| The current energy crisis has drawn much attention to cellulosic ethanol, but the chemical engineering system that produces this alternative fuel, called the biorefinery, has not yet been modeled with one of its primary feedstock suppliers, the agricultural system. Combining cropping and animal systems with the biorefinery in a single integrated model will allow environmental and economic analysis of biomass, bioenergy, co-product, and fertilizer production.;This study focuses on the integration of the NREL biorefinery model with the Integrated Farm System Model (IFSM), which is shown here to be the best choice for work with this biorefinery model. With these selected models, the biorefinery system is simulated within realistic agricultural landscapes, which include animal and crop production, across various US regions using the new research tool Biorefinery and Farm Integration Tool (BFIT). This combined modeling approach allows analysis of regional variability, economic profitability, and development pathways with little environmental impact. Preliminary results from this model development study indicate that the Midwest, already a center for grain ethanol production, is ideal for the cellulosic ethanol industry. This study also underscores the need for continued research on the use of biorefinery co-products, specifically pretreated grasses, as animal feed.;Although validation of the research tool developed in this work can only occur when commercial scale biorefineries and biomass markets are operational, a sensitivity analysis and verification are presented at this time. The sensitivity analyses reveal three variables having notable effects on overall system outcomes: biorefinery size, biomass farm gate price, and switchgrass yields. These analyses stress the need for care with model input assumptions and continued research on these variables.;The verification tests performed at the conclusion of this study highlight this model's potential for "expert users" as a decision-making tool. The outcomes of these tests lay the ground work for future studies using this research tool, while also pointing to areas that would benefit from further expansion and validation. Specifically, future research should investigate the effects of combined changes in precipitation and temperature, biomass choice, and land use, as defined by the farm management distribution in the landscape. |
