Catalytic membrane reactor for the production of biofuels

The H₂-distributed feeding concept using Pd/Ag-based membranes and an Ru-based catalyst in a Packed Bed Membrane Reactor (H₂-PBMR) for the synthesis of biofuels via the so-called Fischer-Tropsch Synthesis has been demonstrated. The most successful approach resulted when H₂-poor syngas (H₂/CO = 1) typically obtained from the gasification of biomass was fed directly through the reaction chamber, i.e., to the catalyst bed, whereas the H₂ needed to reach the proper stoichiometry for the FTS (H₂/CO = 2) was admitted, and properly distributed, into the catalyst bed through the Pd/Ag-based membrane by flowing H₂/He mixtures at the retentate side of the membrane. Under the optimum reaction conditions, the CO conversion measured with the H₂-distributed feeding concept is lower than that obtained in a conventional Packed Bed Reactor with H₂/CO = 2 (37.9 vs 50.7%), but significantly higher than that obtained in a conventional reactor with H₂/CO = 1 (14.1%). Remarkably, the productivity towards high-molecular hydrocarbons increases by almost 70% and the methane production decreases by one order of magnitude when using the H₂-distributed feeding concept in a Packed Bed Membrane Reactor.