(400g) Process Simulation and Optimization of Pressure Swing Adsorption for Carbon Monoxide Separation

An exhaust gas from still mill plant which is one of the by-product gases generated in steelmaking process contains CO, CO₂, N₂, and H₂. Currently, this gas is used for power generation; however, due to its low calorific value, it is classified as a high-carbon-emission process. Therefore, by capturing CO₂ and CO, it is possible to not also reduce greenhouse gas emissions but also utilize CO and CO₂ as chemical feedstocks. We developed a novel adsorption process primarily targeting the adsorption of CO and CO₂ over N₂ and H₂.

A CO purification process was developed using Cu-loaded sorbent. The VPSA process was applied for CO separation. Using this model, we designed the VPSA process based on the modified Skarstrom Cycle. This cycle includes pressurization, adsorption, blowdown, desorption, In order to find out the mass transfer resistance, single-component and binary breakthrough adsorption experiments were conducted and the mass transfer rate was estimated to simulate the VPSA process. From this model, the nominal condition of VPSA process was synthesized. The process performance such as recovery, purity, and productivity will be reported. After constructing this model, multi-objective optimization based on PSO (Particle Swarm Optimization) was conducted. The nominal conditions of VPSA process as decision variables to the dependent variables are set based on SHapley Additive exPlanations (SHAP) method. The results of optimization are aimed for minimizing energy consumption and maximizing CO recovery rate. In the progress of optimization, feasible regions were considered and calculated based on the reinitialization velocity variation on the algorithm and Euclidean distance.

We obtained several Pareto Frontier Curves for the multi-objective optimization results regarding CO purity and recovery rate and energy consumption. Through this, we identified the region where CO purity and recovery rate exceed 90%, and developed a VPSA process for CO purification through process optimization.