Effect of Pressure, H2/CO Ratio and Reduction Conditions on Co–Mn/CNT Bimetallic Catalyst Performance in Fischer–Tropsch Reaction

Abstract

The effects of process conditions on Fischer–Tropsch Synthesis (FTS) product distributions were studied using a fixed-bed microreactor and a Co–Mn/CNT catalyst. Cobalt and Manganese, supported on Carbon Nanotubes (CNT) catalyst were prepared by a Strong Electrostatic Adsorption (SEA) method. CNT supports were initially acid and thermally treated in order to functionalize support to uptake more Co clusters. Catalyst samples were characterized by Transmitted Electron Microscope (TEM), particle size analyzer, and Thermal Gravimetric Analysis (TGA). TEM images showed catalyst metal particle intake on CNT support with different Co and Mn loading percentage. Performance test of Co–Mn/CNT in Fischer–Tropsch synthesis (FTS) was carried out in a fixed-bed micro-reactor at different pressures (from 1 atm to 25 atm), H2/CO ratio (0.5–2.5), and reduction temperature and duration. The reactor was connected to the online Gas Chromatograph (GC) for product analysis. It was found that the reaction conditions have the dominant effect on product selectivity. Cobalt catalyst supported on acid and thermal pre-treated CNT at optimum reaction condition resulted in CO conversion of 58.7% and C5+ selectivity of 59.1%.

Effect of Temperature, Syngas Space Velocity and Catalyst Stability of Co-Mn/CNT Bimetallic Catalyst on Fischer Tropsch Synthesis Performance

“…Some researchers recorded the influence of operating conditions on the product selectivity for cobalt-based catalysts [20,24,25] and revealed that the olefin selectivity of the hydrocarbon product range reduced with rising pressure, which has reported in prior studies [19,21,24]. This study is a continuation of previous research that has been examined and published [26][27][28][29][30]. The current investigation aims to prepare cobalt manganese bimetallic catalysts on CNT substrate employing SEA technique, also to study effects of temperature, syngas space velocity, and catalyst stability through Fischer-Tropsch synthesis by performing Co-Mn/CNT bimetallic catalyst.…”

Highly Efficient ZIF-67-Derived PtCo Alloy–CN Interface for Low-Temperature Aqueous-Phase Fischer–Tropsch Synthesis

“…It is further proposed that the concentration of the reactants increases over the surface of the catalyst with increasing pressure, which improves the adsorption of CO on the catalyst surface and enhances the chances of collision between reactants and catalysts . Various studies have reported the effect of pressure on the selectivity of methane, where methane production decreases with increasing reactant pressure. , Nonetheless, in the present case, it was observed that the selectivity of methane increases when the reactant pressure is changed to 4 MPa, which is likely due to the dominating effect of high CO conversion at high pressure, which further increases the H 2 /CO ratio and favors methane production …”

“…71 Various studies have reported the effect of pressure on the selectivity of methane, where methane production decreases with increasing reactant pressure. 72,73 Nonetheless, in the present case, it was observed that the selectivity of methane increases when the reactant pressure is changed to 4 MPa, which is likely due to the dominating effect of high CO conversion at high pressure, which further increases the H 2 / CO ratio and favors methane production. 67 The effect of reaction time (1−20 h) on the selectivity of CO 2 , CH 4 , C 2 −C 4 , and CO conversion is shown in Figure 8d.…”

Syngas Solubility in the Liquid Phase of the Fischer‐Tropsch Synthesis

“…The bulk of other works [35][36][37][38] report that in FTS at low H 2 /CO ratios the selectivity moves to longer-chain hydrocarbon products as the total pressure increases. Similarly, Figs.…”