97/00999 Use of dispersed catalysts for direct coal liquefaction

Abstract

With dwindling supplies of petroleum products, efforts to utilize alternative energy feedstocks such as coal, is essential. Several areas in coal conversion technology have been identified that, if improved, could make coal liquefaction more cost competitive with petroleum. The objectives of this project are to address possible improvements in the economics by utilizing low-rank coals, new precursors to dispersed catalysts, and processing variations such as using syngas atmospheres. The purpose of the dispersed catalysts is to better control retrogressive reactions and avoid char formation, while the purpose of the carbon monoxide atmosphere is to improve the economics by simplifying or totally eliminating a separate water-gas-shift step, and perhaps help remove oxygen in the product slate. These possible improvements are being examined and evaluated for potential use in a 2-stage liquefaction process with the goal of converting coal to distillable liquids at a cost competitive to petroleum of $25/bbl. To evaluate our catalysts and process conditions, we used three types of laboratory-scale operations. In the first operation, we compared the reaction chemistry of various ranks of coals and catalysts in synthetic solvents such as hexadecane. This method allowed us to better compare our catalysts without the complications of solvent initiated chemistry.more » Once the catalysts were tested in this manner, they were examined for the conversions of a Black Thunder subbituminous coal using a recycle vehicle derived from the same coal as the solvent. Finally, we upgraded selected first-stage conversion products using a conventional hydrotreating catalyst to compare with recent results in two-stage coal liquefaction development. The results were evaluated for economic feasibility through a subcontract with Bechtel Corp.« less