A study of benzene formation in a laminar flow reactor

The formation of benzene in a series of fuel-rich premixed reactant systems with a constant carbon-to-oxygen ratio of approximately 0.6 is investigated experimentally in a laminar flow reactor at temperatures between 1073 and 1823 K and at atmospheric pressure. The experimental data are compared to model results using a chemical kinetic mechanism based on the work of Pope and Miller. Modifications to their mechanism include changes in the reaction subsets of C 2 H 2 , C 3 H 4 , and 1,3-C 4 H 6 . The experimental data show that benzene formation may exhibit two distinct peaks as a function of the reaction temperature. A high-temperature peak is observed between 1500 and 1600 K, and it appears with a similar magnitude of concentration for all sets of reactants. A low-temperature peak is observed between 1200 and 1300 K for reactant sets CH 4 /C 2 H 2 , CH 4 /C 3 H 4 , and CH 4 /1,3-C 4 H 6 . The low-temperature peak is comparable in magnitude for the CH 4 /C 2 H 2 and CH 4 /1,3-C 4 H 6 mixtures, while it is 5 times larger in the CH 4 /C 3 H 4 system. In general, there is good agreement between modeling and experimental results. However, some improvements are needed, in particular in the acetylene chemistry and the initiation kinetics for 1,3-butadiene.