Sorbent Cost and Performance in CO₂ Capture Systems

TLDR

Power plants are key sites for CO₂ capture, typically using sorption–desorption cycles, and new sorbent formulations must handle the large carbon flows characteristic of these facilities. This study defines a mass‑balance parameter that indicates the minimum sorbent performance needed to keep sorbent‑makeup costs acceptable. The parameter is derived from a common mass balance applied to various capture processes, including absorption, adsorption, and high‑temperature chemical looping. Using monoethanolamine as a techno‑economic baseline, the analysis shows that many proposed sorbents would require laboratory testing over tens of thousands of cycles before being viable for power‑plant CO₂ capture.

Abstract

Power plants are prime candidates to apply CO2 capture for final storage as a mitigation option for climate change. Many CO2 capture concepts make use of a sorption−desorption cycle to separate CO2 from flue gas or O2 from air. These include commercial absorption processes, as well as processes using new sorbent formulations, adsorption, and high-temperature chemical looping cycles for CO2 and O2. All of these new processes must confront the large scale of carbon flows typical in a power plant. In this work, a common mass balance for all of these processes is used to define a parameter that highlights the minimum sorbent performance required to keep sorbent makeup costs at an acceptable level. A well-established reference system for which reliable commercial data exist (absorption with monoethanolamine, MEA) is used as a technoeconomic baseline to show that some of the sorbents being proposed in the open literature might need to be tested under laboratory conditions for tens of thousands of sorption−desorption cycles before they can be further considered as viable options for CO2 capture from power plants.