TY - JOUR
T1 - Toluene destruction in the Claus process by sulfur dioxide: A reaction kinetics study
AU - Sinha, Sourab
AU - Raj, Abhijeet Dhayal
AU - Alshoaibi, Ahmed S.
AU - Alhassan, Saeed M.
AU - Chung, Suk Ho
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work has been financially supported by the Gas Processing and Materials Science Research Centre, The Petroleum Institute, UAE.
PY - 2014/10/7
Y1 - 2014/10/7
N2 - The presence of aromatics such as benzene, toluene, and xylene (BTX) as contaminants in the H2S gas stream entering Claus sulfur recovery units has a detrimental effect on catalytic reactors, where BTX forms soot particles and clogs and deactivates the catalysts. BTX oxidation, before they enter catalyst beds, can solve this problem. A theoretical investigation is presented on toluene oxidation by SO2. Density functional theory is used to study toluene radical (benzyl, o-methylphenyl, m-methylphenyl, and p-methylphenyl)-SO2 interactions. The mechanism begins with SO2 addition on the radical through one of the O atoms rather than the S atom. This exothermic reaction involves energy barriers of 4.8-6.1 kJ/mol for different toluene radicals. Thereafter, O-S bond scission takes place to release SO. The reaction rate constants are evaluated to facilitate process simulations. Among four toluene radicals, the resonantly stabilized benzyl radical exhibited lowest SO2 addition rate. A remarkable similarity between toluene oxidation by O2 and by SO2 is observed.
AB - The presence of aromatics such as benzene, toluene, and xylene (BTX) as contaminants in the H2S gas stream entering Claus sulfur recovery units has a detrimental effect on catalytic reactors, where BTX forms soot particles and clogs and deactivates the catalysts. BTX oxidation, before they enter catalyst beds, can solve this problem. A theoretical investigation is presented on toluene oxidation by SO2. Density functional theory is used to study toluene radical (benzyl, o-methylphenyl, m-methylphenyl, and p-methylphenyl)-SO2 interactions. The mechanism begins with SO2 addition on the radical through one of the O atoms rather than the S atom. This exothermic reaction involves energy barriers of 4.8-6.1 kJ/mol for different toluene radicals. Thereafter, O-S bond scission takes place to release SO. The reaction rate constants are evaluated to facilitate process simulations. Among four toluene radicals, the resonantly stabilized benzyl radical exhibited lowest SO2 addition rate. A remarkable similarity between toluene oxidation by O2 and by SO2 is observed.
UR - http://hdl.handle.net/10754/563804
UR - https://pubs.acs.org/doi/10.1021/ie502617r
UR - http://www.scopus.com/inward/record.url?scp=84908154630&partnerID=8YFLogxK
U2 - 10.1021/ie502617r
DO - 10.1021/ie502617r
M3 - Article
SN - 0888-5885
VL - 53
SP - 16293
EP - 16308
JO - Industrial & Engineering Chemistry Research
JF - Industrial & Engineering Chemistry Research
IS - 42
ER -