Preparation And Performance Of Molecular Sieves Based On Carbonyl Sulfide Adsorption

At present,most of the industrial adsorption of carbonyl sulfide is a one-time consumption adsorbent.Although the adsorption capacity is large and the removal rate is high,it cannot be regenerated after adsorption and becomes industrial waste,causing secondary pollution.In view of the above reasons,this topic synthesized high temperature resistant,acid and alkali resistant molecular sieves by using silicon source and aluminum source to remove carbonyl sulfide（COS）in industrial waste gas.Molecular sieves have large specific surface area and pore volume,and can carry out gas adsorption through a large number of pore cavities.However,industrial waste gas has many components and low COS concentration,so desulfurizers with high adsorption performance are required.Therefore,the molecular sieve is modified to improve the COS adsorption capacity.COS is an acid gas with S element in its molecule,metal ions have good bonding ability to S,and basic groups also have good adsorption ability to acid gas.Therefore,the method of metal ion modification and ionic liquid loading was adopted to improve the adsorption capacity of molecular sieve,and also had better adsorption selectivity for COS adsorption.1.Microporous Na Y molecular sieve and mesoporous SBA-15 molecular sieve carrier were successfully prepared by prolonging the aging time by means of hydrothermal synthesis.2.Using the microporous Na Y molecular sieve as the base,five kinds of metal ions(Zn²⁺,Co²⁺,Ni²⁺,Ce⁴⁺,Cu²⁺)were doped into the molecular sieve framework by ion exchange,and the advantages of different metal ions were discussed.3.Using gas-phase Si O₂ and mesoporous SBA-15 molecular sieves,respectively,the ionic liquid was loaded onto the surface and pores of the carrier by the impregnation method,and the COS adsorption experiment was carried out.Effects of1-ethyl-3-methylimidazolylglycine（[C₂mim][Gly]）,1-butyl-3-methylimidazolylglycine（[C₄mim][Gly]）and 1-Ethylamino-3-methylimidazolium bromide（[Aemim][Br]）ionic liquids and different loading concentrations on the adsorption properties on COS at different adsorption temperatures were discussed.The COS adsorption test experiments show that the synthesized microporous Na Y molecular sieve adsorbent has a better COS adsorption effect than some commercial microporous molecular sieve adsorbents such as Na Y,USY andβ-type.After modification by metal ions,the adsorption effect is significantly improved.Among them,the best one is Cu Y molecular sieve adsorbent,which not only has a better recycling effect than other adsorbents,but also has a better adsorption effect at 200°C than room temperature adsorption.Therefore,the adsorbent has the potential of industrial high temperature COS adsorption.For the supported ionic liquid-type mesoporous molecular sieve adsorbent,the results show that the mesoporous SBA-15molecular sieve supports 9.0 g of[C₂mim][Gly]ionic liquid（SBA-15-C₂9.0 is the maximum loading concentration）adsorbent than gas-phase Si O₂The COS adsorption effect of the[C₂mim][Gly]ionic liquid（Si O₂-C₂4.0 is the maximum negative concentration）adsorbent with a load of 4.0 g is greater and increases exponentially,and its COS penetration adsorption capacity can reach 11.38 mg·g^-1,which has great application potential in the field of COS adsorption.The COS adsorption effect was enhanced by using metal modification on the microporous molecular sieve,and the effects of adsorption temperature and cyclic regeneration on the performance of the adsorbent were discussed.For the gas-phase Si O₂ and SBA-15 mesoporous molecular sieve supports,by loading[C₂mim][Gly]on the surface and pores,it can be combined with acid-base COS,thereby enhancing the adsorption effect and adsorption selectivity.The research results have certain guiding significance for the basic research and industrial application of new carbonyl sulfide adsorbents.