Development of Hybrid Fischer-Tropsch Synthesis Catalysts for Direct Production of Synthetic Gasoline from Coal-Based Syngas: An Indonesian Perspective

Abstract

The Fischer-Tropsch Synthesis (FTS) represents an environmentally friendly method for producing liquid fuelfrom coal-based syngas via the hydrogenation of carbon monoxide. In order for such a process to be feasible,better catalysts that are capable of enhancing the reaction performance are required. In response to these needs,new catalysts were investigated and introduced in this work. The incorporation of zeolite into the iron based FTScatalyst was expected to help refine the hydrocarbon products and shift the product distribution from the typicalFTS product range to the middle iso-paraffins, which is a gasoline range, and eventually increase the yield of theliquid fuel. This study aims to develop catalyst for producing liquid fuel, particularly gasoline, from carbonmonoxide and hydrogen. The pH of the catalysts was found to have significant effect on the catalytic activity dueto its ability to control the amount of promoter to be precipitated in the catalyst, which results in a lowerreduction temperature. Physically mixing the iron based FTS catalyst with zeolite was found to have little effecton the catalytic activity and the product distribution, apart from slightly increasing the selectivity of iso-paraffins,which is the indication of isomerization activity. Coating of zeolite onto the iron based FTS catalyst to form acore-shell structure was intended to enhance the ease of migration of the reactant and thus increasing thecatalytic activity and shifting the product distribution towards the gasoline range. While zeolite shell has beensuccessfully coated uniformly on the iron based core using hydrothermal synthesis technique, the formation ofthick zeolite shell might have blocked the active FTS sites on the iron based catalyst to some extent and isbelieved to have contributed to the low activity of the core-shell catalyst.