2025 AIChE Annual Meeting

Post-Treatment Decoking after Direct CO2 Dissociation By Microwave Plasma

Direct CO2 dissociation by microwave plasma reactors offers a promising pathway for carbon capture and utilization. The reaction consists of splitting CO2 into CO and O2 molecules. During the destruction of carbon monoxide (CO) molecules into solid carbon, an unwanted build-up of carbon deposits, called coking, reduces the process efficiency and plasma stability. Thus, eliminating or reducing the coking effect during the CO2 conversion into solid carbon represents a crucial challenge.

This study investigates different strategies for remediating the coking on ceramic pellets. Here, pellets were intentionally coked under controlled plasma conditions and subsequently treated using various water and methanol-based solvent solutions under temperature-controlled sonication.

The post-treatment of the catalytic pellets using solution with a 1 wt% SDS surfactant additive has shown the highest yield of solid carbon recovery. The results were quantified by comparing the relative masses of coked carbon removed from the pellets, assuming the mass of coked carbon per unit mass of ceramic pellets remained consistent. These results demonstrate that a SDS surfactant-assisted methanol/water solvent mixture significantly improves the removal of coked carbon from ceramic pellets. This simple solution to the common issue of coking in the chemical engineering industry offers insight into an inexpensive and scalable alternative to existing decoking methods.