Journal of Chemical Engineering of Japan, Vol.39, No.10, 1057-1064, 2006
Modeling and simulation of a non-isothermal tubular thermal cracker
A 2-dimensional model for thermal cracking of ethane under laminar flow, conditions has been established. Based on a molecular mechanistic model for ethane cracking, the model consists of eight mass balance equations along with energy balance and momentum balance equations. This set of coupled partial differential equations is solved numerically by using finite difference backward implicit scheme. The species concentration and temperature profiles in radial and axial directions are predicted with variation of properties with temperature and composition. The model predicts maxima in the concentrations of propylene and acetylene within the reactor. The simulations for the effect of operational parameters on product distribution and temperature are also carried out. The parameters-space time and wall temperature and their range of variations are considered. Wall temperature variation is taken from 950 to 1100 degrees C and space time conditions are taken from 0.2 to 0.45 s. An increase in space time and/or wall temperature results in higher ethane conversion.
Keywords:modeling;thermal cracking;partial differential equations;finite difference;operational parameters