Decarbonised H2 recovery and CO2 capture using a cost-effective membrane plant: A step towards energy transition

Separation of H2 from CO2 is crucial in industry, since they are the products of water gas shift reaction. In addition, the demand for pure H2, as well as the potential reuse of CO2 as reactant, are increasing as a consequence of the transition from fossil fuels to decarbonization processes. In this scenario, this work aims to propose a possible solution to get simultaneously pure H2 and CO2, meeting the world's requirements in terms of reduction of CO2 emissions and transition to cleaner energy. A simulated plant combining Pd-based and SAPO-34 membrane modules is able to provide pure H2, with a final recovery higher than 97%. In addition, the entire CO2 fed to SAPO-34 unit is recovered in the permeate stream, with a concentration of 97.7%. A cost analysis shows that feed gas gives a higher contribution than compression, heat exchange and membranes (e.g., 70, 20, 3 and 7% respectively). Net profit and net present value are positive within a specific feed gas price range (e.g., net profit up to 0.10 and 0.155 $/Nm3, depending on the labour cost set), showing that the process can be cost-effective and profitable. H2 purification cost ranges between 2.6 and 7.8 $/kg.