A research team from the Korea Institute of Energy Research (KIER), led by Dr. Chong-Pyo Cho of the Energy Convergence System Research Department, has successfully developed South Korea’s first continuous oxy-fuel combustion-based gasification process for converting waste plastics—including hard-to-recycle thermoset resins—into high-quality syngas.
Amid growing concerns over climate change and resource depletion, the recycling of plastic waste is becoming increasingly vital. In 2023, the global waste plastic recycling market was valued at around 100 trillion KRW and is projected to grow at an average annual rate of 8.1%, reaching approximately 173 trillion KRW by 2030.
Plastics are generally divided into thermoplastics, which can be reshaped through heating, and thermoset plastics, which harden irreversibly after curing. Thermoset plastics are prized for their heat and chemical resistance, making them ideal for use in automotive components and electronic devices. However, these same properties make them extremely difficult to recycle, often resulting in disposal by landfilling or incineration—both of which contribute significantly to environmental pollution.
Addressing this challenge, Dr. Cho’s team developed a gasification system that uses oxy-fuel combustion to convert mixed thermoset plastic waste into syngas, a critical input for hydrogen production. This marks the first time a continuous oxy-fuel process has been successfully established in South Korea for this purpose.
To improve process efficiency and enable continuous operation, the team implemented oxy-fuel combustion control technology to eliminate nitrogen from the air, reducing heat loss. They also incorporated a regenerative melting furnace system that retains heat within the gasifier, enabling the system to consistently reach temperatures of up to 1,300°C.
This high-temperature environment is essential for minimizing tar production—a viscous, sticky byproduct that typically impairs continuous operation. Traditional gasification methods operate below 800°C, leading to large amounts of undecomposed tar and requiring expensive purification systems. In contrast, the new process maintains high temperatures throughout, reducing tar generation to just 0.66 mg/Nm³—an impressive 93.4% reduction compared to standard commercial syngas production requirements—without the need for additional purification.
The system was tested using a pilot plant in Yongin, which can process one ton of mixed thermoset plastic waste daily. It demonstrated a hydrogen production capacity of 0.13 kilograms per kilogram of plastic waste, indicating strong potential for scaling.
In recognition of its innovation, the research team secured three domestic patents and filed one international patent, paving the way for future commercialization. Plans are already underway to scale the system up to a 2-ton-per-day processing capacity.
This achievement represents a significant step toward a more sustainable plastic waste management strategy. By dramatically improving gasification efficiency and reducing the cost and complexity of syngas production, the technology offers a promising solution for transforming difficult-to-recycle plastics into valuable energy resources using fully domestic capabilities.
By Impact Lab
