(162f) CO2 Conversion to Syngas Coupled with a Membrane Separation: Multi-Scale Modeling and Simulation.

Fossil fuels continue to become the major energy sources around the world. About 6,870 million metric tons (MMT) of greenhouse gas are emitted into the atmosphere each year because of the fossil fuels-based energy production actions, over 80% of which is in the form of CO2. As a result of this process, the world is facing the serious environmental problems, and, thus, reducing the carbon emissions has become an urgent issue. The reverse water gas shift reaction (RWGS) has garnered significant interest as a possible method for the broad usage of CO2 by generating synthesis gas. The reverse water gas shift (RWGS) reaction is a promising method for converting CO2 and H2 into CO and water. The resulting CO can then be utilized in downstream Fischer-Tropsch (FT) or MeOH synthesis processes. Nevertheless, because the RWGS reaction is endothermic, it necessitates elevated temperatures in order to attain equilibrium CO2 conversions.

Integration of multiple operations (e.g., reaction and separation) in a single unit is a robust tool to improve the existing process’ efficiency, reduce energy consumption, and unwanted outputs/by-products. Such intensification has the potential to enhance process efficiency/economics by offering drastic process technologies improvements, regarding a variety of metrics to accomplish such intensification, PI encompasses several techniques such as adsorption, absorption and membranes. Especially, membrane reactor (MR) receives considerable attention to removal, and recovery of the produced gases from fuel gas. The reaction products is selectively removed by the membrane, so the equilibrium is shifted to the product side, enabling higher conversions and the produced gas capture processes to be combined in one single step. Operating at lower reaction temperatures, reducing material costs, increasing operation safety, eliminating the need for excess steam in the reaction, minimizing the need for downstream purification and reducing the amount of catalyst for the desired conversion level are the other remarkable features of these technologies.

The objective of this work is to demonstrate the integration of membrane separation with RWGS for CO2 conversion to syngas. The applicability of various (alternative to the conventional process) novel and efficient reactor configurations that include co- or counter-current membrane reactors in sequence is investigated. Innovative designs for the proposed processes are determined based on comprehensive multi-scale modeling and design. A comprehensive, multi-scale, multiphase, steady-state/dynamic, computational fluid dynamics (CFD)-based process model is developed that quantifies the many underlying complex physicochemical phenomena occurring at the pellet and reactor scales.