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 ℃, and ideally below 1.5 ℃ 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.