The Era of Return of Waste Plastics to Raw Oil Social Background of the Emergence of Thermal Recycling Technology (1990s)

The Era of Return of Waste Plastics to Raw Oil Social Background of the Emergence of Thermal Recycling Technology (1990s)
In Japan in the 1990s, waste disposal and resource recycling became serious problems at the same time, and waste plastics in particular emerged as a difficult issue: if incinerated, they emit dioxin, and if buried, they do not decompose. The expansion of consumption had put pressure on final disposal sites in various regions, and the methods of burning and burying had reached their limits. Under these circumstances, attention turned to thermal recycling technology, which uses pyrolysis to return plastic to raw oil. When heated to 300 to 500 degrees Celsius in an oxygen-free environment, the molecular chains are broken, and the oil content is converted to an oil similar to gasoline or kerosene, and about one liter of oil can be generated from one kilogram of waste plastic.

In the mid-1990s, small-scale equipment for municipalities and medium-scale plants for companies entered the demonstration stage, and were featured in environmental magazines and administrative materials. The national and local governments were searching for a recycling model in anticipation of the implementation of the Containers and Packaging Recycling Law, and oil conversion technology was expected to both recycle resources and prolong the life of disposal sites. On the other hand, pyrolysis equipment was difficult to operate reliably, and there were many problems, including variations in the quality of the oil produced, corrosion and gas emissions due to contamination with vinyl chloride, and maintenance and management costs. Nevertheless, considering the waste disposal crisis of the time, oil conversion technology was positioned as an important option, and it became the basis for later chemical recycling research.