Rate coefficients of combustion/fuel conversion reactions by high-temperature photochemistry. Progress report, September 1, 1979-August 31, 1980. [400 to 1700 K and 1200 to 2600 K

Abstract

Reliable kinetic data on isolated elementary combustion reactions spanning a broad temperature range are required for modeling and scaling studies aimed at improving the performance of, and reducing the pollutant formation from, fossil-fuel burning devices. Such data are generally not available. In the present work a new technique, High Temperature Photochemistry (HTP), has been developed to provide such data. It combines the technology of the high-temperature, fast-flow reactors (HTFFR) we developed to study kinetics of metal atom/oxide reactions in the 300 to 1900 K range with the methodology of the flash photolysis technique which, although used widely for study of such combustion reactions, has previously been limited to studies at or near room temperature. This report discusses aspects of the complete HTP study on the benchmark reaction, O + CH/sub 4/ ..-->../sup (1)/ OH + CH/sub 3/, including new data in the 1500 to 1700 K range obtained in the present contract year. The data which extend from 400 to 1700 K overlap the previous low temperature (250 to 950 K) and high temperature (1200 to 2600 K) measurements of k/sub 1/(T) and show a curved Arrhenius plot, in excellent agreement with the more reliable work of others and with recent theoretical work. The HTP data can be fit by an empirical rate coefficient expression which is given. The HTP apparatus has been modified to conduct measurements on the reaction OH + C/sub 6/H/sub 6/ and these experiments have been initiated.