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.
