Numerical Simulation and Performance Analysis of Temperature Swing Adsorption Process for CO₂ Capture Based on Waste Plastic-Based Activated Carbon

The newly proposed activated carbon with excellent properties prepared by plastic waste as a precursor is an effective way to solve the problem of CO2 emission and solid waste plastic recycling. However, most of the analysis on the performance of this waste plastic-based activated carbon for the adsorption of CO2 in flue gas is only carried out at the level of material characterization, and the performance evaluation at the level of adsorption bed in the actual adsorption process is lacking. Therefore, in this study, a two-dimensional adsorption bed model is established using computational fluid dynamics method. And the effects of adsorption temperature, desorption temperature, inlet flow rate and porosity on the adsorption and separation performance of CO2 using waste plastic-based activated carbon are discussed. The results show that the CO2 purity and recovery of this waste plastic-based activated carbon adsorbent can reach 43.13 and 96.08%, and the productivity can reach 152.81 kg t–1 h–1 when the desorption temperature is 400 K. Comparing with the commercial adsorbent, the waste plastic-based activated carbon used in this study has certain adsorption advantages in terms of recovery and productivity. It can be further proved that waste plastic-based activated carbon can play a role as an efficient regeneration adsorbent at the CO2 capture level, and can promote negative CO2 emission at the same time. This study provides an important reference for the resource utilization of waste plastics and the development of CO2 emission reduction technology.