cellulase has been observed to have an optimal activity at 109 °C, a half-life of 5 hours at 100 °C, and resistance against denaturation in strong detergents, high-salt concentrations, and ionic liquids. This hyperthermophilic cellulase can enable the simultaneous pretreatment and (high-temperature) saccharification of lignocellulosic biomass. These two processes which are normally carried out in separate reaction vessels, can now be combined in one reaction tank. Details of the study are published in the journal, Nature Communications (URL above).
(full access to article may require payment or subscription) An international team of researchers from Austria (Alpen-Adria Universitat Klagenfurt e Wien e Graz), Germany (Potsdam Institute for Climate Impact Research), and United Kingdom (University of Leeds) attempted to use a biomass balance model to present "integrated food, livestock, agriculture, and bioenergy scenarios for the year 2050, based on a consistent representation of UN-FAO (United Nations Food and Agriculture Organization) projections of future agricultural development". From the analysis (which follows a "food first" approach), they attempted to estimate the global bioenergy potentials in the year 2050. The analysis covers 11 regions, 10 crop aggregates, 2 livestock aggregates, and 10 food aggregates, incorporating data on land use, global net primary production (NPP), and socioeconomic factors. Some highlights of the results include: (1) Global bioenergy potentials in 2050 excluding forestry are about 100 EJ/year (1 EJ is on Exajoule, a unit of energy equivalent to 1018 joules); this estimate could increase by 60% if "poorer" diets are chosen; (2) Food and livestock feed requirements strongly influence bioenergy potentials; (3) Food crop yields affect the area available for energy crops; (4) Climate-change impacts on bioenergy potentials may be substantial but are highly uncertain. The full paper is published in the journal, Biomass and Bioenergy (URL above). The full paper is published in the journal, Biomass and Bioenergy (URL above). Related information on the LPJmL model: http://www.pik-potsdam.de/research/climate-impacts-and-vulnerabilities/models/lpjml http://www.pik-potsdam.de/research/research-domains/climate-impacts-and-vulnerabilities/models/lpjml/lpjml_sab_09.pdf.
http://www.greencarcongress.com/2011/06/vtt-20110606.html In order to reduce dependence on fossil fuels and mitigate climate change, commercially available fuels today are being blended with biofuels. Ethanol-gasoline blends are one of the common biofuel-blended fuels that are available worldwide. Currently, there are two blends of bioethanol-blended petrol: the 98E5 (i.e. contains 5% anhydrous ethanol by mass) and the 95E10 (i.e. contains 10% anhydrous ethanol by mass) gasoline. The 95E10 blend has been frequently claimed to have higher car fuel consumption than the 98E5 blend, and this has led drivers to use this blend instead of the more environmental friendly 95E10 blend. Researchers from the VTT Technical Research Centre of Finland recently conducted a formal study comparing both blends in vehicle performance studies. They tested both blends in six-petrol driven cars, all compatible with the 95E10 fuel, under laboratory conditions. The volume of gasoline consumed based from the weight of fuel consumed was calculated. Results showed that the cars tested used an average of 10.30 liters of 95E10 per 100 km, as opposed to 10.23 liters of 98E5 per 100 km. The difference was 0.07 liters per 100 km in favor of 98E5 on average. This finding suggests that using 95E10 petrol, which has a higher ethanol content, increases consumption by 0.7%. Normalizing measurement results of each individual test run with observed slight scatter in actual total work done over the driving cycle yields to an adjacent overall difference of 1.0%. The empirical results were highly consistent to their theoretical value of 1.1% computed from an estimate of calorific values based on approximate fuel composition. Energy Crops and Feedstocks for Biofuels Production
http://dx.doi.org/10.1016/j.biortech.2010.06.139 An international team of researchers from Canada (Institut National de la Recherche Scientifique-Eau Terre Environnement), and India (the Government College and the National Institute for Interdisciplinary Science and Technology) recently reviewed the capability of macro- and microalgae as feedstocks for bioethanol production. Owing to the presence of large amounts of carbohydrates embedded in the physiology in algal cells, the utilization of algal biomass as feedstock for bioethanol production is considered promising. The use of oleagenous (oil-bearing) algae, in particular, is an attractive material because its oil can initially be extracted for biodiesel production, and then its high-carbohydrate residue can be processed for ethanol fermentation. Compared to terrestrial plant biomass (which is also a popular biofuel-ethanol feedstock), algae have higher growth rates. The authors made the review in anticipation of the greater use of macro- and microalgae for bioethanol production in the near future. In their study, they first presented the current scenario of bioethanol production in the world and the problems the industry is facing. Then they discussed the potential of macro- and microalgae as a bioethanol feedstock, from the cultivation stage to the processing stage wherein bioethanol is produced. Finally, they reviewed the roadblocks in using algae as bioethanol feedstock and they attempted to pinpoint keys in overcoming these roadblocks. According to the researchers, the utilization of algal biomass for bioethanol production is undoubtedly a sustainable and eco-friendly approach for renewable biofuel production. The full paper is published in the journal, Bioresource Technology (URL above). Biofuels Processing
http://dx.doi.org/10.1016/j.procbio.2010.08.027 Researchers from the Bio Engineering Laboratory, Department of Chemical Engineering, Monash University (Australia) investigated the conditions for the acid pretreatment of microalgal biomass (Chlorococcum humicola) for biofuel-ethanol production. Pretreatment is a process of breaking down the complex carbohydrates in the biomass into (ethanol-fermentable) sugars. Acid treatment (in combination with heat) is one of the commonly-used pretreatment methods. The researchers attempted to study the effects of different levels of acid concentration, temperature and pretreatment time on the amount of ethanol produced (after fermenting the sugars released from biomass pretreatment). Then they used a statistical approach (Response Surface Methodology, via Central Composite Design) to obtain the optimum pretreatment conditions. They found that at 140°C with 15 g/L of microalgae loading using 1% (v/v) of sulphuric acid for 30 minutes of pretreatment, the highest bioethanol of 7.20 g/L was obtained. On the other hand, the highest ethanol yield with a value 52wt% (g ethanol/g microalgae) was obtained at 160°C with 10 g/L of microalgae loading using 3% (v/v) of sulphuric acid for 15 minutes of pretreatment. Among the parameters, they found that temperature was the most critical factor during acid pre-treatment of microalgae for bioethanol production. The full paper is published in the journal, Process Biochemistry (URL above). Biofuels Policy and Economics
http://dx.doi.org/10.1016/j.reseneeco.2010.07.004 A "lively debate" and controversy has reportedly resulted when the increase in food prices in 2007 to 2008 were attributed to the biofuels development (which was stimulated by rising fossil fuel prices). "The simultaneous increase in price volatility and agricultural commodity markets" raises the question about the possible link between fossil energy and agricultural prices. Researchers from European Commission (DG Joint Research Centre) and Belgium (Catholic University of Leuven (LICOS) and the Economics and Econometrics Research Institute (EERI)) investigated the interdependencies of energy, bioenergy and agricultural commodity markets, using both theoretical and empirical approaches. In the theoretical approach, they extended existing models which developed a "vertical market integration model of ethanol, by-product, and corn markets." These extensions included (among others) the expansion of agricultural commodities from one to two, and the expansion of applicability to world markets (not only in the US). The empirical approach, which was based on cointegration analysis (related information below), "examined the existence of a long-run relationship between crude oil and agricultural commodity prices", by applying an error correction estimation procedure. Some highlights of their results are: (1) empirical findings support the theoretical hypothesis that the prices for crude oil and agricultural commodities are interdependent, (2) an increase in oil price by 1$/barrel increases the agricultural commodity prices between $0.10/tonne and $1.80/tonne, (3) the indirect input channel of price transmission is found to be small and statistically insignificant, which is contrary to theoretical predictions. The full paper is published in the journal, Resource and Energy Economics (URL above). Related information on co-integration analysis: http://www.econ.ku.dk/okokj/papers/dfhkjfnl.pdf
(full access to article may require payment or subscription) Researchers from the Department of Mechanical Engineering, Faculty of Engineering and Design, University of Bath, United Kingdom (UK) recently investigated the drivers and possible barriers for the development of bioenergy in the country. The study was made in anticipation of the shift in energy reliance from fossil-based energy to bioenergy, and this could be useful information for policy formulation/decision. The identification of bioenergy development drivers and barriers were based on a comprehensive literature and case study review. The researchers assessed their findings through an online questionnaire, completed by stakeholders from across the UK bioenergy industry (which includes farmers/suppliers, developers/owners of bioenergy projects, primary end-users, and government/policy stakeholders). From their findings, they found that the most critical barriers and drivers all relate to the economic factors of bioenergy projects. Farmers/suppliers and developers look into production costs and benefits, while primary end-users of bioenergy look into the cost of purchasing energy resources. The reduction in carbon emissions, as well as the reduction in fossil fuel dependency, were common drivers for all the stakeholders. The researchers suggest that in order for bioenergy projects to be successful, they must be both economically attractive and environmentally sustainable for it to satisfy the needs of the stakeholders. The full paper is published in the journal, Renewable and Sustainable Energy Reviews (URL above). |
||||||
