Temperature coefficients for reactions of OH radicals with alkanes between 300 and 1000 K

✍ Scribed by R. W. Walker

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 481 KB
• Volume: 17
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550170603

✦ Synopsis

Recently, Atkinson et al. have developed a more sophisticated approach than simple additivity to determine group rate constants a t room temperature for reactions of OH radicals with alkanes. In this article, use is made of reliable experimental data a t room temperature and at 753 K to determine temperature coefficients for these reactions. Evidence based on experiment is cited in support of the expression k = A T ' e -E R T a s a suitable quantitative expression for the variation of k with temperature between 300 and 1000 K for OH attack a t any particular specific group in an alkane. Values are given for A and E for a number of groups found in both linear and branched alkanes. With highly branched alkanes, steric effects may limit the use of even the more sophisticated additivity approach used here. Use of the group values permits the calculation of both the overall rate constant for OH + alkane, the agreement with the limited amount of experimental data available being very good, and the proportions of each species of alkyl radical formed in t h e overall attack. Such information is vital to quantitative modeling of combustion processes currently being carried out extensively. The values given in the article are recommended for use over the temperature range 300-1000 K.