Recent technological developments in Fischer-Tropsch catalysis

Abstract

Fischer-Tropsch Synthesis is a promising, long-term, option for environmentally sound production of chemicals and fuels from coal. This paper focuses on catalyst and process developments which have occurred in the past decade. It features three important areas of FT catalysis: chemical modifications (additives, promoters, supports, pretreatments, and preparation methods), interception of intermediates (dual functionalism and secondary reactions), and limitation of chain growth by shape selectivity. Fundamental principles of catalyst design are emphasized. Conventional FT catalyst/process technology suffers from the following limitations: (1) limited selectivity for premium products (e.g. olefins, gasoline, and diesel fuel), (2) catalyst deactivation, (3) high capital cost, (4) heat removal, and (5) less than optimum thermal efficiency. Significant progress toward the solution of deactivation, heat removal, and thermal efficiency problems has been realized in the past two decades; with these innovations improvements in process economics of 30–40% are realizable. Of perhaps even greater significance is the progress made during the same period in the understanding of the relationship of catalyst structure to activity and selectivity properties which provides a scientific basis for catalyst design. Some of the key recent improvements in FT catalyst, reactor and process technology which could significantly impact the efficiency and economical production of fuels and chemicals from coal and natural gas are summarized.