Why PET and PVC Are Unsuitable for Pyrolysis Processing?

 

Plastic pyrolysis recycling solution

Thermal decomposition technology for plastics is emerging as a vital solution to tackle waste plastic challenges. As a leading producer of solid waste processing equipment, DOING's pyrolysis machine transforms assorted waste plastics into valuable outputs: fuel oil, carbon black, and syngas. This approach overcomes the drawbacks of conventional mechanical recycling via an oxygen-free, high-heat decomposition process, effectively turning plastics into energy-derived products with a resource recovery efficiency exceeding 95%.

 

Plastic pyrolysis oil yield

That said, it's crucial to recognize that pyrolyzing PET proves economically unviable owing to the intricate nature of its outputs, while halogen-laden PVC can yield extremely toxic dioxins. Consequently, these plastic varieties are ill-suited for pyrolysis. Let's explore in greater detail the reasons behind the unsuitability of PET and PVC for pyrolysis.

 

PET finds widespread application in food packaging and drink bottles thanks to its transparency, low weight, and ease of recycling. Yet, when PET undergoes pyrolysis, it presents major obstacles. In the thermal breakdown procedure, PET often results in waxy residues and toxic vapors like benzene—a recognized carcinogen that poses severe risks to human well-being. This stems largely from PET's chemical makeup, featuring ester linkages that exhibit high reactivity. Under elevated temperatures, these ester bonds experience thermal breakdown, producing an array of detrimental compounds, such as acetaldehyde.

 

Beyond emitting hazardous materials, PET is susceptible to hydrolysis under intense heat conditions. This hydrolytic process additionally fragments PET's molecular chains, yielding compounds that endanger human health. Together, these elements render PET not just inefficient for generating viable resources via pyrolysis but also a potential hazard to both the ecosystem and public safety.

 

PVC stands out as unsuitable for pyrolysis chiefly because its polymer structure incorporates substantial chlorine content. In the course of pyrolysis, chlorine reacts with hydrogen to form highly aggressive hydrogen chloride (HCl) vapor, which inflicts severe damage on machinery and escalates upkeep expenses. Moreover, the pyrolysis of PVC can spawn extremely poisonous dioxins alongside other perilous byproducts, endangering the surroundings and human health, while complicating and inflating the costs of output handling. Furthermore, the oil derived from PVC pyrolysis cannot serve directly as fuel or chemical feedstock due to its elevated chlorine levels and subpar quality; similarly, the gaseous emissions and solid leftovers prove challenging to repurpose effectively, leading to dismal economic returns from the overall pyrolysis operation.

Raw plastic materials of pyrolysis machine

 

If you're considering launching a venture in plastic pyrolysis, allow me to highlight the plastics that work well for this process. These encompass PP (Polypropylene), PE (Polyethylene), PS (Polystyrene), and ABS (Acrylonitrile Butadiene Styrene). Such plastics possess robust chemical compositions that enable their smooth transformation into premium fuel oil and carbon black through pyrolysis.

Raw materials of pyrolysis machine

For example, PP and PE appear commonly in everyday items like plastic bags, storage containers, and wrapping materials. When fed into a pyrolysis machine, these materials deliver an outstanding oil extraction rate. Take, for instance, our client in India who set up two 15-ton plastic pyrolysis machines. Utilizing PP and PE as input materials, they secured an oil output of around 85%, with merely about 10% carbon black. This initiative has delivered substantial profits to the client, underscoring the practicality and financial promise of pyrolysis when applied to appropriate plastic categories.

DOING pyrolysis machine manufacturer

With close to 15 years in the solid waste recycling sector, DOING delivers customized recycling strategies for diverse input materials. Our pyrolysis machines are engineered to optimize resource extraction while curbing ecological harm. For more in-depth insights into our pyrolysis methods and the plastic varieties amenable to processing, don't hesitate to reach out to DOING. Based in Zhengzhou, the central hub of Henan Province in mainland China, our firm is conveniently positioned for those in the solid waste recycling field. We invite visits and questions from individuals eager to delve into eco-friendly waste handling options.