Turning Waste Material into EthanolAugust 14, 2008AMES, Iowa -Say the word "biofuels" and most people think of grain ethanol and biodiesel. But there's another, older technology called gasification that's getting a new look from researchers at the U.S. Department of Energy's Ames Laboratory and Iowa State University. By combining gasification with high-tech nanoscale porous catalysts, they hope to create ethanol from a wide range of biomass, including distiller's grain left over from ethanol production, corn stover from the field, grass, wood pulp, animal waste, and garbage. Gasification is a process that turns carbon-based feedstocks under high temperature and pressure in an oxygen-controlled atmosphere into synthesis gas, or syngas. Syngas is made up primarily of carbon monoxide and hydrogen (more than 85 percent by volume) and smaller quantities of carbon dioxide and methane. It's basically the same technique that was used to extract the gas from coal that fueled gas light fixtures prior to the advent of the electric light bulb. The advantage of gasification compared to fermentation technologies is that it can be used in a variety of applications, including process heat, electric power generation, and synthesis of commodity chemicals and fuels. "There was some interest in converting syngas into ethanol during the first oil crisis back in the 70s," said Ames Lab chemist and Chemical and Biological Science Program Director Victor Lin. "The problem was that catalysis technology at that time didn't allow selectivity in the byproducts. They could produce ethanol, but you'd also get methane, aldehydes and a number of other undesirable products." A catalyst is a material that facilitates and speeds up a chemical reaction without chemically changing the catalyst itself. In studying the chemical reactions in syngas conversion, Lin found that the carbon monoxide molecules that yielded ethanol could be "activated" in the presence of a catalyst with a unique structural feature. Syngas Nanoscale Catalysts In this transmission electron micrograph of the mesoporous nanospheres, the nano-scale catalyst particles show up as the dark spots. Using particles this small (~ 3nm) increases the overall surface area of the catalyst by roughly 100 times. "If we can increase this 'activated' CO adsorption on the surface of the catalyst, it improves the opportunity for the formation of ethanol molecules," Lin said. "And if we can increase the amount of surface area for the catalyst, we can increase the amount of ethanol produced." Lin's group looked at using a metal alloy as the catalyst. To increase the surface area, they used nano-scale catalyst particles dispersed widely within the structure of mesoporous nanospheres, tiny sponge-like balls with thousands of channels running through them. The total surface area of these dispersed catalyst nanoparticles is roughly 100 times greater than the surface area you'd get with the same quantity of catalyst material in larger, macro-scale particles. It is also important to control the chemical makeup of the syngas. Researchers at ISU's Center for Sustainable Environmental Technologies , or CSET, have spent several years developing fluidized bed gasifiers to provide reliable operation and high-quality syngas for applications ranging from replacing natural gas in grain ethanol plants to providing hydrogen for fuel cells. "Gasification to ethanol has received increasing attention as an attractive approach to reaching the Federal Renewable Fuel Standard of 36 billion gallons of biofuel," said Robert Brown, CSET director. "The great thing about using syngas to produce ethanol is that it expands the kinds of materials that can be converted into fuels," Lin said. "You can use the waste product from the distilling process or any number of other sources of biomass, such as switchgrass or wood pulp. Basically any carbon-based material can be converted into syngas. And once we have syngas, we can turn that into ethanol." The research is funded by the DOE's Offices of Basic Energy Sciences and Energy Efficiency and Renewable Energy. Ames Laboratory is a U.S. Department of Energy Office of Science laboratory operated for the DOE by Iowa State University. The Lab conducts research into various areas of national concern, including the synthesis and study of new materials, energy resources, high-speed computer design, and environmental cleanup and restoration . Ames Laboratory |
|||||||||||||||||||||
| Related Ethanol Current Events and Ethanol News Articles UC Riverside Researchers Create First Synthetic Cellulosome in Yeast A team of researchers led by University of California, Riverside (UCR) Professor of Chemical Engineering Wilfred Chen has constructed for the first time a synthetic cellulosome in yeast, which is much more ethanol-tolerant than the bacteria in which these structures are normally found. Propolis has proved to be a product with ability to have beneficial effects for health Growing concerns about health has caused the scientific community to focus their interest on investigating functional foods which contribute to boosting the prevention and reduction of the risk of suffering from certain illnesses. Standards for a new genomic era A team of geneticists at Los Alamos National Laboratory, together with a consortium of international researchers, has recently proposed a set of standards designed to elucidate the quality of publicly available genetic sequencing information. 0.2 second test for explosive liquids Since a failed terrorist attack in 2006, plane passengers have not been able to carry bottles of liquid through security at airports, leaving some parched at the airport and others having expensive toiletries confiscated, but work by a group of physicists in Germany is paving the way to eliminate this necessary nuisance. Report examines hidden costs of energy production and use A new report from the National Research Council examines and, when possible, estimates "hidden" costs of energy production and use -- such as the damage air pollution imposes on human health -- that are not reflected in market prices of coal, oil, other energy sources, or the electricity and gasoline produced from them. Tech researchers using nanotechnology in biofuel process to save money, environment Dr. James Palmer, associate professor of chemical engineering at Louisiana Tech University, is collaborating with fellow professors Dr. Yuri Lvov, Dr. Dale Snow, and Dr. Hisham Hegab to capitalize on the environmental and financial benefits of "biofuels" by using nanotechnology to further improve the cellulosic ethanol processes. Strategy outlined for growing bioenergy while protecting wildlife A study described in the October issue of BioScience identifies diverse native prairie as holding promise for yielding bioenergy feedstocks while minimizing harm to wildlife. Study shows more corn for biofuels would hurt water More of the fertilizers and pesticides used to grow corn would find their way into nearby water sources if ethanol demands lead to planting more acres in corn, according to a Purdue University study. Binge drinkers let down guard against infection As if a bad hangover wasn't enough of a deterrent, new research has shown how binge drinking weakens the body's ability to fight off infection for at least 24 hours afterwards. US tax breaks subsidize foreign oil production The largest U.S subsidies to fossil fuels are attributed to tax breaks that aid foreign oil production, according to research to be released on Friday by the Environmental Law Institute (ELI) in partnership with the Woodrow Wilson International Center for Scholars. More Ethanol Current Events and Ethanol News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||