This paper presents applicability of photocatalytic decomposition of methyl mercaptan using TiO2. A quartz reactor was used in order to elucidate reaction pathway in photocatalytic decomposition of methyl mercaptan. Experimental results showed that more than 99.9% of methyl mercaptan was decomposed within 30 minutes. It was found that the photocatalytic decomposition of methyl mercaptan followed pseudo first order and its reaction coefficient was 0.05min-1 During 30 minutes in the photocatalytic reaction, the concentration of methyl mercaptan, dimethyl disulfide, SO2, H2SO4, COS, H2S were determined. These results showed that 64% of methyl mercaptan were compensated for the increase in sulfur after 30 minutes through the mineralization. The proposed main photocatalytic decomposition pathway of methyl mercaptan was methyl mercaptan→dimethyl disulfide→SO2→H2SO4.

The photocatalytic decomposition characteristics of toluene, acetone, and methyl mercaptan (MM) by UV reactor installed with TiO2-coated perforated plane were studied. The removal efficiency of single toluene, acetone, and MM vapor was increased with increasing oxygen concentration, but decreased with increasing inlet concentration. Elimination capacity of single toluene, acetone, and MM vapor was obtained to be 628 g/m3․day, 1,041 g/m3․day, and 2,158 g/m3․day, respectively. Also, the photocatalytic decomposition of binary vapor consisted of toluene and acetone, toluene and MM, acetone and MM were observed. Elimination capacity of toluene mixed with acetone, toluene mixed with MM, acetone mixed with toluene, acetone mixed with MM, MM mixed with toluene, and MM mixed with acetone was 327 g/m3․day, 512 g/m3․day, 128 g/m3․ day, 266 g/m3․day, 785 g/m3․day and 883 g/m3․day, respectively. The inhibitory effect of acetone was higher than MM in photocatalytic decomposition of toluene, the inhibitory effect of toluene was higher than MM photocatalytic decomposition of acetone, and the inhibitory effect of toluene was higher than acetone in photocatalytic decomposition of MM.

In this study, the photocatalytic decomposition characteristics of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed methyl mercaptan (MM) by UV reactor installed with TiO2-coated perforated plate were studied. The photocatalytic decomposition rate of single toluene, toluene mixed with benzene, toluene mixed with acetone, and toluene mixed with MM fitted well on Langmuir-Hinshelwood (L-H) kinetics equation. The maximum elimination capacity was obtained to be 628 g/m3·d for single toluene, 499 g/m3·d for toluene mixed with benzene, 318 g/m3·d for toluene mixed with acetone, and 513 g/m3·d for toluene mixed with MM, respectively. The negative effect in photocatalytic decomposition of toluene are found to be in the order of acetone>benzene>MM.

The kinetics of the reaction of methyl mercaptan into aqueous diethanolamine were studied over a range in temperature (20～60℃) and amine concentrations (0-40 wt %) using a wetted-sphere absorber. The physicochemical properties needed to interpret the data are the solubility and diffusivity of methyl mercaptan in the aqueous diethanolamine solution. The density and the viscosity were obtained and correlated in the experimental range. The Wilke-Chang equation was applied to estimate the diffusion coefficient. The enhancement factor was found to be high temperature is below than low temperature. It means the absorption rate with chemical reaction is lower than the physical absorption rate.