Development of a Method to Determine The Autoxidation of Turbine Fuels.
Abstract
The report describes the development of a research grade test method that allows the precise evaluation of antioxidants and prediction of the rate of peroxide formation at ambient conditions from data obtained from accelerated oxidation experiments at elevated temperatures. The rates of peroxide formation in 10 model jet fuels were measured at several temperatures ranging from 43' to 120 deg c, with oxygen partial pressures ranging from approximately 10 to 1140 kPa. Results of rigorously controlled experiments agreed with a kinetic model of the autoxidation process, which showed that the peroxide concentration increased as the square of stress duration. Within the experimental limits, the rate of peroxide formation did not depend on the oxygen partial pressure. Arrhenius correlations of global rate constants determined from peroxide concentration time histories in accordance with the kinetic model showed that a single autoxidation was accountable for the results obtained in the 430 to 120 deg C temperature range. This method has also been used to evaluate the effectiveness of several hindered phenolic antioxidants to inhibit the formation of peroxides in two jet fuels at temperatures of 1000 and 120 deg C and an oxygen partial pressure of 240 kPa (ca 20 psig). Antioxidants were evaluated in terms of induction period duration and their rates of peroxide formation during the induction period and the initial linear segment of the post-induction time. The global rate constant for the formation of peroxides during the induction period was reduced by the antioxidant, whereas the post-induction rate remained unchanged.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1992
- Accession Number
- ADA260578
Entities
People
- David W. Naegeli
- George E. Fodor
Organizations
- Southwest Research Institute