Kinetic Modelling of High Density PolyEthylene Pyrolysis: Part 1. Comparison of existing models

摘要

High Density Poly-Ethylene (HDPE) is one of the possible solid fuels to be used in hybrid rocket propulsion, despite its low ability of rapidly producing combustible gas. This drawback may be balanced by the auto-ignition delay of the pyrolysis products, which would conduct to the increase of the heat release rate in the engine and thus to the one of the regression rate. Six single and multi steps HDPE pyrolysis mechanisms from the literature are compared in this paper to determine their ability to predict the production of byproducts and the consumption of HDPE. Transient pyrolysis is observed from 650 K to 823 K at atmospheric pressure and discrepancies up to a factor 7 are found between these mechanisms, despite they are all derived from experimental data. One mechanism is finally selected to conduct a parametric study in more realistic operating conditions for hybrid rocket, up to 1700 K and 100 bar. Identifying and quantifying pyrolysis products are necessary to study their combustion with another detailed mechanism.