Simulação da Síntese de Fischer-Tropsch em Reator Tubular de Leito Fixo com Catalisador de Ferro

Abstract

The Fischer-Tropsch synthesis is a technology from the 1920s created by Franz Fischer and Hans Tropsch in Germany that is still studied in this century due to its potential to produce green fuels and chemicals. It consists basically of the passage of a gaseous mixture of H2 and CO, the syngas, through a catalytic bed, producing hydrocarbons and water in the main reaction. The secondary reaction, water-gas shift, forms H2 and CO2 from CO and H2O. This work proposes the modeling and simulation of this synthesis, in a fixed bed tubular reactor, with iron based catalyst, aiming to evaluate the influence of the total pressure and the H2/CO proportion in the product distribution and the CO conversion. The influence of the presence of water in the beginning of the reactor, as an initial condition was also evaluated. The modeling included the simultaneous occurrence of the alkyl and alkenyl mechanisms, as well as a rate law well established in the field. In general, the simulation results showed great selectivity for olefins, specially ethylene. It was shown that raising the total pressure favors product formation, but decreases the conversion; an increase in the H2/CO proportion raises the conversion and the formation of all products, but CO2; and the presence of water as an initial condition compromises the reaction yield, lowering the conversion and the formation of the products, except for paraffins