Study on the reaction mechanism of thiophene aquathermolysis

In this paper, aiming at the phenomenon of hydrogen sulfide (H₂S) formation in heavy oil recovery by steam injection, thiophene was selected as the model compound, then the experiments of pyrolysis and aquathermolysis were carried out in the reaction kettle with high temperature and high pressure in lab. Based on testing the content of gas products and liquid products, the reaction paths and broken bond mechanism of pyrolysis and aquathermolysis of thiophene were discussed. The results show that the main hydrocarbon products are methane and butane during the aquathermolysis of thiophene; besides a large number of unreacted thiophene, liquid products include a little of alkylthiophene, thienyl-thiophene and some derivatives. The protonation, primary hydrolysis and secondary hydrolysis are very important in the formation of H₂S. The cleavage of the C-S bond is an important step in the aquathermolysis and pyrolysis reaction of thiophene.