Modular monolith adsorbent systems for CO2 capture and its parameterized optimization

Abstract

A key challenge for power plant carbon capture systems is operating economically under varying load conditions. Daily variations may be handled through control systems with reduced economic performance, but longer term seasonal cycles will require different solutions to enable robust and economic operation. We propose to use modular monolith adsorbent (MMA) designs whose capacity and configuration can be altered to respond to variations in flue gas flow. The configuration of the blocks is defined by the pattern of their serial and parallel connection. The ability to present a shorter, but wider, bed at different flue gas flowrates can then be exploited to improve performance and continuing to meet constraints on product purity and recovery. This additional degree of freedom afforded by the modular nature of the design allows an active response to the flowrate conditions and increases the flexibility of the system over the space of flowrate and concentration. In order to compare the proposed MMA systems and the conventional passive design method, case studies with varying flue gas amounts in a power plant are carried out. Simulation results show that the proposed MMA systems have improved optimal solutions because of their design flexibility, compared to the conventional passive design approach. Lastly, the optimized solutions are presented as a parametric map with different CO2 capture fractions and flowrate of flue gas. These parametric off-line solutions can be a guideline for the process implementation and reduce the operating complexity even if the MMA systems are used.