A study conducted in the United States highlights that replacing gasoline or corn ethanol with cellulosic ethanol could be better for health and the environment than previously thought.
The research will be published this week on the website and soon in the print edition of the Proceedings of the National Academy of Sciences.
Cellulosic ethanol
Research suggests that cellulosic ethanol has fewer negative effects on human health because it emits lower amounts of fine particulate matter—a particularly harmful component of air pollution.
A previous study has shown that cellulosic ethanol and other next-generation biofuels also emit lower levels of greenhouse gases.
Beyond climate change
“Our work highlights the need to broaden the discussion about biofuels beyond climate change to include a broader range of impacts, such as their effects on air quality,” said lead author Jason Hill, a professor at the University of Minnesota’s Environment Institute.
The study evaluates the economic costs of cellulosic ethanol, corn ethanol, and gasoline to the environment and human health. The scientists conclude that, depending on the materials and technologies used in production, the environmental and health costs of cellulosic ethanol are less than half those of gasoline.
Moreover, the costs of using corn ethanol vary: they are at least equal to the costs of gasoline, and can be up to twice as high.
Economic impact of biofuel
To measure the economic impact of biofuels on the environment, scientists have developed a monetary estimate of the costs of mitigating the greenhouse gas emissions associated with burning biofuels and their entire production cycle.
The parameters used in this quantification were based on independent estimates of carbon mitigation costs, carbon market prices, and the social cost of carbon.
To measure the economic impact on health, average health system expenditures in North America were used along with the health effects of particulate matter exposure.
The total health and environmental cost of gasoline is $0.71 per gallon. The cost of the equivalent amount of corn ethanol ranges from $0.72 to $1.45, depending on the technology used in production. The same amount of cellulosic ethanol generates costs ranging from $0.19 to $0.32, depending on the technology and type of cellulosic material used.
Consumer Costs
These costs are not paid by producers or sellers of gasoline and ethanol. Consumers pay them, said co-author Stephen Polaski, a professor in the University of Minnesota’s Department of Applied Economics.
The researchers observed pollutants emitted at all stages of the life cycle of the three fuels, including production and consumption. They evaluated three corn ethanol production methods and four cellulosic ethanol production methods.
Beyond car pollution
“To understand the health and environmental consequences of biofuel use, we need to look beyond the pollution from cars and look at the production of these biofuels in detail. It has become clear that the emissions released during biofuel production are really important,” Hill said.
The study also suggests that other potential benefits of cellulosic biofuels — such as reducing the amount of fertilizers and pesticides dumped into rivers and lakes — could also mean additional economic benefits from moving to a new generation of biofuels.
