Before processing composite materials in a pyrolysis plant, the feedstock must have a particle size that is less than 6 millimeters.
The Actual Process…
The Composite particles are fed near the bottom of a pyrolysis reactor together with a flow of hot heat carrier material such as sand, where it is being mixed and goes through pyrolysis.
The produced vapors from the process will go through several cyclones before entering a condenser, where the vapors are quenched by re-circulating oil.
Usually, pyrolysis reactor such as the cone reactor is integrated within a circulating sand system composed of a riser, a fluidized bed char combustor, the pyrolysis reactor, and a down-comer. In this concept, char is burned with air to provide the heat required for the pyrolysis process and making the plant self-sustainable. Overall, oil is the main product of this process.
[Courtesy of: Biomass Technology Group.]
Composite is mixed with a wide range of components, thus pyrolysis will consequently produce a range of products. Pyrolysis depolymerises the polymer chain producing wax, oil and gas derived from the original plastic.
The gas composition produced is dependent on the original plastic used in the composite. For oxygen-containing plastics such as polyester and phenolic resins, the main gases are carbon dioxide and carbon monoxide. For other plastics, higher concentrations of hydrogen and hydrocarbons, such as methane and ethane, are dominant.
The wax and oil are given off as gases during pyrolysis but are condensed downstream. The oil and wax have a high calorific value and can be burnt to provide energy. Alternatively, they can be used as a source of valuable chemicals.
The solid residue left behind after pyrolysis is a friable solid containing the glass fibre and filler, and a small amount of carbonaceous char derived from the plastic degradation.
Section I: Introduction
Section II: Present (YOU ARE CURRENTLY IN THIS SECTION)
Section III: Future
Complete Table of Contents
Reference