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Study On Simultaneous Dry Removal Of Hydrogen Sulfide And Phosphine By Loaded Mesoporous Alumina

Posted on:2018-02-04Degree:MasterType:Thesis
Country:ChinaCandidate:Y W WangFull Text:PDF
GTID:2321330518961332Subject:Environmental engineering
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There are a lot of yellow phosphorus production enterprises in Yunnan Province,and a large amount of yellow phosphorus tail gas is produced in the production process.And a great deal of CO gas(85%?95%)contained in the yellow phosphorus tail gas is an important raw material gas for the C1 chemistry.But the yellow phosphorus tail gas cannot be directly use to Cl chemistry because it contains some impurity gases which can affect production via causing the relevant catalysts poisoned and lose activity,such as H2S(800?1100mg/m3),PH3(750?1200mg/m3),HCN(100?350mg/m3),COS(700?1000mg/m3).Therefore,in order to realize the resource utilization of yellow phosphorus tail gas,it is a key step to remove the impurity gas from yellow phosphorus tail gas.At present,there is no systematic and in-depth study on the simultaneous removal of H2S and PH3 in yellow phosphorus tail gas.In view of the above problems,according to the characteristics of yellow phosphorus tail gas,the mesoporous alumina with selective adsorption capacity was selected as the carrier material.The purpose of simultaneous purification of H2S and PH3 in yellow phosphorus tail gas by loading active component on the carrier was achieved in this research.This paper mainly includes two aspects:preparation and activity evaluation of supported mesoporous alumina materials;characterization of supported mesoporous alumina materials and analysis of reaction mechanism.In this research,mesoporous alumina was used as carrier,and evaporation induced self-assembly method was used to prepare materials.The performance of simultaneous removal of H2S and PH3 with MP-Al2O3 and SS-Al2O3,the types and contents of the first active component,the contents of the second active component were investigated.The activity of materials was evaluated by conversion of H2S and PH3,sulfur and phosphorus capacity.At the same time,the physical and chemical properties of materials and relevant reaction mechanism were analysed via many characterization technologies(BET,XRD,SEM,FE-SEM,TEM,H2-TPR,XPS,in suit IR).According to the results of activity evaluation,the performance of MP-Al2O3 was better than SS-Al2O3;the material showed the best performance of simultaneous removal of H2S and PH3 when the content of first active component Cu was 60%(12mmol),and the 100%conversion of H2S and PH3 was 230min and 135min respectively,and the sulfur and phosphorus capacity were 6.70mol H2S/g and 6.53mol PH3/g;the material showed the best performance of simultaneous removal of H2S and PH3 when the content of CeO was 0.6%(0.12mmol),and the 100%conversion of H2S and PH3 was 435min and 345min respectively,the sulfur and phosphorus capacity were individuly 9.12mol H2S/g and 8.09mol PH3/g.According to the analytical results of BET,SEM/TEM and XRD,the supported mesoporous alumina is mesoporous materials.Among them,the specific surface area and total pore volume of mesoporous alumina are the largest.The physical properties,such as the specific surface area of the materials will be decreased with the increase of the Cu contents.Combining the relevant results of activity evaluation,it is clear that the prepared materials mainly depended on the active components to remove the H2S and PH3.In addition,a small amount of CeO2 is able to modify the CuO grains.Meanwhile,this function can improve the specific surface area of the materials,but it is not the main reason for improving the materials perfonnance.The reduction temperature of CuO will be reduced due to the exist of CeO2.This phenomenon shows that there is an interaction between the two active components.A widely accepted explanation to interpret that phenomenon is that the copper ion can penetrate to lattice of ceria,with increasing the oxygen storage capacity of ceria.Thus,the activity of materials was enhanced.And the relevant reaction mechanism was speculated according to the analytical results of XPS and in suit IR:on the mesoporous alumina material,only P2O5 was formed via the oxidation reaction between PH3 and O2.After loading the active component CuO,H2S reacted with CuO to produce CuS and H2O,while P2O5 and H2O reacted further to form(PO3)33-.After loading the active component of two CeO2,(PO3)33-will further to form PO43-.
Keywords/Search Tags:mesoporous alumina, CuO, CeO2, H2S and PH3, simultaneous adsorption-oxidation
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