University of Minnesota
February 3, 2009
Ethanol made from cornstalks and other biomass holds promise for reducing health hazards as well as pollution.
Ethanol from cellulose may mean lower costs to health and the environment than gasoline or corn ethanol
By Becky Beyers
Saying "fill 'er up" with cellulosic ethanol instead of gasoline or corn-based ethanol may be even better for our health and the environment than previously recognized, a new University of Minnesota study shows.
Cellulosic ethanol—made from wood, grasses, or the non-edible part of plants—has fewer harmful effects on human health because it emits smaller amounts of fine particulate matter, an especially damaging component of air pollution, the researchers find.
Earlier work showed that cellulosic ethanol and other new biofuels also emit lower levels of greenhouse gases.
The study will be published in the journal Proceedings of the National Academy of Sciences later this month and will be posted online this week.
"Our work highlights the need to expand the biofuels debate beyond its current focus on climate change to include a wider range of effects, such as their impacts on air quality," says lead author Jason Hill, a resident fellow in the University of Minnesota's Institute on the Environment.
The study is the first to estimate the economic costs to human health and well-being from gasoline, corn-based ethanol, and cellulosic ethanol made from biomass.
Watch a video of Jason Hill discussing his research into cellulosic ethanol.
The researchers found that depending on the materials and technology used in production, cellulosic ethanol's environmental and health costs (19 to 32 cents per gallon) are less than half the costs of gasoline (71 cents per gallon), while corn-based ethanol's costs (72 to about $1.45 per gallon) range from roughly equal to about double that of gasoline.
"These costs are not paid for by those who produce, sell, and buy gasoline or ethanol. The public pays these [health and environmental] costs," says study co-author Stephen Polasky, a professor in the University's applied economics department.
The authors looked at pollutants emitted at all stages of the life cycles of the three types of fuel, including when they are produced and used. They considered three methods of producing corn-based ethanol and four methods of producing cellulosic ethanol.
"To understand the environmental and health consequences of biofuels, we must look well beyond the tailpipe to how and where biofuels are produced. Clearly, upstream emissions matter," Hill says.
The paper also points out that other potential advantages of cellulosic biofuels, such as reducing the amount of fertilizer and pesticide runoff into rivers and lakes, may also add to the economic benefit of transitioning to next-generation biofuels.
Regents Professor David Tilman of the University's ecology, evolution and behavior department also contributed to the paper, as did scientists from Stanford University and the Argonne National Laboratory of the U.S. Department of Energy. The Initiative for Renewable Energy and the Environment, a signature program of the University of Minnesota's Institute on the Environment, provided a portion of the research funding.