The Energy Research Initiative Presents the Alternative Liquid Fuels Simulation Model (AltSim)
Dr. Thomas E. Drennen, Scandia National Laboratories and Associate Professor of Economics at Hobart and William Smith Colleges
Monday, February 9, 2009
The Alternative Liquid Fuels Simulation Model (AltSim) is a high-level dynamic simulation model which calculates and compares the production costs, carbon dioxide emissions, and energy balances of several alternative liquid transportation fuels. These fuels include: corn ethanol, cellulosic ethanol, biodiesel, and diesels derived from natural gas (gas to liquid, or GTL), coal (coal to liquid, or CTL), and coal with biomass (CBTL). AltSim allows for comprehensive sensitivity analyses on capital costs, operation and maintenance costs, renewable and fossil fuel feedstock costs, feedstock conversion efficiency, financial assumptions, tax credits, CO2 taxes, and plant capacity factor.
This talk summarizes the structure and methodologies of AltSim, results, and provides a detailed sensitivity analysis. For the base cases, CBTL, CTL, and cellulosic ethanol are the least cost fuel options, at $1.27, $1.31, and $1.73 per gallon, respectively. Base case assumptions do not include tax or other credits. This compares to a $3.21/gallon production cost for gasoline at August 2008 crude oil prices ($117.50/barrel). On an energy content basis, the CBTL and CTL options remain the low cost alternatives ($10.30 and $10.62 per MMBTU), compared to $28.05/MMBtu for reformulated gasoline and $41.05/MMBtu for ethanol from corn. In the absence of carbon capture and sequestration for GTL, CTL, and CBTL, carbon emissions could actually increase by a large-scale move away from gasoline. A typical gasoline powered vehicle releases 5.7 tons CO2 per year, compared to 5.0, 6.9, 9.6 tons for vehicles fueled with cellulosic ethanol, corn ethanol, and CTL, respectively. With carbon capture and sequestration, the CBTL and CTL options would have emissions of 4.99 and 5.04 tons.
Thomas E. Drennen, Scandia National Laboratories and associate professor of economics at Hobart and William Smith Colleges, holds a Ph.D. in resource economics from Cornell University, a master's degree in public affairs from the University of Minnesota, and a bachelor of science degree in nuclear engineering from Massachusetts Institute of Technology. He received top awards and merits while studying at each institution, most notably having his Ph.D. dissertation nominated by Cornell University for the outstanding Doctoral Dissertation Award of the American Agricultural Economics Association.