Molecular-level modeling investigation of n-decane pyrolysis at high temperature

A small-scale molecular reaction model has been established to predict the behavior of thermal cracking n-decane based on the experimental study of n-decane pyrolysis under supercritical conditions (4 MPa, 480-720 °C). A developed experimental method of electrical heating tube (2 mm inner diameter) was used experimentally to obtain the detailed local chemical compositions and temperatures along the reactor tube. Gas chromatography was used to analysis the pyrolysis products, and the calculated density and corresponding residence times along the reactor tube were reported. The overall n-decane decomposition could be represented by a first-order reaction with frequency factor and activation energy of 6.209 × 1015 s−1 and 59.4 kcal/mol, respectively. The experimental products and calculated thermophysical properties along the microchannels of a heat exchanger could be effectively simulated by using the molecular reaction model, consisting of 16 species, a first-order reaction and 21 secondary reactions among the primary products. The performance of the reaction model in reproducing the experimental data was reasonably good even the cracking conversion up to 93%.