(185b) Modeling of Electrothermal Reactor for Carbon Capture Using Electric Swing Adsorption

The escalating concerns over rising carbon footprints and global temperatures underscore the urgency of minimizing greenhouse gas emissions through methods like post-combustion carbon capture using adsorption processes. Traditional approaches to CO₂ Capture and Utilization (CCU) involve carbonation (capture) on solid sorbents, followed by regeneration and then transportation of CO₂-rich feeds for transformation into high-value chemicals. For desorbing captured CO₂, temperature or pressure swing adsorption processes are commonly used, yet these methods face scalability challenges due to their substantial energy requirements and the necessity for large-scale separation units. In contrast, Electrothermal Integrated CO₂ Capture and Utilization (e-ICCU) offers a more energy-efficient solution by leveraging joule heating (resistive heating of conductors) to heat dual-functional materials (catalyst-sorbent) for CO₂ desorption, then directly converting it to high-value chemicals within a single reactor system. This approach negates the need for the purification and transportation stages associated with captured CO₂. This study introduces a one-dimensional electrothermal reactor model, designed in gPROMS, featuring a Ni-CaO catalyst-sorbent on a SiC mesh (an electrically conductive carrier) for capturing and desorbing CO₂ from flue gas using Joule heating. The model applies a rigorous first-principles process to derive mass-energy balance equations and employs finite element modeling to determine the concentration and temperature distributions across the catalyst-sorbent bed. Utilizing experimental data from a novel laboratory-scale electric reactor, we assess the accuracy of our simulated model, which integrates multiple physical phenomena, specifically diffusion and thermal conduction. This model sheds light on the fundamental processes involved in joule heating of composite materials and CO₂ capture using the electric reactor. It enables the optimization of variables such as joule heating input, reactor design, and sorbent-catalyst loading, aiming to enhance energy efficiency and maximize conversion yields. The future goal of the model aims to integrate a reaction scheme for the catalyst-sorbent using joule heating to convert captured CO₂ to syngas.