Thermal Cracking of n-Nonane

Abstract

An experimental investigation of thermal cracking of n-nonane in a laboratory-scale flow reactor was carried out. The reactor was operated at atmospheric pressure. Experimental data were obtained for the temperature range of 650-750°C and the nonane flow rate varied from 0.13 mol/hr to 1.3 mol/hr. An analysis of the overall kinetics of decomposition indicated that the order of the decomposition reaction and the frequency factor and the activation energy for the decomposition rate constant are approximately 1.0, 2.01 X 1 014 sec-1 and 63 kcal/g-mol respectively. The measured product distributions agreed reasonably well with the ones predicted from Rice's theory. Woinsky's model has been found to correlate approximately with the results of the present study. The empirical method of severity function correlation applies well to the products of nonane decomposition.Cracking of hydrocarbons has been extensively studied since the beginning of this century. During the 1930's, interest developed significantly in these reactions. At this time,

High pressure pyrolysis of n-heptane

“…The activation energy of the reaction of ethyl radical with n-hexane has been reported as 10,400 cal mol À1 [36] and that of reaction (15) as 41,700 cal mol À1 [7]. Therefore, a lower temperature and higher partial pressure will favor the second-order reaction (14), resulting in more ethane and less ethylene. The study carried out with pure n-heptane (no inerts) by Appleby et al [8] also supports this observation, as they obtained higher selectivity of ethane in comparison to others.…”

“…Numerous studies have been published on the pyrolysis of n-paraffins such as ethane, propane, n-butane, n-heptane, n-decane, n-hexadecane etc. at atmospheric pressure [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The main thrust in these studies has been to enhance the yield of low molecular weight olefins.…”

Experimental study of hydrocarbon structure effects on the composition of its pyrolysis products

“…Studies of homological hydrocarbons were performed mainly for linear and non-linear alkanes [29,[35][36][37][38], but they were not aimed at developing the structure-selectivity relationships. Their goals were mainly the research of radical reactions mechanism including the confirmation of Rice-Kosiakoff theory [3,16,26,29,34,35,39], the estimation of reaction order and reaction rates of pyrolysis reactions [3,7,13,16,24,26,29,34,[39][40][41][42], or the effect of temperature on the selectivity of products formation [3,13,16,24,26,29,34,35,38,41].…”

The importance of temperature rise time in pyrolysis kinetic studies

“…For most micro-sample kinetic studies to date, the assumption has been made that the reactants reach the reaction temperature instantaneously. In some cases where it is suspected or known that this is not true, an average reaction temperature has been calculated (Kunzru et al, 1972;Kumar and Kunzru, 1985) by using the equivalent reactor volume concept developed by Hougen and Watson (1947). These assumptions can be justified for determining the kinetics of slow reactions.…”