Combustion chemistry of carbon disulphide (CS₂)

The presence of sulphur in fossil fuels contributes uncertainty to predicting their combustion behaviour. Detailed understanding of the combustion chemistry of sulphur species, comprising precise kinetic models, will enable optimisation of important industrial operations, such as Claus process in desulphurisation of hydrocarbons. The present contribution reports new experimental measurements on oxidation of carbon disulphide under dry and wet conditions from experiments performed in a jet-stirred reactor (JSR) and develops a comprehensive oxidation mechanism of CS₂ with updated COS/O₂ subset of reactions, based on addition of intersystem-crossing reaction corridors. We performed the experiments within the temperature range of 650–1100 K, under atmospheric pressure, and equivalence ratios of 0.7, 1.0 and 1.3, for the residence time of 0.3 s. Online infrared spectroscopy identified CO and SO₂ as primary oxidation products, distinguishing COS as the major intermediate species. Within the temperature window of 650–1100 K, the presence of moisture exhibits no obvious effect on the oxidation of CS₂, due to high kinetic stability of H₂O. The modelling predicts the conversion of CO to CO₂ at temperatures in excess of 1200 K. The measured concentration profiles (CS₂, COS, CO and SO₂) facilitated the validation, as well as the improvement of the previously existing mechanism of CS₂ oxidation. Good agreement appears between measured and modelled onset temperatures and consumption profiles for detected species, confirming the robustness of the model.