Catalytic membrane reactor for the production of biofuels

• B-Ru/TiO2 is very active catalyst for the production of biofuels via FTS.
• Pd/Ag membranes have high hydrogen permeation and resistance to embrittlement.
• H2 is well distributed along the catalytic bed in PBMR using Pd–Ag membranes.
• Under appropriate conditions, hydrocarbon production is higher in PBMR than in PBR.

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.

Figure optionsDownload high-quality image (121 K)Download as PowerPoint slide