Reply #10: This Report Appears To Be An Outlier [View All]

[Strelnikov_]

Most studies indicate an EPR of 1.3 to 1.8 for corn ethanol. Most of the feed value of the grain remains after processing. Cellulosic ethanol, if if pans out, would be even better in that perennial crops grown on marginal agricultural land could be utilized.

The Energy Balance of Corn Ethanol: An Update / AER-813
United States Department of Agriculture - July 2002

http://www.usda.gov/oce/oepnu/aer-813.pdf

The above publication indicates that the EROEI (EPR) of corn ethanol is 1.34 to 1.85 dependant on how the value of coproducts (DDGS, germ, etc.) is accounted for. What I found interesting was Table 6 that indicates 2/3's of the energy consumed is in the conversion process. This indicates opportunities for utilizing co-generation or renewables (wind) for some of this process energy.

Thus, corn ethanol appears to have a future role, at a minimum, as an energy carrier. Considering current hydrogen generation has an EROEI of 0.20, corn ethanol at and EROEI of 1.3 looks pretty good.

Just east of Ames, IA an ethanol processing plant is being built. In the brief for the project they advertised how the new plant will use the same coal supply delivered to the Ames, IA municipal electric plant 4 mi. to the west, thus resulting in savings. With co-generation, this plant could have been located such that waste heat from the coal fired electric plant could have been utilized by the ethanol process. In addition, the Ames power plant burns local garbage, therefore waste material from the ethanol process could be burned (resource recovered, as they call it).

The following report indicates that 1 b Ton/yr of biomass would be required to replace 30% of current petroleum consumption.

Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply, April 2005:

http://www.eere.energy.gov/biomass/pdfs/final_billionton_vision_report2.pdf

The purpose of this report is to determine whether the land resources of the United States are capable of producing a sustainable supply of biomass sufficient to displace 30 percent or more of the country’s present petroleum consumption – the goal set by the Advisory Committee in their vision for biomass technologies. Accomplishing this goal would require approximately 1 billion dry tons of biomass feedstock per year.

The short answer to the question of whether that much biomass feedstock can be produced is yes. Looking at just forestland and agricultural land, the two largest potential biomass sources, this study found over 1.3 billion dry tons per year of biomass potential — enough to produce biofuels to meet more than one-third of the current demand for transportation fuels. The full resource potential could be available roughly around mid-21st century when large-scale bioenergy and biorefinery industries are likely to exist. This annual potential is based on a more than seven-fold increase in production from the amount of biomass currently consumed for bioenergy and biobased products. About 368 million dry tons of sustainably removable biomass could be produced on forestlands, and about 998 million dry tons could come from agricultural lands.

The problem is, there is no way biomass/renewables will replace the Quads of liquid fuel energy we currently consume. This does not have to mean the end of personal transport. But it does mean the end of the age of 6000 lb. 4 wheel living rooms flying down the highway at 75 mph. If cars today averaged 100 mpg, we would reduce petroleum consumption by 34%. Replace an additional 30% with biomass sources per the report, we start to make a real dent in our petroleum 'habit'. And all with todays technology.