(186a) Integration of CO2 Capture and Storage with the Water-Gas Shift Reaction in a High Pressure Aqueous System for Sustainable Energy Conversion

By integrating mineral carbonation with various energy conversion systems, greater sustainability can be achieved in the use of carboneous fuels. The hydrogen yield of the water-gas shift reaction can be enhanced by carbonation reactions, as the removal of CO₂ from the gas phase results in a swing of the water gas shift equilibrium towards the products. Furthermore, steam, which is already present as a reactant in the water-gas shift, serves to promote carbonation reactions. This study investigates the integration of carbonation and water gas shift reactions under favorable conditions for Mg(OH)₂ carbonation (slurry phase, 200 ºC) in a high pressure batch reactor. Preliminary results confirm the enhanced yield of hydrogen in the presence of the Mg(OH)₂ slurry. The presence of a bulk aqueous phase in the water gas shift system does pose some challenges, namely the existence of competing side reactions which are under continued investigation. For example, CO(g) reacts with hydroxide in solution to create aqueous formate ions which can either decompose further to yield hydrogen or remain in solution, depending on the aqueous conditions. Comprehensive solid analyses via TGA, XRD, and SEM allow for qualitative and quantitative compositional characterization of reacted solids and micro GC provides gas phase analysis.