You are here:
VAPOR PHASE OXIDATION OF DIMETHYL SULFIDE WITH OZONE OVER V2O5/TIO2 CATALYST
SAHLE-DEMESSIE, E. AND V. G. DEVULAPPELI. VAPOR PHASE OXIDATION OF DIMETHYL SULFIDE WITH OZONE OVER V2O5/TIO2 CATALYST. APPLIED CATALYSIS B: ENVIRONMENTAL. Elsevier Science Ltd, New York, NY, 84(3-4):408-419, (2008).
Removal of volatile and odorous compounds emissions from the pulp and paper industry usually creates secondary pollution for scrubbing and adsorption processes or sulfur poising for catalytic incineration. Product studies performed in a flow reactor packed with 10 % V2O5/TiO2 catalyst showed complete conversion of dimethyl sulfide (DMS) in the presence of ozone. The molar yield of CO2 and SO2 was 80 to 90 % with small amounts of partial oxidation products such as and dimethyl sulfone (DMSO2), dimethyl disulfide (DMDS), and dimethyl sulfoxide (DMSO). The oxidation of DMS under ozone only, ozone plus catalyst, and oxygen plus catalyst suggested that the combined used of O3 with catalyst is essential for complete destruction of DMS to COx and SO2. Box-Behnken design was used to determine which factors have significant effect on conversion and selectivity of products. We concluded that product selectivity is strongly influenced by temperature, gas hourly space velocity (GHSV), and ozone concentrations. The catalysts were characterized using XRD, surface area measurements, and SEM techniques. Time-on-stream studies showed that 2 gm of the catalyst kept at 150 oC, gave 99.9 % conversion of DMS in gas stream having concentration of 500 ppmv and ozone-to-DMS ration of 0.9, flowing at 37,000 h-1 for 6 hours. A plausible reaction mechanism has been proposed for the oxidation of DMS based on reaction product distribution and possible intermediates formed.