Optimization and heat integration of hollow fiber based thermal swing adsorption process for CO2 capture from flue gas

Abstract This work studies the optimization of a hollow fiber contactor operated in a rapid temperature swing adsorption (RTSA) mode for CO 2 capture from flue gas. A hollow fiber contactor enables rapid heat and mass transfer and an efficient heat integration whereby parasitic loads on power plants can be reduced significantly compared to the traditional thermal swing adsorption processes. In this paper we employ a dynamic optimization strategy to predict the optimal operating conditions of a hollow fiber RTSA process for different process design objectives. The objective function considered was to maximize the feed throughput of the process with constraints for the required CO 2 purity and recovery. Furthermore, the external heat and cold utilities must be minimized. The optimization requires a dynamic heat integration i.e. redistributing the hot and cold stream outlet between different parts of a cycle which is challenging and unconventional. This has been performed using a binary decision variable which switches the outlet water stream between hot and cold tanks. We also show that a multi- objective optimization approach can be employed to determine the optimal trade-off between heat duty and process throughput. Optimization was performed using a single discretization approach within gPROMS.