Biofuels: More than just ethanol

Apr 05, 2007

As the United States looks to alternate fuel sources, ethanol has become one of the front runners. Farmers have begun planting corn in the hopes that its potential new use for corn will be a new income source. What many don't realize, is the potential for other crops, besides corn, to provide an alternate energy source to fossil fuels. Scientists studied the greenhouse gas emissions and bioenergy of corn, hybrid poplar, switchgrass, and other crops to determine the efficiency of various biocrops in terms of energy consumption and energy output.

The study, "Net greenhouse gas flux of bioenergy cropping systems using Daycent", was completed by Paul Adler (United State Department of Agriculture - USDA), Stephen Del Grosso (USDA and Colorado State University), and William Parton (Colorado State University). Results appear in the April issue of Ecological Applications.

"Biofuels have a great potential to reduce our dependence on gasoline and diesel fuel," says Parton. "We have performed a unique analysis of the net biofuel greenhouse emissions from major biofuel cropping systems by combining ecosystem computer model data with estimates of the amount of fossil fuels used to grow and produce crop biofuels."

Adler, Del Grosso and Parton used the Daycent biogeochemistry model, developed by Parton and Del Grosso to asses greenhouse gas fluxes and biomass yields for corn, soybean, alfalfa, hybrid poplar, reed canary grass and switchgrass.

The results of the study showed that when compared with gasoline and diesel, ethanol and biodisel from corn and soybean rotations reduced greenhouse gas emissions by almost 40 percent, reed canarygrass by 85 percent. Greenhouse gas emissions were reduced by about 115 percent for switchgrass and hybrid poplar. Both switchgrass and hybrid poplar offset the largest amounts of fossil fuels reduced emissions compared to other biofuel crops and offset two times as much fossil fuels if they are used for electricity generation via biomass gasification.

Study results showed that nitrogen (N2O) emission resulting from production of the biofuel crops is the largest greenhouse gas source, while displaced fossil is the largest greenhouse gas sink followed by soil carbon sequestration.

This research shows that farmers will have a variety of biofuel crop options available in the future and that these biofuel crop rotations will have different environmental impacts. Detailed studies of the environmental impact of biofuel crops similar to this study need to be done at the regional and national levels before biofuel national policy decisions are finalized.

Source: Ecological Society of America

Explore further: Mountain of electrical waste reaches new peak

Related Stories

Recommended for you

Mountain of electrical waste reaches new peak

8 hours ago

A record amount of electrical and electronic waste hit the rubbish tips in 2014, with the biggest per-capita tallies in countries that pride themselves on environmental consciousness, a report said Sunday.

China's struggle for water security

Apr 18, 2015

Way back in 1999, before he became China's prime minister, Wen Jiabao warned that water scarcity posed one of the greatest threats to the "survival of the nation".

Canada revises upward CO2 emission data since 1990

Apr 18, 2015

Canada revised its greenhouse gas emission data from 1990 to 2013 in a report Friday, showing it had higher carbon dioxide discharges each year, and a doubling of emissions from its oil sands.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.