Membrane Reactors for the Fischer-Tropsch Synthesis

The analysis of the specific features of the Fischer-Tropsch synthesis helps formulating the most important requirements to the FTS reactor. Membrane reactor designs can be useful for the FTS process application. Semi-permeable hydrogen-selective distributors allow to control the H2:CO ratio along the catalyst bed and thus enhance the selectivity of the process. Membranes of extractor type can help to improve the FTS performance by selective removing water from the reaction volume. On the other hand, plug-through contactor membrane reactor design (PCM) seems to meet all the other requirements, ensuring the high concentration of the catalyst, isothermicity, high gas-liquid interface area, small effective diffusion length and reasonable hydraulic resistance. Varying the membrane composition and conditions of its preparation leads to the changes in porous structure parameters of the PCM membrane. This allows to weaken the diffusion constrains in a predictable way and, therefore, to control the productivity and selectivity of the Fischer-Tropsch process.