Ethanol always not as green as some believe
Ethanol not always as green as some believe
February 16, 2007
Ethanol is generally not as green as some people believe says Bruce Dale, Michigan State University professor of chemical engineering and materials science.
Speaking at the American Association for the Advancement of Science annual meeting in San Francisco, Dale says that while corn ethanol produces less greenhouse gases than gasoline, it can cause other detrimental environmental effects if not carefully managed.
“Biofuels can provide large environmental benefits when compared to gasoline or petroleum diesel,” said Dale. “But if we’re going to fully realize the environmental potential of biofuels, we need to plan carefully. For example, producing ethanol from corn grain can release large amounts of nitrous oxide, a greenhouse gas that is 300 times more potent than carbon dioxide, into the environment. It’s possible to minimize nitrous oxide emissions and significantly improve the greenhouse gas profile of ethanol, but we need to be aware of and deal squarely with this issue.”
Dale said that the use of cover crops — such as rye grass during the winter — can reduce greenhouse gas emissions significantly, while rasiging levels of organic nutrients in the soil. He also notes that harvesting corn stalks or the cover crop to make cellulosic ethanol can cut nitrous oxide emissions and reduce the use of gasoline usually used for corn production.
“We need to carefully consider and intelligently manage the entire ethanol production system for long- term sustainability — not just focus on pieces of the system,” Dale said. “Ethanol is and will be a critical part of reducing our national dependence on oil for liquid fuels. Production technology for both corn and cellulosic ethanol is advancing rapidly. So it’s essential that we understand how to improve all portions of the system for maximum environmental benefits.”
Corn waste potentially useful for more than ethanol. After the corn harvest, whether for cattle feed or corn on the cob, farmers usually leave the stalks and stems in the field, but now, a team of Penn State researchers think corn stover can be used not only to manufacture ethanol, but to generate electricity directly.
Soybean biodiesel has higher net energy benefit than corn ethanol – study. The first comprehensive analysis of the full life cycles of soybean biodiesel and corn grain ethanol shows that biodiesel has much less of an impact on the environment and a much higher net energy benefit than corn ethanol, but that neither can do much to meet U.S. energy demand.
Biomimicry of native prairie yields more.
Diverse mixtures of plants that mimic the native prairie ecosystem are a better source of biofuels than corn grain ethanol or soybean biodiesel according to a new paper published in the Dec. 8 issue of the journal Science.
High oil prices fuel bioenergy push. High oil prices and growing concerns over climate change are driving investment and innovation in the biofuels sector as countries and industry increasingly look towards renewable bioenergy to replace fossil fuels. Bill Gates, the world’s richest man, has recently invested $84 million in an American ethanol company, while global energy gluttons ranging from the United States to China are setting long-term targets for the switch to such fuels potentially offering a secure domestic source of renewable energy and fewer environmental headaches.
Biofuels can replace about 30 percent of fuel needs. With world oil demand growing, supplies dwindling and the potential for weather- and conflict-related supply interruptions, other types of fuels and technologies are needed to help pick up the slack. A group of experts in science, engineering and public policy from the Georgia Institute of Technology, the Imperial College London and the Oak Ridge National Laboratory recommend a comprehensive research and policy plan aimed at increasing the practicality of using biofuels and biomaterials as a supplement to petroleum. The review article, called “The Path Forward for Biofuels and Biomaterials,” appears in the Jan. 27 issue of Science.
Ethanol more energy-efficient than oil, finds study.
Using ethanol — alcohol produced from corn or other plants — instead of gasoline is more energy-efficient than oil say researchers at the University of California, Berkeley. In a study published in Friday’s issue of the journal Science, Berkeley scientists show that producing ethanol from corn uses much less petroleum than producing gasoline.
This article is based on a news release from Stanford University .