Investigating the feasibility of valorizing residual char from biomass gasification as catalyst support in Fischer-Tropsch synthesis

Abstract

In spite of its remarkable properties and similarities to more traditional activated carbon (AC), biomass gasification char is considered a worthless material and treated as an industrial waste. However, similar to AC, char could be valorized in several applications. This study investigates the application of char as catalyst support for Fischer-Tropsch (FT) synthesis. For this purpose, char derived from a biomass gasifier operating in South Tyrol, Italy, was collected, characterized, acid treated and used as support for the catalysts preparation. Cobalt and iron were used as active metals and impregnated on char with a 10% metal loading (10Co and 10Fe). Catalysts were characterized through different techniques. FT tests were run in a fixed bed reactor operating at T = 240 °C, p = 1.6 MPa, H2/CO = 2, WHSV = 3600 mL g−1 h−1.10Fe was also tested at 250 °C. Catalysts performances in terms of CO conversion, CH4 and CO2 selectivity, and product distribution were analyzed and compared. The highest CO conversion (26%) was measured for 10Fe at 250 °C. For 10Fe, C1 - C22 hydrocarbons were detected, while for 10Co also C22 - C24. Only production of C13 - C19 was superior for 10Fe than 10Co.