Minnesota Project releases biofuels update

By Craig A. Johnson | October 06, 2009
The Minnesota Project recently released a study titled "Transportation Biofuels in the United States: An Update," which details the progress made in cellulosic ethanol and corn ethanol research, and discusses biofuels generally. The study focused on four main cellulosic feedstocks, including: corn stover, miscanthus, switchgrass and wood.

Dealing with many of the most divisive issues in the public debate over ethanol, the report specifically rebuts claims made regarding ethanol's energy efficiency and water usage, as well as land use theory and food versus fuel arguments.

Bringing to light facts about biofuels, the study notes a University of Nebraska-Lincoln study which found that for every unit of fossil energy input, 1.5 units to 1.8 units of energy are created in the form of ethanol. The study also pointed out that replacing natural gas with biomass combined heat and power facilities dramatically improves the energy ratio.

According to the report, the ubiquitous food versus fuel debate highlights the conflation of entangled facts that make two separate issues seem like corollaries. In 2007 and 2008, along with rising inflation, corn prices constantly increased, leading casual observers to conclude the price increase was caused by ethanol production. Citing the Congressional Budget Office, the study stated "the rise in price of corn resulting from expanded ethanol production contributed between 0.5 and 0.8 percentage points of the 5.1 percent increase in food prices over that time."

Along with food versus fuel, the indirect land use change theory is another thorny issue in the public's perception of ethanol. The Minnesota Project concluded, "For the sake of effectively addressing global warming, we must have accurate analysis of the total carbon impact of biofuels. Just as ignoring some components' contributions to carbon emissions would limit the effectiveness of biofuels in reducing greenhouse gas emissions, so too would overestimating the carbon impact of biofuels production by inhibiting the growth of replacement fuels for petroleum and transportation fuels."

A key issue for many in the ethanol industry is the use of corn stover to produce ethanol. The report viewed the practice negatively, as corn stover provides needed nutrients for healthy soil. According to the report, "harvesting of corn stover holds the greatest potential for negatively impacting soil erosion and water quality…. Stover also helps prevent soil erosion by slowing surface water runoff and increasing water retention. Removing stover from farmland has the potential to harm soil productivity and increase erosion which can then reduce water quality through increased sedimentation and nutrient runoff."

In addition to soil erosion, water use has become a primary concern for ethanol production in areas which experience frequent droughts, or where concerns over consumption or pollution may hinder construction and operation. The report noted that in 2005, the ethanol production process required an average of 4.2 gallons of water to produce 1 gallon of ethanol, with most of the water being lost during cooling. "Corn ethanol facilities have made water efficiency advancements in recent years to cut water usage by 20 percent or more. New technologies that make use of gray water for cooling purposes or recycle water for reuse could dramatically cut the water demand of corn ethanol facilities to below the average 2.25 gallons of water that petroleum refineries consume to produce 1 gallon of gasoline."

And with cellulosic ethanol on the horizon, the gains are even greater. "Cellulosic biofuels, in comparison, have lower estimated water demands. Many technologies extract water from biomass material as part of the process of extracting the cellulose…. Some technologies have even shown promise to produce a net excess of water."

The Minnesota Project is a nonprofit organization that promotes the sustainable production and equitable distribution of energy and food in communities across Minnesota.