This innovative process directly converts mixed plastic waste into high-value chemical raw materials, such as propylene and ethylene. 

With an investment of approximately CNY 1.5 billion, the project delivers an expected annual output value of CNY 1.243 billion and tax revenue of CNY 265 million through advanced chemical recycling.

Its carbon emissions are only one-fifth of traditional petrochemical processes, setting a global benchmark for chemical recycling of solid waste. 

Client Challenges

The Dongyue Chemical project is tasked with processing a variety of mixed plastic waste streams. These include low-value plastics that have been sorted and cleaned from agricultural films, paper mill waste plastics, municipal solid waste, and aged garbage. 

The input sizes range from 100–400 mm with densities as low as 100 kg/m³. These materials typically contain impurities such as PVC, presenting significant challenges for solid waste processing equipment:

• Efficient Shredding and Particle Size Control: It is essential to shred mixed plastic waste from 100–400 mm to 30–40 mm, and ultimately to 2 mm, to ensure uniformity of feedstock for catalytic pyrolysis.

• Adaptability to Complex Materials: The equipment must be capable of processing low-density, soft plastics and impurities like PVC without disrupting downstream processes or causing issues related to chlorine content.

• High Throughput and Cost Efficiency: The system is required to meet a contractual throughput of 6 t/h while optimizing per-ton processing costs to ensure economic feasibility.

• Continuous and Stable Operation: The equipment must support uninterrupted production to avoid downtime in the intensive solid waste recycling process.

Harden Machinery’s Solution

Harden Machinery, a global leader in solid waste processing equipment, delivered a customized shredding solution featuring six SG2200RP single-shaft shredders and supporting discharge conveyors. 

These single-shaft shredders were pivotal in meeting the project’s stringent requirements, offering superior performance through the following features:

• High-Efficiency Shredding and Precise Particle Size Control

• Advanced Single-Shaft Shredders: The SG2200RP single-shaft shredders, equipped with integrated screening systems, efficiently reduced mixed plastic waste to 30–40 mm (exceeding the contractual 100 mm requirement). This ensured optimal feedstock for subsequent processing stages, including secondary shredding to 20 mm and final pulverization to 2 mm.
  

• Adjustable Cutting Units: The shredders feature customizable cutting gap adjustments, enabling precise optimization for diverse material properties, such as the flexibility of agricultural films or the impurity content of paper mill plastics, ensuring consistent output and high shredding efficiency.

  
  

• Robust Adaptability to Complex Materials
  

• High-Torque Variable Drive System: The SG2200RP single-shaft shredders incorporate a high-inertia, variable-torque drive system, enabling seamless processing of low-value plastics sorted and cleaned from agricultural films, paper mill waste plastics, municipal solid waste, and aged garbage. This design prevents material jams and ensures operational stability.
  

• PVC Tolerance: By integrating with Dongyue’s CPDCC process, Harden’s shredders eliminate the need for pre-sorting PVC, reducing the burden on downstream chlorine capture systems and enhancing overall process efficiency.

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• High Throughput and Cost-Effective Operation
  

• Superior Throughput: Each SG2200RP single-shaft shredder achieves a capacity of up to 20 t/h, with the six-unit system easily meeting the contracted 6 t/h requirement, providing robust support for continuous production.
  

• Cost Optimization: The shredders’ four-sided cutting blades extend tool life, significantly reducing maintenance costs. Combined with energy-efficient operation, this lowers the per-ton processing cost, enhancing the project’s economic viability.
  
  

• Stability and Intelligent Design
  

• Reliable Continuous Operation: The modular design and intelligent control systems of Harden’s single-shaft shredders ensure long-term operational stability, minimizing downtime risks in Dongyue’s high-demand production environment.

• Efficient Maintenance: Adjustable cutting units and modular components enable rapid maintenance, reducing service time and boosting overall productivity.

Project Outcomes

Harden Machinery’s solid waste processing equipment played a critical role in the successful ignition of Dongyue Chemical’s one-step mixed plastic waste recycling project on April 8, 2025, and its transition to production preparation by May 2025. Key outcomes include:

• Seamless Process Integration: Harden’s single-shaft shredders delivered consistent 30–40 mm feedstock from sorted and cleaned mixed plastic waste, including agricultural films, paper mill plastics, municipal waste, and aged garbage, enabling smooth integration with downstream drying, granulation, and catalytic pyrolysis processes.

• Significant Economic Impact: The project’s projected annual output value of CNY 1.243 billion was supported by Harden’s cost-efficient shredding, reducing raw material processing costs and enhancing profitability.

• Environmental Benefits:  By enabling efficient waste processing, Harden’s equipment contributed to reducing 1 kg of landfill or incineration per 1 kg of plastic processed, with the project’s carbon emissions at just one-fifth of traditional petrochemical processes.

• Industry Leadership: As a key component of Dongyue’s project, Harden’s single-shaft shredders contributed significantly to establishing the initiative as a flagship in Jieyang’s green petrochemical industry, fostering a closed-loop, high-value, low-emission supply chain.

Client Testimonial

A Dongyue Chemical project manager stated: “Harden Machinery’s SG2200RP single-shaft shredders have been instrumental in processing our diverse mixed plastic waste streams. Their efficiency, adaptability, and cost-effectiveness have ensured stable feedstock preparation, significantly contributing to our project’s success. Harden is a trusted partner in our green revolution.”

Conclusion

Harden Machinery's single-shaft shredders and customized waste processing solutions have been vital to Dongyue Chemical's mixed plastic waste recycling project. With efficient shredding, adaptability, cost-effectiveness, and reliability, these shredders have contributed to the project's success and set a practical standard in the waste processing industry. Harden is dedicated to supporting the circular economy by partnering with clients to tackle environmental challenges and promote sustainability.