Dual-reflux pressure swing adsorption process for carbon dioxide capture from dry flue gas

This work presents a detailed experimental and simulation study for capturing and recovering high purity carbon dioxide from a dry flue gas (15%CO2/85%N2) via a laboratory-scale dual-reflux pressure swing adsorption apparatus using silica gel as an adsorbent. To achieve a favorable carbon capture performance, parameter study was implemented to obtain a series of optimized settings of process operating variables by investigating the effects of flowrate of light product reflux, flowrate of heavy product and feed inlet position on the separation performance in terms of product purity, product recovery, and adsorbent productivity, as well as specific power-consumption. Under the optimal manipulation parameter configuration, a high-purity CO2 product with a concentration of 95.55% and a higher CO2 product recovery of 96.81% with a competitive specific power consumption of 110.58 kJ mol−1CO2 can be obtained. This finding demonstrated an efficient and economical method in the field of carbon capture and storage. In addition, a good consistency between simulation results and experimental data confirmed the reliability of the mathematical model of dual-reflux pressure swing adsorption process, and the dynamic distribution behaviors of pressure, temperature and gas-solid concentration were obtained from the simulation results to illuminate and validate the process separation performance in depth under different operating conditions.