Study On Preparation Modification Of Molecular Sieve And Adsorption Separation Of Carbonyl Sulfur From Blast Furnace Gas

With the increasing need for atmospheric environmental protection,the requirements for sulfur content in blast furnace gas（BFG）have become more stringent,with a particular emphasis on the removal of carbonyl sulfide（COS）from BFG.Adsorption technology,with its simple process and diverse adsorbents,has shown excellent performance in desulfurization.However,traditional adsorbents have limitations in the removal of COS,making modified adsorbents essential to improve COS desulfurization.This thesis primarily focuses on the modification of 13X and ZSM-5molecular sieves and examines the adsorption performance of the prepared adsorbents for COS.The main research content includes the analysis of modifications and the evaluation of their impact on COS adsorption.（1）The study focused on the modification of 13X molecular sieves using the equal volume impregnation method with the inorganic base Na OH to improve its adsorption and desulfurization performance.By controlling the concentration of Na OH and the impregnation temperature,a series of adsorbents were prepared and evaluated.Results revealed that the 13X-M adsorbent had a saturation adsorption time of 355.34 min and a saturation sulfur capacity of 17.69 mg COS/g at an adsorption temperature of 80℃.（2）Based on the previous research,the 13X-M adsorbent was treated with an organic amine solution（Ethane diamine:Ethanol）to regulate its sulfur removal performance by controlling the volume ratio of the organic amine solution.The results indicated that organic amine modification did not affect the structure of the 13X molecular sieve,but it did decrease the crystallinity of the adsorbent,resulting in a roughened surface and reduced specific surface area.However,the modified adsorbent 13X-D showed a significantly enhanced surface alkalinity,and N-S bonds were formed between 13X-D and COS,leading to the production of corresponding sulfates or H₂SO₄.（3）In addition,the study investigates the desulfurization performance of metal-modified ZSM-5 molecular sieve and evaluates the effect of adsorption temperature,silica-to-alumina ratio,metal species,and metal loading on its performance.The results show that ZSM-5-Zr（3）adsorbent exhibited the best desulfurization performance at an adsorption temperature of 20℃and a silica-to-alumina ratio of 40.The modified adsorbent did not affect the structure of the molecular sieve but reduced the pore size of the adsorbent,and metal Zr increased the surface alkalinity of the adsorbent.Combined with FT-IR characterization,it was found that the absorption peak of-C-S-bond appeared at 623 cm^-1 of ZSM-5-Zr（3）samples after the reaction,indicating that the corresponding metal sulfide was produced after the reaction.