Propyne Pyrolysis in a Flow Reactor: An Experimental, RRKM, and Detailed Kinetic Modeling Study

The pressure-dependent rate coefficients for several reactions relevant to propyne pyrolysis were determined with ab initio quantum mechanical calculations and Rice−Ramsperger−Kassel−Marcus (RRKM) analyses. These reactions include the mutual isomerization of propyne and allene, the chemically activated reactions of propyne and allene with the H atom and of acetylene with methyl on the C 3 H 5 potential energy surface. Propyne pyrolysis was experimentally studied in a flow reactor at 1210 K and 1 atm. A detailed reaction mechanism, employing the current RRKM rate coefficients, is shown to accurately predict the experimental acetylene and methane profiles determined in the flow reactor and literature shock-tube data of propyne and allene pyrolysis up to 1500 K.