In conjunction with work during 2008-2009 for the National Research Council in helping the NRC prepare its America’s Energy Future study, the Williams Group used Aspen Plus chemical process modeling software to model in detail more than thirty separate gasification-based plants that convert bituminous coal and/or switchgrass into electricity and/or synthetic liquid (primarily Fischer-Tropsch liquids (FTL), but also methanol to gasoline (MTG) as fuels for transportation, with and without CCS. The Aspen models provide key performance metrics as well as detailed component and stream information needed for component-level capital cost estimation.
The detailed results from the Aspen models are integrated into a Microsoft Excel framework used for calculating lifecycle greenhouse gas emissions, estimating component-level capital costs using a single algorithm for all plants, and for self-consistent comparative economic analyses of: 1) plant capital costs, 2) levelized costs for power and liquid fuels, 3) break-even crude oil prices, and 4) internal rates of return, as a function of key parameters such as: a) feedstock costs, b) carbon emissions price, and c) crude oil price. This dual Aspen/Excel methodology has proved to be a powerful tool for carrying out even-handed evaluations and comparisons of many disparate technologies. The Excel workbook is now available via download from the CMI web site. In addition, the group is working with the University’s Office of Information Technology (OIT) to convert the workbook into a flexible web application to increase its ease-of-use and to reach more potential users.