Preparation Of Co-NH₂-SBA-15 And The Study On Its Performance Of Desulphurization

Hydrogen sulfide is one of the most important pollutants in the atmosphere,which is widely used in coke oven gas,natural gas and other industrial gases.It is a poisonous gas with an extremely low olfactory threshold,not only harmful to industrial production,but also affects human health.The demand for hydrogen sulfide removal in China increased,more and more desulfurizers and desulfurization methods appeared recently.Ordered mesoporous materials is widely used in separation,adsorption and catalysis which has uniform pore size,large specific surface area and highly ordered channel.Ordered mesoporous materials are conveniently for functional modification.In this paper,the mesoporous molecular sieve SBA-15 was prepared by hydrothermal synthesis.The APTS and cobalt acetate were used to modify SBA-15,NH₂-SBA-15 and Co-SBA-15.The zeolite molecular sieves were characterized by SEM,XRD,FT-IR,XPS,TG-DTA and BET.The influence of temperature and gas flow rate on desulfurization performance of the modified adsorbent were investigated.The experimental results are showed as below:（1）Under the conditions as below:the amino and silicon molar ratio is 0.20,the volume fraction of hydrogen sulfide is 227μL/L,the temperature is 40℃,the gas flow rate is75ml/min;the penetration sulfur capacity and saturated sulfur capacity of NH₂-SBA-15 come to 0.151mmol/g and 0.190mmol/g;When the Co loading mass fraction is 8%,the volume fraction of hydrogen sulfide is 227μL/L,temperature is 50℃,gas flow rate is 75ml/min,the penetration sulfur capacity and saturated sulfur capacity of NH₂-SBA-15 come to 0.103mmol/g and 0.128 mmol/g.（2）APTS was used as the amino silane coupling agent to graft-NH₂ into the SBA-15 skeleton,The H₂S composite mesoporous material was prepared by the method of combining maceration and grafting.As a result,-NH₂ entered the skeleton of SBA-15,and Co was attached to the surface of SBA-15 in the form of Co₃O₄.Evaluation performance results showed that,when amino and silicon molar ratio was 0.20,Co loading mass fraction was 8%,the volume fraction of hydrogen sulfide was 227μL/L,the temperature was 25℃,gas flow rate was 75 ml/min,the penetration sulfur capacity and saturated sulfur capacity of Co-NH₂-SBA-15 come to 0.151 mmol/g and 0.190 mmol/g.Therefore,the grafting of-NH₂and the loading of Co determined the desulfurization performance of the adsorbent.（3）NH₂-SBA-15,Co-SBA-15 and Co-NH₂-SBA-15 adsorbent can be regeneraed under mild conditions.Regeneration experimental results show that the regeneration times of8%Co-0.20NH₂-SBA-15 can be up to 15.The kinetics and thermodynamics of adsorption process were investigated.The stability of molecular sieves was improved by the addition of-NH₂,the strength of the skeleton was increased by the addition of Co.The modified method:loading metal and grafting organic groups increased the adsorption capacity of SBA-15.The service life of SBA-15 was extended,and the application value increased.