Effect of catalyst activity in SMR-SERP for hydrogen production: Commercial vs. large-pore catalyst

In this work, we have evaluated the performance of an SMR-SERP unit (steam methane reforming sorption enhanced reaction process), using two different Ni/Al₂O₃ catalysts: commercial “Octolyst 2001” from Degussa and a large-pore catalyst (Catalyst A). The selective CO₂ sorbent was a potassium modified hydrotalcites. Several experiments were performed under different operating conditions to validate a mathematical model.Experimental results show that the Degussa catalyst is more active and more selective to CO₂ producing hydrogen with higher purity and less CO than the large-pore catalyst. Cyclic SMR-SERP experiments were also performed. The cycles comprise four different steps: reaction, depressurization, reactive regeneration and pressurization. In the cyclic experiments, conversion was 43% higher than in an SMR reactor, while H₂ purity was 75%, which is 25% higher than in normal SMR operation. Results indicate that more active catalysts also promote a better reactive regeneration optimizing the use of part of the product (H₂). The proposed mathematical model was validated in a wide range of operating conditions and in a cyclic experiment. The model was able to describe the SMR-SERP experiments without any fitting parameters.