(32) performed thiophene thermolysis (1598–2022 K) in a shock tube. In addition to methane, benzene, and hydrogen sulfide, a large number of secondary condensation products were identified as the pyrolysis products of thiophene. (31) studied thiophene pyrolysis using a quartz continuous flow reactor. Later, Cullis and Norris (30) performed thiophene pyrolysis under carbon formation conditions and commented that hydrogen sulfide was one of the major products. In 1959, Wynberg and Bantjes (29) studied thiophene cracking in a continuous flow reactor and identified dithiophenes, carbon disulfide, free carbon, hydrogen sulfide, and hydrocarbons in the pyrolysis products. Possible secondary reactions in the products have also been discussed.Īs the simplest thiophene sulfur, thiophene (C 4H 4S) is worthy of a detailed investigation as it could be a representative for all thiophenes. By contrast, atomic sulfur and H 2S are difficult to be directly produced. Significant amounts of the thioformyl (HCS) radical and CS could also be yielded. Thioketene (SC 2H 2) and ethyne (C 2H 2) are the major pyrolysis products at all temperatures. The unimolecular pyrolysis of thiophene is mainly initiated by the ring-H migrations, whereas the C–S bond rupture has limited contribution to the overall pyrolysis rate. The Arrhenius expression for thiophene unimolecular pyrolysis has been redetermined as k = 1.21 × 10 13 × exp. By comparison with preceding experimental results, the kinetic model shows good performance in calculating the thiophene pyrolysis rate.
Rate coefficients of the elementary reactions are computed using variational transition-state theory at the CCSD(T)/CBS level to develop a kinetic model. High-level ab initio methods have been employed to deduce the potential energy surface. In this work, we investigate the unimolecular pyrolysis of thiophene from a kinetic perspective.
Removal of thiophenes has profound significance in environmental protection. Thiophenic sulfur is the most stable and abundant organic sulfur species in petroleum.
0 kommentar(er)
