Novel short-cut estimation method for the optimum total energy demand of solid sorbents in an adsorption-based CO2 capture process

In solid-sorbent CO2 capture, CO2 desorption is ordinarily carried out at high temperatures with or without a vacuum. The strategy and specific conditions for CO2 desorption are determined from an economic point of view and depend entirely on the characteristics of the adsorbent. In this study, we propose a semi-graphical short-cut method that enables easy estimation of the minimum energy demand for capturing unit amount of CO2 together with associated optimum process operating conditions. Our method uses only the most basic properties of the adsorbent such as the adsorption equilibrium and kinetic information and heat capacity. The proposed short-cut method was numerically investigated and evaluated for a set of seven adsorbents: three physical adsorbents and four chemical adsorbents. Compared with the results of the conventional rigorous model, highly accurate predictions were obtained from the proposed short-cut method. The short-cut method enables the rapid and accurate screening of sorbents, which will ultimately accelerate the development of economically deployable CO2 capture processes based on solid sorbents.