posted on 2023-11-16, 18:42authored byWenhao Hu, Zsuzsa Sárossy, Anker Degn Jensen, Anders Egede Daugaard, Peter Arendt Jensen
Pure low density polyethylene pyrolysis
was investigated using
a lab-scale two-stage fixed-bed pyrolyzer with different catalytic
materials in the second reactor for upgrading the vapors. The yields
of gas and char were determined, and the condensed product was thoroughly
examined by gas chromatography–mass spectrometry and thermogravimetric
analysis. The use of different catalytic materials such as HZSM-5,
cement raw meal, calcined cement raw meal, and silicon carbide was
investigated. A wax-rich condensed product (intermediate molecular
weight hydrocarbons) was observed in the following types of experiments:
no catalyst, silicon carbide, and cement raw meal in the second reactor.
The wax was mainly composed of alkanes and alkenes. The use of an
HZSM-5 catalyst and applying temperatures from 350 to 500 °C
in the second reactor highly decreased the chain length of hydrocarbons
in the condensed product and converted the wax into a liquid. When
the second reactor temperature was higher than 400 °C, the main
product components were aromatics and naphthalene. Using calcined
raw meal in the second reactor at a temperature of 600 °C also
led to the conversion of the wax to a liquid product with a large
fraction of cyclic aliphatics.