Simulation of Fixed Bed Reactor for Iron Catalyzed Fisher-Tropsch Reactor Using MATLAB /

Abstract

Demand for liquid fuel for more energy and rapid depletion of crude oil reserves, the importance of alternate energy has been increasing day by day. Fischer–Tropsch synthesis on a large scale is playing important role as a means for conversion of remote natural gas to high-quality products, particularly liquid transportation fuels. In order to give more reliable data about operating conditions and yield before bulk production this research is used to simulate the fixed bed micro reactor used for Fisher-Tropsch synthesis. In this work we have used the one dimensional heterogeneous model equations of energy and mass balance to investigate various parameters like hydrogen and carbon monoxide conversion, yield of hydrocarbons and CO2 production during water gas shift reaction as we considered iron based catalyst. Temperature and pressure along the length of fixed bed micro reactor is also investigated. Heat and mass transfer correlations are used to find out the design parameters and MATLAB code is made to utilize syngas as efficiently as possible. The results of this theoretical work revealed that the concentration of CO is decreased from 0.27 to 0.24, concentration of hydrogen from 0.7 to 0.58 and concentrations of hydrocarbons are increased along the length of the reactor. The temperature is increased from 573 to 573.6 K and pressure drop increased from 17 to 17.05 bars. Iron catalysts supported on silica, alumina and mixture of alumina and silica were prepared by incipient wetness impregnation method. Pore sizes of both the catalysts were established using BET and SEM characterization techniques. Fisher-Tropsch activity of these catalysts was evaluated by using 1-D heterogeneous model of fixed bed reactor under operating conditions of temperature 573K, pressure 17 bars and H/CO ratio 2.1. The CO conversion and higher hydrocarbons production was highest in SiO2 supported catalyst. This indicates that silica supported catalysts shows high FTS activity, higher water-gas shift reaction and higher selectivity to C5+ hydrocarbons and facilitates the CO adsorption. The FTS activity of both Al2O3 and SiO2/Al2O3 was very similar and lesser than SiO2.