CO2 Capture from a Binary CO2/N2 and a Ternary CO2/N2/H2 Mixture by PSA: Experiments and Predictions

The results of pressure-swing adsorption experiments performed in a two-column setup are presented, as a way of validating a model developed to design and optimize cyclic adsorption processes. The experiments were conducted using a commercial activated carbon as the sorbent and an adsorption pressure of 20 bar. Two feed mixture compositions were studied: a binary CO2/N-2 mixture representative of a flue gas and a ternary CO2/N-2/H-2 mixture representative of the product stream of air-blown autothermal reformers. During the experiments, the temperature was measured at five locations along the center of each column, along with the pressure, feed flow rate, product composition, and high-pressure product flow rate. A one-dimensional, nonisothermal, nonequilibrium model was used to simulate the experiments in a fully predictive manner. This model was previously validated in breakthrough experiments as well as PSA experiments using a binary CO2/H-2 mixture. A thorough analysis of the experimental results and comparison with the simulation results showed that the model is fully capable of handling rather different feed compositions while still predicting satisfactorily the temperatures within the column, the product composition, and the overall process performance for a variety of process configurations and operating conditions.