From Waste Plastics to Recycled Resources: An Analysis of the Industrial Value of Chemical Recycling

The "white pollution" caused by plastic waste has become a global environmental challenge. In this context, chemical recycling, as an emerging technological pathway, is gradually demonstrating its unique scientific logic and industrial value. It not only converts waste plastics into high-value products such as base oil, combustible gas, and carbon black but also fundamentally advances resource circularity, reduces reliance on fossil feedstocks, and achieves dual environmental and economic benefits. This is not mere speculation but is deeply rooted in the molecular characteristics of plastics themselves. As a leading enterprise in waste plastic chemical recycling equipment, Niutech has pioneered a new path for chemical recycling through its independently developed waste plastic pyrolysis technology, enabling sustainable plastic recovery.  

1. The Molecular Nature of Plastics: The "Regenerative Potential" of Carbon-Hydrogen Structures  

Common plastics such as polyethylene (PE), polypropylene (PP), and polystyrene (PS) are essentially high-molecular compounds composed of carbon and hydrogen. These polymers resemble long chains formed by countless repeating basic units, with variations in chain length, branching, and connectivity giving different plastics their distinct physical properties.  

For example, polyethylene molecules consist of ethylene monomers linked in a straightforward, regular linear chain, while polypropylene features methyl side branches, making its structure slightly more complex. This carbon-hydrogen-based chemical composition makes plastics inherently akin to petroleum—the hydrocarbon fuels and chemical feedstocks derived from oil refining share a similar molecular foundation with plastics. Therefore, waste plastics possess the potential for "traceable regeneration" at the chemical level: by breaking their molecular chains through specific methods, they can be reconverted into petroleum-like products, achieving a closed loop from waste to resource.  

2. The Core of Chemical Recycling: Deconstruction and Reassembly of Molecular Chains  

Chemical recycling essentially involves the precise dismantling and reconstruction of plastic polymers.  

Pyrolysis lies at the heart of this process, typically conducted under high temperature, pressure, or with catalysts. Depending on the reaction mechanism, it can be categorized into thermal pyrolysis and catalytic pyrolysis. Thermal pyrolysis relies on high temperatures to directly break carbon chains, while catalytic pyrolysis employs catalysts to lower the energy barrier, enabling selective chain cleavage under milder conditions and improving the yield of target products.  

During pyrolysis, long-chain polymers gradually fragment into shorter segments and can further degrade into small-molecule gases. The regulation of reaction conditions directly influences product distribution: medium- to low-temperature pyrolysis favors the production of longer-chain hydrocarbons, which can be purified into base oil; high-temperature pyrolysis generates substantial combustible gases such as methane and propane; and in limited-oxygen environments, partial carbonization can produce carbon black. For instance, Niutech’s equipment primarily employs medium- to low-temperature pyrolysis technology, converting waste plastics into pyrolysis oil and combustible gas.  

3. Recycling Characteristics of Different Plastics: Tailored Approaches for Specific Polymers  

The behavior and outputs of chemical recycling vary depending on the type of plastic.  

- Polyethylene (PE): With its simple structure and balanced carbon-hydrogen composition, PE is easily pyrolyzed to yield high quantities of liquid hydrocarbons.  

- Polypropylene (PP): Pyrolysis of PP generates significant amounts of olefins such as propylene, which can serve as both fuel and chemical feedstocks for recycling. Its liquid products also hold potential as base oil.  

- Polystyrene (PS): Containing benzene ring structures, PS pyrolysis facilitates the recovery of styrene monomers for feedstock regeneration, while also producing combustible gas.  

- Polyvinyl Chloride (PVC): Due to its chlorine content, PVC is more complex to process. The release of hydrogen chloride during pyrolysis can corrode equipment and pollute the environment, often necessitating pre-treatment dechlorination. Although currently more costly, chemical recycling of PVC is gradually becoming feasible with technological advancements.  

Niutech’s pyrolysis technology and equipment are not limited to single plastic types but enable continuous pyrolysis of mixed waste plastics, significantly enhancing feedstock versatility and holding practical importance for waste plastic treatment. For example, a plastic recycling project in Denmark utilizes Niutech’s pyrolysis technology and equipment to process sorted plastic waste from municipal solid waste—a complex mixture—effectively converting it into pyrolysis oil, which is further refined into naphtha for synthetic resin production, achieving chemical circularity.

Chemical recycling of waste plastics is not merely a technological breakthrough but a critical component of the circular economy. Leveraging the inherent carbon-hydrogen chemistry of plastics, it transforms environmental burdens into resource value through precise molecular deconstruction and reassembly. With continuous technological optimization and strengthened policy support, chemical recycling is poised to become a key pillar in plastic waste management, driving society steadily toward a sustainable future.