R E Yakovenko, A P Savost’yanov, N S Chistyakova, V G Bakun and S I Sulima

Platov South-Russian State Polytechnic University (NPI), 132, Prosveshcheniya street, Novocherkassk, 346428, Russia

Abstract

Three stages of extraction of the contents of the porous space of cobalt catalysts, continuously operating for different periods of time (Time on stream (TOS) is from 40 to 800 h) in a Fischer-Tropsch fixed bed reactor, were performed to identify carbon-containing compounds using chromatographic analysis. At each stage of extraction, the surface of the samples under study was investigated by SEM and BET methods. It was determined that during operation, as a result of accumulation of linear alkanes in the pores of the catalyst with an average number of carbon atoms from 20 to 25 and a decrease in the specific surface area, the reaction rate reduces by 25-30 %. With the help of oxidative treatment, it was found that elemental carbon is contained in the porous space of the spent catalysts.