Unraveling the Ketene Formation under Pyrolysis condition of 1-C4H8+CO2
CO2 is not an inert compound, but it does participate in reactions that reduce the formation of polycyclic aromatic hydrocarbons and soot through a combination of chemical, thermal, and dilution effects. Nevertheless, understanding of the chemical effect of CO2 addition in combustion environments remains incomplete. In this work, the pyrolysis experiment that blended 1-butene (1-C4H8) with CO2 was conducted to explore possible products based on experimental detections. Pure 1-C4H8 pyrolysis was also studied under the same conditions as the contrast experiment. In the experimental process of the mixture pyrolysis, an obvious signal at a mass-to-charge ratio of 42 was observed. Based on the mass spectrum and photoionization efficiency spectrum (except for propene), this species proved to be ketene. In addition to the traditional reaction channels for ketene formation, theoretical computations demonstrated that the reactions of C2H3 and CO2 were likely responsible for ketene formation under pyrolytic conditions in the mixture pyrolysis. Also, related rate coefficients for C2H3 + CO2 were calculated here. Present work can provide valuable kinetic data to improve the understanding of CO2 sub-mechanism. It can also be used as a reliable reference for further investigation of CO2 combustion.
Yitong Zhai is a Ph.D. student supervised by Prof. Mani Sarathy in Clean Combustion Research Center (CCRC). He joined the Chemical Engineering program, PSE division in August 2019. His research is focusing on highly oxygenated molecules formation under atmospheric condition and fuel kinetic models.