Improved hydrogen production from dry reforming reaction using a catalytic packed-bed membrane reactor with Ni-based catalyst and dense PdAgCu alloy membrane

A catalytic Pd76Ag19Cu5 alloy membrane reactor packed with 5% Ni/Ce0.6Zr0.4O2 catalyst was adopted in this study to investigate hydrogen production performance from the dry reforming reaction of methane and carbon dioxide. The 1:1 CH4/CO2 feed was introduced to the reactor with 60 mg of the catalyst at a flow rate of 20 ml/min at 550 °C. The effluent gas compositions were examined using an online gas chromatographer (GC). Compared to a conventional reactor without the membrane, the CH4 and CO2 conversions were significantly increased by 3.5-fold and 1.5-fold, respectively. Correspondingly, the overall H2 yield was greatly improved from about 10-35%. Additionally, the hydrogen selectivity increased from 47 to 53%. It is theorized that the in-situ partial hydrogen withdrawal by the membrane mainly caused the dry reforming reaction equilibrium to shift forward and created a hydrogen-deprived environment unfavorable for the competing reversible water-gas shift reaction to take place.