阻挡放电联合金属氧化物催化降解H2S的研究

采用介质阻挡放电联合金属氧化物催化降解气态H2S,考察了单组分及复合金属氧化物催化剂、催化剂与低温等离子体结合方式对H2S及副产物O3去除性能的影响,分析了等离子体联合Mn复合金属氧化物催化降解H2S机理。结果表明,金属负载量相同条件下,电压低于22kV时,Mn复合金属氧化物对H2S的催化活性高于单组分Mn金属氧化物,催化活性及对O3的分解能力从大到小依次为:Ag+Mn、Cu+Mn、Fe+Mn、Mn。当电压为18 kV时,Ag+Mn、Cu+Mn、Fe+Mn复合催化剂分别比单组分Mn催化剂对H2S的去除效率提高了近10%、6%、4%。等离子体后催化区域中Mn催化剂催化氧化H2S的效率明显低于等离子体催化区域。Mn催化剂在等离子体后催化区域中能有效催化分解O3。随着电压的升高,Mn金属氧化物在等离子体后催化区域对H2S催化作用逐渐增强。在电压22 kV时,等离子体联合后催化比单独等离子体作用时,H2S去除效率提高了近11%。

On the decomposition of hydrogen sulfide by means of dielectric barrier discharge and metal oxide catalysis

The paper takes as its research focus the study of the decomposition of hydrogen sulfide by means of dielectric barrier discharge and metal oxide catalysis.In order to promote our intended study,we have done experiments with the dielectric barrier discharge(DBD) plasma combined with metal oxide catalysis to remove the gaseous H2S.We have also investigated the effects of metal oxide catalyst type,i.e.single-component and complex-component,along with the relation between the catalyst and non-thermal plasma(NTP) on the simultaneous removal of H2S and O3.It is on the basis of the work done above,we have brought about a model for proper interpretation of the catalytic decomposition mechanism of H2S.The experimental results we have gained show that under the condition of the same active component loading and at the same voltage applied in the NTP reactor,the catalytic activities of the Mn-complex catalyst prove to be higher than that of the single-component catalyst at the voltage applied below 22 kV.In terms of H2S removal efficiency,the metal oxide catalysts are expected to be ranked as follows: Ag+Mn>Cu+Mn>Fe+Mn>Mn,which is also in accord with the sequence of O3 decomposition ability.At 18 kV,compared to Mn catalyst(single-component),H2S removal efficiency with Ag-Mn catalyst,Cu-Mn catalyst and Fe-Mn catalyst prove to be increased by 10%,6% and 4% respectively,whereas at the voltage of 18 kV,the removing efficiency of the Ag-Mn catalyst can be expected to reach 92%.The highest H2S removal efficiency we have achieved through experiments by using Mn-complex catalysts.The catalysts placed in the downstream of NTP also display a high catalytic activity for H2S.As to the H2S removal efficiency,Mn-catalyst in the post plasma zone turned to be lower than that in plasma area.But Mn-catalyst in the post-plasma zone tends to be able to decompose O3 effectively both in air and H2S feeding environment. In the case of H2S feeding,ozone concentration in the post-plasma area can be made to reach the maximum value at 18 kV,then showing a downward tendency with the increase of the voltage applied.Therefore,with the increase of the voltage applied to the NTP reactor,Mn-catalyst in the post-plasma zone tends to gradually increase in the catalytic ability of H2S.And at the voltage applied of 22 kV,H2S removing efficiency is expected to improve by 11% with the help of NTP combined with post-plasma catalyst than the application of NTP alone.