Study On The Removal Of Methyl Mercaptan And Dimethyl Sulfide From Carbon Dioxide Stream By Catalytic Oxidation Method

High purity CO2product has been widely used in many fields such as the industry and the social life. The natural CO2gas fields (storages), biological ferm entation gas and the other feed gas set out an unpleasant odor for containing sulfides such as methyl mercaptan and dimethyl sulfide, furthermore result in serious effects on human health and the environment. If these sulfides can not be separated and removed from CO2stream, otherwise these sulfides would worsen the CO2product quality. So, the separation and purification of CO2from a high concentration CO2stream to a higher purity CO2would show an important significance. In this present work, in the removal of CH3SH and CH3SCH3in the CO2stream, TS-1and H2O2were choosed as catalyst and oxidant, respectively. And the methods about dealing with the simulating waste water containing methysulfonic acid and dimethyl sulfone were investigated for the sake of developing a new technology to produce a higher purity or even the food-grade CO2.The main works were listed below:1. The efficiency of TS-1/H2O2system on the removal of CH3SH:The efficiency of TS-1/H2O2system on removal of CH3SH was investigated under various reaction conditions such as CH3SH concentration, H2O2concentration, TS-1dosage, reaction temperature, the height-diameter ratio and the regeneration of TS-1, etc. The results proved that TS-1/H2O2system showed a good removal efficiency on CH3SH, and removing CH3SH in term of φ(CH3SH)=100×106and φ(CH3SH)=100×10-6to φ(CH3SH)<5×10-9from CO2stream, meanwhile CH3SH was oxidated to CH3SO3H and the other substances; TS-1/H2O2system could remove CH3SH to φ(CH3SH)<5×10-9under the condations of c(H2O2)≥1.243×10-3mol/L, catalyst dosage0.5g, reaction temperature30℃, height to diameter ratio≥6; TS-1shows a good performance on the removal of CH3SH even regeneration for5times.2. The efficiency of TS-1/H2O2system on the removal of CH3SCH3:The TS-1/H2O2system shows well performance on the oxidation removal of CH3SCH3by investigating the CH3SCH3concentration, H2O2concentration, TS-1dosage, reaction temperature, the height-diameter ratio and regeneration, ect. Meanwhile CH3SCH3was oxidized to CH3SO2CH3and the other substances. The removal effeciency of CH3SCH3can reach φ(CH3SCH3)<5×10-9under the condations of c(H2O2)≥1.243×10-3mol/L, catalyst dosage0.05g, reaction temperature30℃and height to diameter ratio≥5. The performance of TS-1showed no obvious decrease on the removal of CH3SCH3after5times regeneration.3. Treatment of CH3SO3H and CH3SO2CH3in the simulating waste water by Fenton method:we obtained the appropriate treatment condations to CH3SO3H by investigating the H2O2dosage, the FeSO4dosage, pH and reaction time, and the results exhibites in term of H2O2dosage1.243×10-2mol/L, FeSO4dosage1.5×10-2mol/L, PH2～4, reaction temperature30℃, reaction time2h, CH3SO3H oxidative degradation rate can reach80%under these conditions, and the CH3SO2CH3oxidative degradation rate can reach90%.