(521d) Sorbent Development for Microwave-Accelerated Regeneration of a Slurry (MARS) Process for Carbon Capture

Solvent regeneration is the most energy- and cost-intensive operation in aqueous amine-based capture processes. It often requires a large amount of superheated steam to raise the bulk temperature typically above 120 °C for reactive regeneration. This limitation leads to slower and inefficient capture/release stages that also hinder large-scale utilization.

In this work, a slurry of basic immobilized amine sorbent (BIAS) and polydimethylsiloxane (PDMS) oil has been developed for a CO₂ adsorption/desorption process aided by the Microwave (MW)-Accelerated Regeneration of a Slurry (MARS). Using non-aqueous silicone oil can minimize water use and also reduce the energy penalty for slurry regeneration because silicone oil has a much lower heat capacity but a higher boiling point than water. Previously, studies indicated that selective MW heating of CO₂-adsorbed BIAS can increase the CO₂ desorption flux by 10 times in comparison with thermal heating and may consume much less energy for CO₂ desorption, even at process temperatures of 65-85°C. In order to enhance the energy efficiency, the sorbent was modified by adding trace amount of MW-favored nano-materials to promote selective absorption of MW energy. Improved CO₂ desorption kinetics will be reported.