Flash Pyrolysis of High Density PolyEthylene

Abstract

The inert and oxidative flash pyrolysis of High Density Poly-Ethylene (HDPE) is studied up to 20 000 K.s-1, under pressure up to 3.0 MPa and at temperature ranging from 1000 K to 1500 K. These conditions are considered to represent those waited onboard a hybrid rocket engine using HDPE as solid fuel. Recycling applications may also find some interest. The pyrolysis products are analysed by Gas Chromatograph, Flame Ionisation Detector and Mass Spectrometer to quantify the effects of each physical parameter on the HDPE decomposition. The classical products distribution diene-alkene-alkane for each carbon atoms number is shown to be modified at such high temperature because of the pyrolysis of primary products. The pressure effect, which is generally neglected in HDPE pyrolysis studies found in open literature, is proved to be a major factor (up to one order of magnitude on the ethylene mass fraction). The heating rate presents noticeable consequences on the pyrolysis products distribution with a larger formation of light species while heavier ones are favoured under oxidative pyrolysis conditions. The experimental data should serve in the future to improve the accuracy of kinetic mechanisms for later use in numerical computing.

Unsteady Simulation of Ignition of Turbulent Reactive Swirling Flow of Novel Design of Solid-Fuel Ramjet Motor

“…The subscript "sol" denotes the solid fuel and the characteristics of HDPE are as follows: white color, density ρ sol of 940 kg/m 3 , thermal conductivity of 0.38 W/(m.K), A sol of 8750 m/s , E a sol of 130 KJ/mol [32,33]. The pyrolysis rate of HDPE due to heat transfer from fluid domain into the solid surface before combustion (gasification step) and during combustion are treated as a source term affecting the fluid-domain conservation equations.…”

Numerical study on a new design of solid-fuel ramjet combustor with swirl flow

“…and T is the solid-fluid interface wall temperature. These coefficients are taken from [7] to HDPE solid fuel. In order to model the solid fuel pyrolysis in the solid-fluid interface the zeroth order (…”