A technology capable of processing one ton of plastic waste daily to produce lubricant raw materials has been developed in South Korea.
The Korea Institute of Industrial Technology (KITECH) announced on the 5th that a team led by Principal Researcher Shin Myung-chul of the Low Carbon Emission Control Research Division has successfully implemented a process for continuous input of plastic waste and continuous recovery of output products.
Pyrolysis is a technology that decomposes carbon-containing organic materials at high temperatures in an oxygen-free environment to produce useful raw material components. When plastic waste undergoes pyrolysis, vapor is generated, which is then cooled and condensed to yield pyrolysis oil, wax, and non-condensable gases. Pyrolysis oil can be used as a raw material for various petrochemical products, including plastics.
However, existing facilities had limitations requiring the removal of "pyrolysis char," the internal solid residue, after processing raw materials before proceeding to the next stage. In such cases, the reheating process after shutdown could increase sticky wax components, causing blockages within the equipment. Additionally, varying amounts of wax mixed into the oil changed the viscosity of pyrolysis oil each time, hindering commercialization.
The research team solved these problems by establishing a "continuous pyrolysis system" that operates without interruption from raw material input through reaction to product recovery and refinement. They developed a "continuous discharge system" combining a screw-type conveyor with special shut-off valves at the bottom of the facility, enabling automatic discharge of pyrolysis char while preventing external air infiltration. The team also prevented wax buildup by utilizing non-condensable gases generated during the process as a heat source to maintain consistent internal temperatures.
A staged cooling method for vapor generated during pyrolysis was also applied, allowing wax components to be separated and recovered first while selectively extracting high-purity pyrolysis oil.
Furthermore, byproducts from the pyrolysis process, which were previously disposed of in landfills, were designed for recycling into activated carbon or conductive carbon materials.
"We have confirmed that the continuous process can treat plastic waste without interruption and that the produced pyrolysis oil can be applied as base oil for gear lubricants," said Principal Researcher Shin Myung-chul. "We plan to commercialize this through demonstration and follow-up research."
