Biofuels Supplement

News and Trends

Studies on Lignin Formation and Structure in Plant Cell Walls Could Provide Opportunities for Breaking the “Lignin Barrier” in Cellulose Ethanol Production Technology
http://www.ars.usda.gov/is/AR/archive/apr07/walls0407.htm
http://biopact.com/2007/04/scientists-break-down-lignin-to-enter.html

“Cellulose ethanol” production involves the conversion of plant cellulosic biomass into ethanol. The cellulose (chains of glucose molecules) in plant cell walls are broken down (by a process known as “saccharification”) into individual glucose units.  The individual glucose molecules are then converted into ethanol by microbial fermentation.  Lignin is a chemical substance that tightly wraps the cellulose fibers in the plant cell walls, and acts as a barrier for effective cellulose utilization. The destruction of the “lignin barrier” is one of the challenges in cellulose ethanol production technology. Physico-chemical methods like steam explosion or use of chemicals are commonly used.

Scientists from the U.S. Dairy Forage Research Center (DRFC) are taking an alternative approach to finding solutions for the “lignin barrier”.  By understanding lignin formation and structure in plant cell walls, they hope to “provide opportunities to modify lignin composition and content”, probably in “designer” crops specifically planted for biofuels. John Ralph, a chemist at DFRC, has been studying changes in altered lignin structures in transgenic plants, and these studies have provided basic knowledge on how lignin formation occurs in plant cell walls.  One of his interesting findings: lignin formation has “metabolic plasticity”; that is, plants have many possible combinations for assembling lignin in plant cell walls from a variety of building blocks.  Ralph sees lignin formation as an “evolved solution that allows plants considerable flexibility in dealing with various environmental stresses”.  Another researcher from Ralph’s laboratory, Fachuang Lu, has developed a tool for studying ultrafine chemical structure of the entire plant cell wall. Their work is featured in the April 2007 issue of Agricultural Research.

Related Information:  Plant cell wall basics:  http://genomicsgtl.energy.gov/biofuels/placemat2.shtml


Process Converts Any Lipid-based Raw Material to Aviation Biofuels
http://news.ncsu.edu/releases/2007/feb/031.html
http://www.diversified-energy.com/auxfiles/centia/CentiaExecutiveSummary.pdf
http://www.insidegreentech.com/node/739

Engineers from North Carolina State University (NCSU) and Diversified Energy Corporation (DEC) in the United States are testing a patent-pending process which can convert any lipid-based raw material (oils or fats derived from plant or animal sources) into high value aviation biofuel (for jet engines) or additives for cold-weather biofuels. New advantages of the process is that even low quality lipid products like cooking grease can be used, and that there are no more disposal problems associated with the waste by-product, glycerol. Aviation biofuels have more stringent requirements for energy density, combustion, and cold flow properties than traditional biofuels.  The process  (called “CentiaTM), involves a three-step thermo-catalytic reforming process.  In the first stage (called hydrolysis), the feedstock is subjected to high temperature and pressure to strip off the free fatty acids (FFA) from the glycerol backbone of the lipid.  The glycerol waste by-product is burned off for energy, while the FFA enters the second step.  In the second stage (the decarboxylation step),  the FFA’s and a solvent are heated under pressure with a catalyst to remove carbon dioxide, resulting in the formation of straight chain hydrocarbons (called “alkanes”) that are 15 or 17 carbon atoms (C15 or C17) long. The aviation biofuel is then produced in the third step (the reforming step), where  the straight chained C15 or C17  alkanes are reformed into branched “iso-alkanes” containing 10 to 14 carbon atoms.  So far, this is said to be the first process ever to produce a biofuel that is jet-compliant.  The team is currently furthering the maturity of the technology and is “seeking investors and strategic partners for full-scale bench testing, pilot plant development, feedstock supply, and fuels purchase agreements.”

Energy Crops and Feedstocks for Biofuels Production

Philippine National Oil Company (PNOC) Eyes Algae as Potential Biodiesel Source
http://www.pia.gov.ph/default.asp?m=12&r=&y=&mo=&fi=p070329.htm&no=11
http://business.inquirer.net/money/topstories/view_article.php?article_id=57627

The Alternative Fuels Group (AFC) of the Philippine National Oil Company (PNOC) is considering the introduction of biodiesel derived from algae next year. Peter Anthony Abaya, CEO of the PNOC-AFC says that the development and eventual commercialization of next generation of biofuels of part of  PNOC-AFC’s medium-term development plan.  Algae is said to be one of the promising “next generation biofuels”.  Planned talks are underway with a pioneering U.S. ecotechnological company engaged in algae-to-biodiesel technology. (The name of the company was not named).

Algae is efficient in sequestering carbon dioxide from the atmosphere, and its propagation is said to be simple and fast.  The costs of production of  algae-derived biodiesel are also said to be potentially lower.  Data from a test facility showed that algae could produce between 1,600 to 2,000 tons of oil per hecatare in one year.  In contrast, yields of Jatropha  and Palm oils are only 3 tons per hectare and 6 tons per hectare, respectively.  Calculations estimate a cost  $25 per ton of oil from algae, which is only about 5% the cost of obtaining oil from one hectare of palm.  The spent algae from oil processing could also be used as animal feed or soil fertilizer.
 
Abaya said that he would go back to the U.S. in a month or so, to possibly close a deal on the technology.

Biofuels Processing

Thermochemical Process Turns Plant Biomass into Bio Oil
http://www.ars.usda.gov/is/pr/2007/070406.htm

Scientists from the Easter Regional Research Center (ERRC), Agricultural Research Service (ARS) of the U.S. Dept of Agriculture have developed a bench scale fluidized bed reactor which can convert plant biomass like switchgrass and corn stover into liquid “bio oil”.  The biomass-to-oil conversion utilizes a process called “pyrolysis”.  In this process, extreme heat is applied to the raw material in an oxygen-free environment.  This results in the breakdown of plant organic matter and its subsequent conversion into “bio oil”.  The liquid oil recovery in the process is maximized by the incorporation of an electrostatic precipitator (ESP), which is a “filtering device that removes fine liquid droplets from the gas flow”.  The resulting “bio oil” product is said to have a higher energy density and superior transportability due to its low water content.  The product can be further refined into standard diesel oil.


Application of Enzymes in Milled Corn Improves Ethanol Production Efficiency
http://www.ars.usda.gov/is/pr/2007/070409.htm

In an effort to increase ethanol production efficiency of corn feedstocks, scientists at the Crop Conversion Science and Engineering Research Unit of the Eastern Regional Research Center (ERRC) in the United States are evaluating the effects of adding protease enzymes from bacterial and fungal sources.   They report that addition of protease enzymes improves nutrient availability for ethanol-fermenting yeasts, and it also facilitates the dewatering of solid residue after ethanol fermentation and extraction.  A field trial at a small wet milling facility in Penang, Malaysia showed that the addition of enzymes after soaking the corn, improved starch recovery, hence more raw material for ethanol.

Biofuels Policy and Economics

Biogeochemistry Model and Life Cycle Analysis Used to Evaluate Biofuel  Greenhouse Gas Releases from Different Cellulosic and Non-Cellulosic (Grain and Oilseed) Feedstocks
http://newsinfo.colostate.edu/index.asp?url=news_item_display&news_item_id=11182593
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=208139
http://biopact.com/2007/04/researchers-analyse-greenhouse-gas.html

Ethanol and biodiesel are the most common biofuels.  In the United States, the main biofuel crops are corn for ethanol and soybean for biodiesel.  Recently, cellulosic biomass, such as switchgrass, alfalfa, reed canary grass and hybrid poplar, have been proposed as “future dedicated energy crops”.  Some of these crops were analyzed by researchers from the Colorado State University, Natural Resource Ecology Laboratory and the U.S. Department of Agricujlture (USDA), Agricultural Research Service (ARS) for their capacity to reduce greenhouse gas (GHG) emissions. Using life cycle analysis and the DAYCENT Biogeochemistry model, they found that cellulosic biomass feedstocks (switchgrass and hybrid poplar) can reduce GHG emissions by about 115%.  Non-cellulosic biomass (corn ethanol and soybean biodiesel) could do the same by only 40%.  Reed canary grass can reduce GHG emissions by 85%.  Although GHG-emitting fossil-fuel-inputs are inevitable in biofuel production, bioenergy crops have the ability to offset this by absorbing CO2 greenhouse gases while they are grown in plantations.  Stephen Grosso, USDA scientist, mentions that the evaluation highlights the need to improve large scale biomass-to-energy conversions and to exploit more fully agricultural co-products.


Biotechnology Industry Organization Reports on “Achieving Sustainable Production of Agricultural Biomass for Biorefinery Feedstock”
http://www.bio.org/ind/biofuel/SustainableBiomassReport.pdf

The Biotechnology Industry Organization lists some policy recommendations in order to achieve the sustainable production of cellulosic biomass for biofuel production.  Some of the recommendations are: (1) development and distribution of simple-to-use soil carbon models to allow farmers to compute how much crop residue can be collected without degrading soil quality; (2) funding for demonstration projects to streamline collection, transport and storage of cellulosic crop residue feedstocks, (3) development of a system to monetize greenhouse gas credits generated by production of ethanol and other products from agricultural feedstocks, (4) funding for programs to help farmers identify and grow the most suitable crops for both food production and cellulosic biomass production.