Combined synthesis and hydroprocessing on a cobalt catalyst on a cobalt-containing zeolite catalyst

Abstract

A composite Co-Al2O3/SiO2/HZSM-5 catalyst has been developed for one-step synthesis of fuel series hydrocarbons from CO and H2. The catalyst was obtained by mixing and forming powders with a Co-Al2O3/SiO2 catalyst, zeolite HZSM-5, and boehmite Al(O)OH?H2O. The physicochemical methods XRD, PEM, BET established the phase composition of the catalyst, the particle size of cobalt (8.2 ± 1 nm), its specific surface area (286 m2/g). Tests were carried out in the synthesis of hydrocarbons from CO and H2 for 60 hours at a temperature of 240 ° C, a pressure of 2.0 MPa, and a gas flow rate of 1000 h-1. It is shown that synthesis gas diluted by 40% with nitrogen can produce liquid C5+ hydrocarbons with a selectivity of 69% and a productivity of 81 kg/(m3?h). The yield of С5+ hydrocarbons was 70 g/m3 of the leaked synthesis gas and 135 g/m3 of the converted synthesis gas. Synthetic oil has a molecular mass distribution close to monomodal (the probability of chain growth is 0.81), 88% consists of gasoline and diesel fractions and 12% of long-chain C19+ hydrocarbons. The ratio of isomeric hydrocarbons to normal hydrocarbons (iso/n) is 1,26, and the ratio of olefinic hydrocarbons to paraffinic hydrocarbons is 0,97. In the gasoline fraction of hydrocarbons (C5-C10), a high content of alkenes of normal and branched structure (76,3%) is noted, the proportion of iso-alkanes and n-alkanes is 10,8 and 12,9%, respectively. The catalyst showed stable operation, the rate of its deactivation is comparable to the rate of deactivation of a commercial bifunctional catalyst.