Optimal synthesis and design of solvent-based PCC process using a rate-based model

Solvent-based post-combustion carbon capture (PCC) technology though being the best available option for large-scale carbon capture and sequestration (CCS) projects, faces the drawback of high energy intensity and large capital cost. Therefore, process optimization plays a key role in further improvement of the performance efficiency and curbing the costs. The PCC technology involves complex reactive separations for which achieving the goal of an optimized process requires existence of a rigorous design methodology considering both operation and design parameters. In this paper, an equation-based methodology is developed for optimal synthesis and design of absorption and desorption columns considering rate-based interaction of the gas and liquid. The design methodology considers all the influential techno-economic parameters such as number of absorber/desorber columns, height and diameter of columns, operating conditions (P, T) of columns, pressure drop, packing type, percentage of CO2 avoided, captured CO2 purity, amount of regeneration, and flooding velocities of columns. An example is solved for a 300 MW coal-fired power plant and numerous parametric analyses are performed using 30 wt% monoethanolamine (MEA) solvent. The parametric study shows that the design and operation parameters are markedly interactive, and that a successful solvent-based PCC design requires concurrent consideration of both aspects. (C) 2014 Elsevier B.V. All rights reserved.