Technoeconomic Analysis of the Dilute Sulfuric Acid and Enzymatic Hydrolysis Process for the Conversion of Corn Stover to Ethanol

Technoeconomic analysis has been used to guide the research and development of lignocellulosic biofuels production processes for over two decades. Such analysis has served to identify the key technical barriers for these conversion processes so that research can be targeted most effectively on the pertinent challenges. The tools and methodology used to develop conceptual conversion processes and analyze their economics are presented here. In addition, the current process design and economic results are described for dilute acid pretreatment followed by enzymatic hydrolysis and fermentation. Modeled ethanol costs of $1.33/gallon (in consistent year 2007 dollars) are being targeted for this commercial scale corn stover conversion process in 2012. State of technology models, which take actual research results and project them to commercial scale, estimate an ethanol cost of $2.43/ gallon at present. In order to further reduce costs, process improvements must be made in several areas, including pretreatment, enzymatic hydrolysis, and fermentation. As the biomass industry develops, new fuels and new feedstocks are being researched. Technoeconomic analysis will play a key role in process development and targeting of technical and economic barriers for these new fuels and feedstocks.