Cyclic effects of sulfur deposition on CO2 by vacuum pressure swing adsorption from blast furnace gas

• Sulfur deposition only occurs with coexisting H₂S and O₂, reaching a maximum of 13.21%. • Su accumulates as S and SO 4 2- , reducing 82.26% surface area of the adsorbent. • Sulfur deposition diffuses upwards in the mass transfer zone, with a density of ∼0.34 g/cm³. • Cyclic sulfur effect has been evaluated with significantly impact on CO₂ adsorption. • Critical insights for designing sustainable CO₂ capture technologies have been provided. Vacuum pressure swing adsorption has a high potential to reduce CO 2 from blast furnace gas, while there are also H 2 S and COS exist in the blast furnace gas, and the sulfur deposition effect on CO 2 adsorption over zeolite was quite necessary to be studied. In this work, laboratory fixed bed evaluation and two-tower pressure swing adsorption apparatus were employed and it has been found that sulfur deposition occurs only in the presence of coexisting H 2 S and O 2 without water and the highest sulfur accumulation is 13.21% for the adsorbent under CO 2 +H 2 S+COS+O 2 atmosphere. Cyclic evaluation of H 2 S and COS on CO 2 cyclic adsorption was first investigated, and the sulfur is ultimately converted into S monomers and sulfate, which can be deposited in the pore channel, with the specific surface area reduced 82.26% of the adsorbent. Furthermore, sulfur deposition gradually diffused with the upward shift of the adsorption mass transfer zone, and the sulfur deposition densities are calculated to be approximately 0.34 g/cm 3 . These mechanisms and data demonstrate the significant impact of sulfur deposition on sustainable CO₂ capture in industrial processes, and provide important guidance for the design of CO₂ capture technologies, which is of great importance for carbon reduction.