Enhanced single-loop control of a moving bed temperature swing adsorption CO2 capture process

Abstract

Using a model in gPROMS, we study a Zeolite 13X-based moving bed temperature swing adsorption (MBTSA) process designed to capture CO₂ from a coal-fired power plant. Two enhanced single-loop control strategies were compared to a proportional-integral configuration for variations in power plant load, control variable setpoints, flue gas CO₂ concentration and external heat source temperature. Measurement delays were also investigated. Adaptive adjustment of controller parameters with system load gave smoother and narrower manipulated variable profiles and efficient CO₂ recovery setpoint tracking. The controller gain is the most important parameter for adaptive tuning. A combined feedback and feedforward scheme showed improved control of the regenerated sorbent temperature, possibly due to better decoupling of the higher-level control loops. When delays were considered, the investigated strategies significantly outperformed the reference case for CO₂ recovery control. The results demonstrate that the MBTSA process can be efficiently controlled for several disturbances and changes in operation.