The continued need for plastics necessitates an effective solution for processing and recycling polymer wastes. While pyrolysis is a promising technology for polyolefin recycling, an experimental apparatus must be designed to measure the intrinsic kinetics and elucidate the chemistry of the plastics pyrolysis process. To resolve this issue, a modified Pulse-Heated Analysis of Solid Reactions (PHASR) system was designed, constructed, and evaluated for the purposes of polyolefin pyrolysis. Experimental results demonstrated that the new PHASR system is capable of measuring the millisecond-resolved evolution of plastic [e. g., low-density polyethylene (LDPE)] pyrolysis products at a constant temperature. The PHASR system was shown to be capable of producing a repeatable, fast heating time (20 ms) and cooling time (130-150 ms), and of maintaining a stable temperature during reaction. A second, Visual PHASR system was developed to enable high-speed photography and visualization of the real-time pyrolysis of LDPE.

Continued demand for polyolefins can be met by recycling plastic materials back to their constituent monomers, ethylene and propylene, via thermal cracking in a pyrolysis reactor. During pyrolysis, saturated polyolefin chains break carbon−carbon and carbon−hydrogen bonds, yielding a distribution of alkanes, alkenes, aromatic chemicals, light gases, and solid char residues at temperatures varying from 400 to 800 °C. To design a pyrolysis reactor that optimizes the chemistry for a maximum yield of light olefins, a detailed description of the chemical mechanisms and associated kinetics is required. To that end, the reaction kinetics of isothermal films of low-density polyethylene (LDPE) have been measured by the method of "pulse-heated analysis of solid reactions", or PHASR, which allows for quantification of intrinsic kinetics via isothermal reaction-controlled experimental conditions. The evolution of LDPE films from 20 ms to 2.0 s for five temperatures (550, 575, 600, 625, and 650 °C) was characterized by measurement of the yield of chromatography-detectable compounds (

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract