A Systematic Simulation and Proposed Optimization of the Pressure Swing Adsorption Process for N2/CH4 Separation under External Disturbances

• Published in: Industrial & engineering chemistry research Vol. 54; no. 30 p.7489-7501; pp. 7489 - 7501
• Main Authors: Sun, Weina, Shen, Yuanhui, Zhang, Donghui, Yang, Huawei, Ma, Hui
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.08.2015
• Subjects: activated carbon; adsorbents; adsorption; algorithms; engineering; methane
• ISSN: 0888-5885; 1520-5045; 1520-5045
• DOI: 10.1021/acs.iecr.5b01862

This work presents a detailed study of the systematic simulation, optimization, and control of a pressure swing adsorption (PSA) process that used activated carbon as adsorbent to recover CH4 from a gas mixture (70% N2/30% CH4). The state-of-the-art reduced space successive quadratic-programming (r-SQP) optimization algorithm is employed to find the optimal values of the decision variables with additional constraints. The best closed loop recovery obtained for the PSA system under consideration is around 98% with purity of 80%. The control strategy is based on the regulatory proportional–​integral–​derivative (PID) controller because of its practicability and stability. Additional constraints that guaranteed the flexibility and adaptability of the PID controller were imposed on the optimization-based PSA system. The ability of the control system to reject various disturbances was evaluated and compared with the open loop conditions. Results demonstrated that the well-designed control system showed a wonderful performance in the presence of multiple disturbances.