Advanced direct coal liquefaction. Quarterly technical progress report No. 1, September-November 1983

Abstract

Wyoming subbituminous coal was liquefied using three different two-stage process configurations in bench-scale tests. These process configurations differed in the type of fractionated deashing resid being recycled to the individual stages. The objective of these runs was to determine whether, by recycle of specific resid streams to the thermal stage, the second stage catalyst life could be improved without detrimentally affecting distillate yield or hydrogen consumption. The results indicate that the two-stage process configuration consisting of hydrotreating the Light Deashed Resid and direct recycle of heavy Deashed Resid to the thermal stage produced the best results. This process configuration resulted in a distillate yield of 54 wt % (MAF coal basis) and overall coal conversion in the 93 to 95% range, as measured by pyridine-soluble analytical test while operating in a total distillate mode. These results are very encouraging from the lower rank Wyoming subbituminous coal. Among the three two-stage process configurations tested, the particular process configuration of hydrotreating Light Deashed Resid resulted in the least amount of catalyst deactivation. As a part of this research effort, a test procedure for quick evaluation of various resids and catalysts in terms of coke precursors was also developed. This procedure utilizing as-producedmore » oxide-form extrudates of catalyst is able to simulate closely in a batch reactor test the performance of a presulfided and extrudate form of catalyst in a continuous reactor. The CSD unit, being able to not only deash but also fractionate the resid, greatly increased the flexibility of options for coal liquefaction. New process concepts evolved incorporating reside fractionation and selective resid recycle in coal liquefaction. 17 figures, 28 tables.« less