History and Current Status of Saga City Waste Plastic Oil Conversion Plant

History and Current Status of Saga City Waste Plastic Oil Conversion Plant

1996: Start of the oilification plant experiment
The Saga City Cleaning Center and the oil conversion plant in Aioi City, Hyogo Prefecture, collaborated to conduct a demonstration experiment to convert waste plastic into oil. In this project, waste plastic was crushed and sorted in Saga City to remove ceramic and metal fragments, and then pure plastic was sent to Aioi City. The Aioi City plant established a technology to recover 65 kg of synthetic oil from 100 kg of waste plastic, achieving an oil conversion rate of 65%; the processing cost per liter was estimated to be about 110 yen, and the technology attracted attention as a technology for widespread use throughout Japan.

2000s: Legal Improvements and New Technological Development
The Law for Promotion of Sorted Collection and Recycling of Containers and Packaging, which came into effect in 2000, promoted the sorting and recycling of waste plastics nationwide. During the same period, sorted collection became widespread in many municipalities, and material recycling and thermal recovery of waste plastics increased. However, improving recycling rates and reducing costs remained a challenge.

2010s: Introduction of CCU (CO₂ effective utilization)
As part of its biomass industrial city concept, Saga City installed a CCU plant in its waste incineration plant in 2018. The facility separates and collects 10 tons of CO₂ per day generated during waste incineration and sells it to agricultural and algae cultivation businesses in the city. This has successfully created new industries while reducing environmental impact.

The 2020s: The Law for Promotion of Plastic Resource Recycling and Modern Challenges
Under the Law for Promotion of Plastic Resource Recycling, which will take effect in April 2022, Saga City is promoting efforts to collect plastic as a resource. Nationally, ENEOS Corporation, Mitsubishi Chemical Corporation, and other companies are promoting recycling-oriented chemical recycling, in which oil is converted to oil using supercritical water technology and used as a raw material for oil refineries and naphtha crackers.

Summary: Significance of Saga City from Historical Perspective
The trial of the waste plastic oil conversion plant in Saga City began with a demonstration experiment in 1996. Through legal and technological development up to the present, the city has strengthened its efforts for CO₂ effective utilization and plastic resource recycling, and is attracting attention as a model case in Japan. This history symbolizes the challenge of reducing environmental impact and effectively utilizing resources.