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News and Trends
http://biopact.com/2008/03/scientists-unveil-genetics-of-plant.html Researchers from the United States Department of Energy Joint Genome Initiative (JGI) and their international collaborators are studying the inner workings of symbiotic plant-fungus relationships for potential applications in biofuel crop cultivation and phytoremediation. A possible scenario would be to harness the symbiosis to remediate/rehabilitate polluted soils using biofuel crops. The symbiotic relationship usually involves a group of fungi called Mycorrhizae, which thrive in the roots of the plant host and aids in the growth/survival of the plant. The fungus, in exchange, gets “protective root refuge” against other soil microbes. The symbiotic relationship is especially useful when the plant is grown in marginally productive or polluted soils. The JGI focus of study is the symbiotic relationship between fungi, called Laccaria bicolor, and woody trees of the genus Populus (examples, poplar and aspen). According to the JGI project web site, “characterizations of the interactions between Populus and its symbiotic associate, Laccaria bicolor , would allow in-depth exploration of the coordinated community response to these abiotic and biotic stresses, thus adding a needed dimension to climate change research and providing another step in the quest for mechanistic modeling of ecosystem responses”..
http://news.uns.purdue.edu/x/2008a/080306SzymanskiBiofuel.html “Third generation” biofuel feedstocks have been defined as crops whose properties have been modified (often by molecular biology techniques) to make them more amenable to specific bioconversion processes. Examples of recently reported third generation biofuel feedstocks are: “low-lignin transgenic trees”, or genetically modified maize with embedded cellulase enzymes in the leaves and stalk. Low lignin trees were developed to reduce costs of pretreating lignocellulosic biomass for cellulose-ethanol production. Cellulase-embedded stalks in maize also would reduce enzyme costs in the saccharification (cellulose to sugar conversion) step for cellulose-ethanol production. Recently, studies on signal proteins associated with plant cell wall development have been reported to potentially provide new tools for production of new third generation biofuel feedstocks. A team of scientists from Purdue University (United States) have discovered that a protein called “SPIKE1”, directs the protein signaling pathway associated with plant growth and cell wall development. By understanding the mechanisms that drive “SPIKE1”, the scientists hope to be able to develop tools to “design plants that are bigger and with more cell wall that can be processed into biofuel”. The results of their research are published in the Proceedings of the National Academy of Sciences (PNAS) (URL above)..
http://www.pnas.org/cgi/reprint/0708300105v1 The increase in corn cultivation in the United States is partly due to the increase in the demand for corn-based biofuels (i.e., corn ethanol). One of the effects of increased corn cultivation is the increased level of fertilizer use. Fertilizer application in corn fields in the Midwestern United States is said to be a “primary source of nitrogen that is exported to the Gulf of Mexico by the Mississippi and Atchafalaya Rivers”. The high levels of nitrogen, in the form of nitrates are causing the development of extensive (> 20,000 km2) hypoxic zones (areas of low oxygen concentration leading to stress/death in aquatic organisms) in the Gulf of Mexico. In an effort to reduce the annual spread of hypoxic zones to less than 5,000 km2, the Mississippi Basin/Gulf of Mexico Task Force has set a target of reducing nitrogen export by the Mississippi and Atchafalaya Rivers by 30%. However, a recent study by Simon Donner and Christopher Kucharik showed that “the increase in corn cultivation to meet the goal of 15-35 billion gallons of renewable fuels by 2002”, would “increase the flux of dissolved inorganic nitrogen (DIN) export by the Mississippi and Atchafalaya Rivers by 10–34%”. Through the use of simulation models, they showed that meeting the 15-billion-gallon-biofuel target would make “the already difficult challenges of reducing nitrogen export to the Gulf of Mexico practically impossible without large shifts in food production and agricultural management”..
http://www.csiro.au/news/AgreementWithChina.html The Commonwealth Scientific and Industrial Research Organization (CSIRO) of Australia and the Thermal Power Research Institute (TPRI) of China recently signed an agreement for a joint collaborative research in Post Carbon Capture Technology (PCC) in coal-fired power plants. Under the agreement, a pilot scale PCC facility will be installed at the Huaneng Beijing Co-Generation Power Plant as part of CSIRO’s research program. The pilot plant is reportedly designed to capture 3,000 tonnes of carbon dioxide per year from the power station. The performance of the PCC pilot plant will be evaluated under Chinese conditions. Briefly, Post Carbon Capture Technology “chemically traps” the carbon dioxide found in the “flue gas” (hot gases from the burning of coal) by a liquid solution. The liquid solution is then heated to release the trapped CO2, and reused. The liberated CO2 is subsequently compressed, liquefied and ultimately “stored” by “geo-sequestration techniques”, such as burial in deep geological formations, or burial in deep saline aquifers. PCC can equally be used in biomass-fired power generation plants, and could be an effective tool to mitigate climate change.. Energy Crops and Feedstocks for Biofuels Production
http://www.eurekalert.org/pub_releases/2008-03/babs-sua022908.php Fourth generation biofuel feedstocks, as described by the Biopact website (URL above), are crops that have been modified or processed to improve not only the biofuel conversion process, but also to impart a capability for “Carbon Capture and Storage” (CCS). These biofuel feedstocks are often considered “carbon negative”, meaning that the carbon dioxide absorbed during cultivation is higher than the carbon dioxide given off during its processing and use as biofuels. Imparting the capability for carbon dioxide capture can focus on modifying the plant (by molecular biology techniques) or by attaching additional processing steps during the production phase, to physically or chemically capture the carbon dioxide. When the latter is done, the captured CO2 goes to ultimate disposal, through deep burial in geological formations (“geosequestration”) or by other means. A recent study by researchers from the University of Essex (United Kingdom) provided new knowledge in the regulation of carbon dioxide fixation (the “carbon capture”) in plants. Details of the research are published in the Proceedings of the National Academy of Sciences (PNAS) (URL above). The results can open new strategies to increase the amount of carbon dioxide absorbed by the plants and hence, higher food or biofuel production yields. . Biofuels Processing
http://www.technologyreview.com/Energy/20151/ In the conventional bioprocess of ethanol production from lignocellulosic biomass (such as wood), the lignocellulosic components are first broken down into simple sugars, which are then converted to ethanol by yeast fermentation. The fermentation of the simple sugars by yeast can be considered “inefficient”, because part of the carbon in the sugars, are converted into carbon dioxide, instead of ethanol. An American start up company, Zeachem, has developed an ethanol production process from wood, which improves the carbon conversion efficiency to ethanol. The process, based on the use of termite-gut bacteria, called, Moorella thermoacetica, can reportedly produce “50% more ethanol from a given amount of biomass than conventional processes can”. In the process, the bacteria first convert the sugars from pre-processed wood into acetic acid, without the production of carbon dioxide. Then, through a series of chemical steps, the acetic acid is converted to ethanol. Through this process, no carbon is wasted because no carbon dioxide is produced. A visual overview of the process technology can be seen at the Zeachem website (URL indicated above).. Biofuels Policy and Economics
http://www.springerlink.com/content/f85977006m871205/?p=5abf4ef459644dfa9968169864fcd09d&pi=3 A scientific team from the Agricultural Research Service (ARS) of the United States Department of Agriculture (US-DA) and the University of Nebraska-Lincoln, recently published a study which determined the farm production cost of switch grass for use as raw material for cellulose ethanol production. Switch grass is a perennial grass that has been widely reported as a potential feedstock for cellulose ethanol production, on the basis of the following characteristics: (1) low agricultural inputs during cultivation, (2) good energy yield of the biofuel produced (after feedstock processing) and (3) lower greenhouse gas emissions of the biofuel produced (relative to gasoline). In a previous study, the same scientific team also obtained a better estimate of the actual energy yield of switch grass, using data from large scale switch grass plantations (related information below). The new study, published in the Bioenergy Research journal (URL above), also used data from commercial scale switch grass plantations of ten contract farmers, to assess farm production costs. The study region covered areas from North Dakota to southern Nebraska. The results showed that the average overall production cost across 5 production years was about $68.56 per Mg (1 Mg = 1 Mega gram = 1 metric ton). The researchers concluded that “substantial quantities of [switch grass] could have been produced in [the] region at about $50 per Mg." This would translate to about 13 cents per liter of ethanol. Related information: http://www.isaaa.org/kc/cropbiotechupdate/biofuels/default.asp?Date=1/11/2008#1935 |
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