Improvements in the Pre-Combustion Carbon Dioxide Sorption Capacity of a Magnesium Oxide–Cesium Carbonate Sorbent

Abstract

Cesium-carbonate-doped magnesium oxide has been shown to be a prospective candidate for pre-combustion CO2 capture at temperatures between 300 and 410 °C. Materials were synthesized by wet mixing commercially available materials as well as a solvothermal approach using a magnesium methoxide in methanol solution. The materials were activated by heat treatment at 600–610 °C to yield the active CO2 sorbent. The sorbents showed working capacities of around 4 wt % in up to 25 partial pressure swing (12 min of sorption and 24 min of desorption) cycles. If the cesium carbonate was dissolved in the magnesium methoxide solution before solvothermal synthesis, multi-cyclic working capacities were increased to 5 wt %. Brunauer–Emmett–Teller surface area measurements of the activated materials showed that the solvothermal method led to materials with higher surface areas of ∼13 m2/g, as compared to 3.4 m2/g if made from commercial MgO. Transmission electron microscopy showed the morphology of the activated solvotherma...