Can all plastics be pyrolyzed?

Plastic pyrolysis is a popular method among plastic recyclers for converting waste plastics into useful resources such as fuel oil, gas, and carbon black. However, not all waste plastics are suitable for pyrolysis.

Types of plastics unsuitable for pyrolysis include:

1. Polyvinyl chloride (PVC): Commonly used in pipes, flooring materials, and packaging, PVC has a high chloride content. Pyrolysis releases large amounts of hydrogen chloride gas, which is highly toxic and corrosive, posing a significant threat to the environment and human health.

2. Polyethylene terephthalate (PET): Commonly used in the manufacture of beverage bottles, food containers, and even textile fibers, PET easily forms large amounts of waxy byproducts and releases harmful benzene gas during pyrolysis. Benzene is a known carcinogen, and its presence is extremely detrimental to human health.

Important considerations when pyrolyzing waste plastics include:

• Detailed sorting and pretreatment: Before pyrolysis, remove unsuitable plastics and impurities to ensure the effectiveness and safety of the pyrolysis process.

• Precise control of pyrolysis conditions: The pyrolysis temperature and duration directly affect the composition and quality of the products.

• Waste Gas Treatment: To mitigate the negative environmental impact of toxic gases and particulate matter emitted during pyrolysis, an effective waste gas treatment system is required.

• Residue Management: Solid residues left after pyrolysis must be properly disposed of in accordance with environmental protection principles to prevent secondary pollution.