부산대학교 도서관

Critical examination of available analytical data on fresh and used catalysts has disclosed that three common causes for catalyst deactivation, namely, sintering, metal deposition, and carbon deposition, contributed to the deactivation of the Co-Mo catalyst used in the H-Coal Process. Their relative detrimental effects on the catalyst vary with the rank of coal being processed and the process conditions. The Co-Mo catalyst is supported on gamma alumina. Operations with subbituminous coal such as Wyodak coal caused much more pronounced catalyst sintering than those using bituminous coal such as Illinois No. 6 coal. The high oxygen and high moisture content of Wyodak coal (in the event of incomplete drying) gives rise to a relatively high H/sub 2/O/H/sub 2/ ratio in the process gas. The pronounced effect of steam on sintering of catalyst at temperatures below 1000/sup 0/F is well known. Major metal contaminants found on the used catalyst are titanium, iron, calcium, and sodium. The magnitude of titanium deposition on catalyst from bituminous coal feed increased with catalyst age. Titanium deposition was concentrated to a depth of approximately 10 percent of the radius of spent /sup 1///sub 16/'' extrudate, whereas iron was found in clusters on the extrudate surface. The used catalyst contained 10 to 35 percent carbon. The extent of carbon deposition is affected more by process conditions than by either coal feed or by catalyst age. Low pressure operations conducted at 1000 psig or lower yielded high carbon deposition of over 22 percent.