Effect of reaction conditions on the catalytic performance of Fe-Mn catalyst for Fischer-Tropsch synthesis

The effects of reaction conditions on the performance of an Fe-Mn catalyst for Fischer-Tropsch synthesis (FTS) have been investigated in a continuous spinning basket reactor. Experiments were carried out under a wide range of industrially relevant reaction conditions including reaction temperature of 533–573 K, pressure of 0.93–2.96 MPa, inlet H2/CO molar ratio of 0.80–2.50 and space velocity of (0.46–1.85) × 10−3 N m3 kgcat−1 s−1. The selectivities to low molecular weight hydrocarbons basically increased with the increase of reaction temperature, total pressure and inlet H2/CO ratio, except for ethylene. The FTS reaction rate and the overall oxygenates formation rate increased with increasing reaction temperature, pressure, space velocity and H2/CO ratio on the whole. It was found that the catalyst has relatively high activity and selectivity in producing light alkenes. It also exhibited excellent stability during the 700 h run at H2/CO ratio of 1.00, which indicates that the catalyst has good longevity and is suitable for syngas derived from coal with low H2/CO ratio to produce light olefins and high-quality liquid fuels. Meanwhile, it may have potential promising applications in advanced stirred tank slurry reactors. In addition, the detailed investigation of FTS reaction performance for the Fe-Mn catalyst can provide full and accurate basic information for industrial scale-up.

Graphical abstractThe H2/CO ratio in the reaction atmosphere plays a very important role in FTS reactions, which influences the selectivity of products directly. The higher H2/CO ratio is preferential for chain termination to produce light hydrocarbons while lower H2/CO ratio is preferential for the chain growth and the production of heavy hydrocarbons.Figure optionsDownload full-size imageDownload as PowerPoint slide