Adsorption heat/mass conversion cycle for carbon capture:Concept, thermodynamics and perspective

Adsorption cycles have been widely used for the low-grade thermal energy recovery of heating, cooling, energy storage and power in the past few decades. However, thermal cycles for adsorption carbon capture gradually draw more attention since the adsorbate is regarded as the key product. To make an analogy among different adsorption cycles based on their common characteristics, a generalized concept of adsorption heat/mass coupled cycle is initially proposed and analyzed for carbon capture in this perspective. Several representative working cycles are first introduced in terms of temperature swing adsorption, pressure swing adsorption and the hybrid working process. Then, the key performance indicator, the specific heat consumption of the capture cycle, is provided to illustrate current status and barriers of adsorption carbon capture technologies. To address the issue of energy penalty, several solutions are provided from the thermodynamic aspects at three progressive levels, i.e., internal heat and mass recovery for common capture cycles, heat pump-assisted adsorption carbon capture, and capture through energy integration in the whole industrial plant. Visions for future applications are combined to provide a holistic perspective for the improvement of energy utilization of carbon capture technologies.