High Temperature Reaction Kinetics of Boron Oxides
Abstract
Experiments using laser photolysis of water vapor to probe H +OH recombination chemistry in a mixture of combustion products of hydrogen, oxygen and phosphine are reported. When combustion products of phosphine are present, a large increase in the apparent H +OH recombination rate is observed. Progress was made in determining a baseline reaction model which describes the observed reaction rate. The thermochemical properties of 17 simple phosphorus species (possible combustion products of phosphine and oxygen) were assembled and the equilibrium densities of the phosphorus species were calculated under typical test conditions. The thermochemical properties of many of the phosphorus species have not been previously determined and were estimated from the results of ab initio quantum chemical calculations available in the literature. The six phosphorus species with the largest densities were used in the construction of a reaction model. Rate constant values were estimated using standard methods for the metathesis reactions and using simplified RRKM calculations to estimate the rates of recombination reactions. The increase in the observed rate of OH recovery was well described by this reaction set at the experimental conditions of 1970 K and 532 Torr. Two phosphorus containing recombination reactions appear to be rate limiting for H+OH recombination. Reaction rates, Phosphine, Phosphorus oxide, Recombination, Kinetics, Photolysis, Thermochemical, Rate constant.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1992
- Accession Number
- ADA257402
Entities
People
- Allen Twarowski