Pyrolysis of Polyolefins Using Rotating Arc Plasma Technology for Production of Acetylene

Abstract

Polyolefin, as one of the most widely used macromolecule materials, has been one of the most serious threats to the environment. Current treatment methods of waste polyolefin including landfill, incineration, and thermal degradation have suffered from severe problems such as secondary pollution and the generation of other toxic substances. In this article, we report for the first time a high-efficiency method to produce high-value C2H2 from polyolefins using a rotating direct current arc plasma reactor, using polyethylene and polypropylene as feedstocks. The essence of this method is that a reductive atmosphere of pyrolysis enables a thermodynamic preference to C2H2 over other carbon-containing gas and the rotating direct current arc plasma reactor allows for a uniform distribution of high temperature to ensure high conversion of polymers. Thermodynamic simulation of product composition was performed, and the effect of plasma input power, polyolefin feed rate, and working gas flow rate on the pyrolysis results was experimentally investigated. It was found that, with proper parameter control, approximately complete conversion of carbon in polyolefin could be obtained, with a C2H2 selectivity higher than 80% and a C2H2 yield higher than 70%. These results not only create new opportunities for the reuse of polymer waste, but are also instructive for the green production of C2H2.

Keywords

• plasma
• rotating arc
• polyolefin
• pyrolysis
• acetylene