Clustered carbon capture as a technologically and economically viable concept for industrial post-combustion CO2 capture

Abstract

Industrial CO2 emission is a primary contributor to the global warming and as such an accelerator of the climate crisis. Countries worldwide have adopted the 'Paris Agreement' to restrict the global temperature rise below 2 degrees C, and ideally below 1.5 degrees C compared to the pre-industrial levels. Reactive absorption which utilizes aqueous alkanolamine solvents in an absorption and stripping column tandem is the current de-facto standard for a realistic, industrial-scale, post-combustion carbon capture. The solvent regeneration and high concentration CO2 release in the stripping column represents the bulk of the process's operating cost, due to high energy requirement of the reboiler unit ( 4-10 GJ / ton CO2). This fact alone makes the process prohibitively expensive in both energy and economic terms for many major CO2 emitting entities such as fossil fuel power plants, cement producers, refineries, etc. To address this issue in this work we present a new process topology concept entitled Clustered Carbon Capture. A cluster of major CO2 point sources in a variable radius all with CO2 absorption columns of appropriate scale share a centralized stripper column appropriately sized to regenerate the solvent for all the points in the cluster. As a proof-of-concept this work has 3 sources (300-2,000 MW coal power plants) and a 35 km radius. Utilizing the economies of scale on the most expensive and energy intensive unit our expected results should quantify the amount of cost reduction for the CO2 capture for each individual point of the cluster. Provided that the cost reduction is significant, clustered carbon capture might well represent an indispensable strategy for economic CO2 reduction on a large-scale, utilizing an already proven technology.