Activated Carbon Based Carbon Sulfide Hydrolysis Catalyst Selection And Dynamics Research

The off-gas of yellow phosphorus containing a large portion of CO, produced in the process of yellow phosphorus, is a high quality material gas for C1(one carbon) chemical industry. CS2is a harmful gas which can pollute the environment and affect the catalysts in C1chemical industry. If yellow phosphorus tail gas can be used as raw material gas to synthesize chemical product, it’s necessary to remove CS2. According to the characters of yellow phosphrus tail gas, the CS2and product of H2S can be removed simultaneously by catalytic hydrolysis.In this work a series of coal-based active carbon (AC) catalysts, combined with metal oxides, were prepared by sol-gel method for carbon disulfide (CS2) hydrolysis and their performances for CS2hydrolysis were investigated. The influences of preparing the conditions for catalytic activities were studied, namely, the methods of catalyst preparation, the kinds and amount of metal oxide, the calcination temperature, plus the types and content of alkalis. The influences of operation conditions such as:temperature, O2concentration, space velocity, CS2inlet concentration and relative humidity (RH) were also discussed respectively. The reactivation of Fe-Cu-Ni/AC catalyst for hydrolysis of CS2was also studied.The experiment results were as follows:(1) The optimum preparation conditions for the catalyst occurred with the addition of5%ferric oxide (Fe2O3), Fe:Cu:Ni (mole ratio)10:2:1,5%KOH and calcination temperature at400℃.(2) The suitable operation conditions were such as:reaction temperature (50℃),2.3%O2concentration,5%relative humidity and CO atmosphere. The results also showed that CS2hydrolysis reaction is sensitive to the reaction temperature and relative humidity was analyzed by experiments.(3) The experimental results showed that the catalyst with KOH solution wash reactivation exhibited the best catalytic activity. Moreover, the catalytic capacity increased significantly compared with the fresh sample. (4) The reaction kinetics of catalytic hydrolysis of CS2over Fe-Cu-Ni/AC catalyst was fitted by MATLABR2009a surface fitting tool kit version and expressed as follows:(5) Based on the XPS、FT-IR and XRD result, some literatures and calculation, the reaction mechanism of CS2hydrolysis over Fe-Cu-Ni/AC catalyst was proposed. There were two steps on the surface of catalyst in the reaction process:hydrolysis of CS2process and oxidation of H2S from the hydrolysis. The rate of CS2adsoption was the control step of CS2hydrolysis. The adsorptive CS2was continuously hydrolysised to H2S on the active center with the reaction and the H2S was oxidized to elemental sulfur and sulfate on the oxidation center finally.