Oxidation of methyl mercaptan over an activated carbon in a fixed-bed reactor
- Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada)
- Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering
- Okayama Univ. (Japan). Faculty of Engineering
Methyl mercaptan (CH{sub 3}SH) is used at low concentrations in gas as an odorant. In some situations it may be necessary to remove this odorant so that a catalytic reaction system is not poisoned by the sulfur present in the mercaptan. A gas containing approximately 1,000 ppm of methyl mercaptan was used to test an oxidative reaction system for the purification of gas. Experiments were performed for 3.0 h periods in a fixed-bed reactor containing 0.25--5.0 g of Hydrodarco activated carbon in the temperature and pressure ranges 323--448 K and 122--364 kPa, respectively. The gas hourly space velocity was varied from 938 to 4,000 h{sup {minus}1}, with the O{sub 2}/CH{sub 3}SH ratio varying from 1.1 to 1.33 times the stoichiometric ratio. Dimethyl disulfide was the main product, while CO{sub 2} was produced in small amounts. At temperatures above 373 K, 99.99% conversion of the mercaptan was achieved. It was established that higher conversion of CH{sub 3}SH could be achieved while keeping CO{sub 2} production to a minimum by using an O{sub 2}/CH{sub 3}SH ratio in the feed gas close to 1.10 times the stoichiometric ratio. Catalyst deactivation occurred due to deposition of dimethyl disulfide on the catalyst. A kinetic study of this process was performed, and a rate equation for the conversion of CH{sub 3}SH to (CH{sub 3}){sub 2}S{sub 2} and H{sub 2}O was obtained. Since catalyst deactivation occurred by fouling due to deposition of (CH{sub 3}){sub 2}S{sub 2} on the catalyst, the initial rates were considered to be global rates without deactivation effects. According to the Langmuir-Hinshelwood model, the overall rate equation was derived on the basis of the mechanism where the rate-determining step is a surface reaction. The rate data obtained using granular activated carbon were collected well with the rate equation.
- OSTI ID:
- 564164
- Journal Information:
- Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 11 Vol. 36; ISSN IECRED; ISSN 0888-5885
- Country of Publication:
- United States
- Language:
- English
Similar Records
Interstellar methyl mercaptan
High temperature oxidation of methyl mercaptan (shock waves)