Role of water-gas-shift reaction in Fischer–Tropsch synthesis on iron catalysts: A review

Abstract

Water-gas-shift (WGS) reaction plays a significant role in industrial application of Fischer-Tropsch synthesis (FTS) for coal-to-liquid (CTL) processes with iron-based catalysts. This reaction provides necessary hydrogen for synthesis gas with low H2/CO molar ratio, and has influence on concentrations of reactants, water and carbon dioxide, which in turn has effect on product distribution, rate of FTS and catalyst deactivation. We provide information on the effect of process conditions (H2/CO feed ratio, reaction temperature and pressure), syngas conversion, and catalyst composition and activation procedure on the WGS activity. H2/CO consumption (or usage) ratio and the exit H2/CO ratio vary with conversion and the extent of WGS reaction. The extent of variation is much greater for H2/CO feed ratios greater than 1.7, than it is for the CO rich syngas (H2/CO = 0.5-1). This in turn places limits on maximum practical single pass conversion which can be achieved with different feed compositions and results in different types of operation (low single pass conversion with tail gas recycle, and high once through single pass conversion).

The Synergy Effect of Ni-M (M = Mo, Fe, Co, Mn or Cr) Bicomponent Catalysts on Partial Methanation Coupling with Water Gas Shift under Low H2/CO Conditions

“…Hence, from the standpoint of safety and efficiency, a series of requisite processing technologies has to be employed in order to eliminate the above two drawbacks before it is transported through a pipeline to downstream users. As is well known, water gas shift (WGS) (Equation (1)) is highly efficient to adjust the H 2 /CO ratio by converting CO with H 2 O to CO 2 and H 2 [7]. In addition, methanation (Equation (2)) as one type of CO hydrogenation reaction is capable of reducing CO content and in the meantime generating CH 4 that is of high heating value and innocuity.…”

Is the Fischer-Tropsch Conversion of Biogas-Derived Syngas to Liquid Fuels Feasible at Atmospheric Pressure?

“…The competing selectivity of CH 4 and C 5+ in R4 suggested a deviation from ASF. Previous research [60][61][62][63] proposes that this may be due to the presence of two chain growth probability α values that characterize the catalyst in use. The existence of two sites on the catalyst surface suggests that each site might independently yield the ideal ASF [59].…”

Deactivation Model for an Industrial γ‐Alumina Supported Iron Catalyst in the Fischer Tropsch Synthesis

“…Catalyst deactivation is a major industrial problem since it is not cost‐effective to stop the process for replacing the catalyst ,, . Iron catalysts lose their activities during the FTS due to several deactivation mechanisms such as poisoning, carbon deposition, sintering, and oxidation Sulfur is known to be poisonous to catalytic compounds because of the presence of molecules that are found in biomass and coal…”