High-Efficient Calcium-Based Adsorbent for Dry Desulfurization

Developing high activity calcium-based adsorbent is still one of the difficult problems for calcium-based adsorbents for dry desulfurization. Herein, we develop the surfactant induction coprecipitation strategy to construct high active layered mesoporous calcium hydroxide. It was found that ethanol as a solvent could modify the lamellar morphology of calcium-based adsorbent, that the surfactant (CTAB) plays an important role in regulating the pore structure to obviously improve the desulfurization activity and utilization efficiency, and that its breakthrough sulfur capacity reaches 371.7 mg g−1 at 350 °C. The excellent desulfurization performance is attributed to the unique 2D lamellar morphology, high specific surface area, and mesopore structure of calcium hydroxide. Experimental and theoretical results reveal that SO2 is preferentially adsorbed on the surface of Ca(OH)2, and reacts with Ca(OH)2 to form CaSO3. CaSO3 is then oxidized by O2 in the presence of SO2 and CO2 to form CaSO4, and the presence of CO2 inhibited the catalytic oxidation of sulfite to sulfate by O2 from air. This synthesis strategy offers a facile method to construct efficient 2D adsorbent for SO2 removal.