Assessment and optimization of SF6 recovery from SF6/N2 mixture via temperature swing adsorption cycle

Abstract

Sulfur hexafluoride (SF₆) is a powerful greenhouse gas. However, the existing studies primarily employ the pressure swing adsorption cycle or vacuum swing adsorption cycle for SF₆ recovery and tend to focus on a single performance indicator, thereby lacking a comprehensive assessment of the adsorption cycle across multiple dimensions. In this paper, the temperature swing adsorption (TSA) cycle model is constructed. Six performance indicators are selected for sensitivity analysis. A comprehensive assessment of SF₆ recovery using TSA cycle is conducted, focusing on the dimensions of production, separation, and energy efficiency. The multi-objective optimization is further performed. The aim of this work is to explore the feasibility of recycling SF₆ via the TSA cycle. Results indicate that the Toth model demonstrates the superior fit with R² of 0.9991. There is a positive correlation between the recovery and the purity, while the exergy efficiency displays a competitive relationship with recovery and the purity. Based on the TOPSIS decision-making method, the optimal values for the adsorption temperature and desorption temperature are found to be 293.00 K and 373.56 K, respectively. Under this operating condition, the recovery, purity, and exergy efficiency are achieved at 86.13 %, 98.69 %, and 2.70 %, respectively.