Upgrading of Simulated Syngas by Using a Nanoporous Silica Membrane Reactor

The permeance properties of a nanoporous silica membrane were first evaluated in a laboratory-scale porous silica membrane reactor (MR). The results indicated that CO, CO₂, and N₂ inhibited H₂ permeation. Increased H₂ permeability and selectivity were obtained when gas was transferred from the lumen side to the shell side. This was therefore selected as a suitable permeation direction. On this basis, upgrading of simulated syngas was experimentally investigated as a function of temperature (150-300°C), feed pressure (up to 0.4MPa), and gas hourly space velocity (GHSV), by using a nanoporous silica MR in the presence of a Cu/ZnO/Al₂O₃ catalyst. The CO conversion obtained with the MR was significantly higher than that with a packed-bed reactor (PBR) and broke the thermodynamic equilibrium of a PBR at 275-300°C and a GHSV of 2665h^-1. The use of a low GHSV and high feed pressure improved the CO conversion and led to the recovery of more H₂. Upgrading of simulated syngas was investigated by using a nanoporous silica membrane reactor. Increased H₂ permeability and selectivity were obtained when gas was transferred from the lumen side to the shell side. In the membrane reactor, the CO conversion broke the thermodynamic equilibrium.