Modeling and Simulation of a PSA Process for CO2/Syngas Separation

This work aims to model and simulate a pressure swing adsorption (PSA) unit for CO2/syngas separation using rigorous multi-bed and single-bed approaches. The PSA unit was designed to purify syngas from reverse water-gas shift (RWGS) reaction to application in the Fischer-Tropsch synthesis. Process simulations were performed in Aspen Adsorption® v10 software, using the Peng-Robinson equation of state. The association of 7 adsorption beds was considered, allowing the continuous production of purified streams, in a concept of cyclic steady-state operation. The single-bed approach reduces the system complexity and improves the processing power/time without losing precision. A sensitivity analysis showed that integrated RWGS and PSA processes can produce syngas with purity above 94.65% with an H2/CO molar ratio of 1.50. The total recovery was around 99.98% and 99.57% for H2 and CO, respectively, for an adsorption pressure of 20.00 bar, and a desorption pressure of 1.50 bar.