Upgrading products from coal liquefaction by hydrotreating over zeolitic catalysts

Abstract

This article reports on the development of a group of catalysts based on NaY zeolite with the aim of upgrading coal distillates by hydrogenation using the IGI (Institute of Mineral Fuels) method. Intermediate calcinations were performed between the ion exchange stages in order to prepare suitable forms of the catalyst. Experiments were performed in a laboratory single-pass flow unit under the conditions used in petroleum refining to hydrotreat similar feedstocks. The rates of hydrodesulfurization and denitrogenation, and the selectivity of nitrogen removal, expressed as the ratio of degrees of denitrogenation and desulfurization, were calculated in order to evaluate the operation of the catalysts. The most difficult stage in hydrotreating is the removal of nitrogen bases. The feasibility of hydrotreating a 50-300/sup 0/C wide cut from products obtained by the liquefaction of lignite from the Kansko-Achinsk Basin, in the presence of zeolitic catalysts, is demonstrated. With regard to the selection of the cation-exchanged form of the zeolites and the promoters (palladium, molybdenum, cobalt, nickel), it is established that if thorough removal of phenols, nitrogen, and unsaturated hydrocarbons is necessary, the NiMoMeY catalyst should be selected and the NiMoHY catalyst is preferable in the process of hydrodesulfurization and decomposition of nitrogen bases.