Positioning of the Project
As part of the NEDO Green Innovation Fund, technological development aimed at converting used tires back into chemical feedstocks has been positioned. The target is the chemical recycling of waste tires, assuming a pathway different from conventional thermal recovery where tires are used as fuel.
Two conditions exist in the background.
・Long-term increase in tire demand
・Strengthening of decarbonization policies
With the increase in vehicle ownership, global tire demand is expected to continue rising. At the same time, most raw materials are petroleum-derived, creating challenges in aligning with carbon neutrality policies.
Current waste tire processing has a high proportion of fuel use, and in terms of resource circulation the amount returned as materials is limited. Chemical recycling is positioned as an attempt to change this structure.
Technical Structure
The assumed process consists of staged steps in which waste tires are decomposed and returned to chemical feedstocks.
Process outline
・Pyrolysis of waste tires
・Refining of pyrolysis oil
・Conversion to petrochemical feedstocks
・Monomer production
Main chemical products expected
・Butadiene
・Isoprene
・BTX (benzene, toluene, xylene)
・Recovered carbon black
This structure assumes integration with existing petroleum refining and petrochemical facilities. Tire-derived pyrolysis oil is refined and used as part of naphtha-based feedstock.
Consortium structure
Bridgestone
・Waste tire processing
・Pyrolysis oil generation
・Material evaluation
ENEOS
・Petroleum refining
・Conversion to petrochemical feedstocks
・Chemical production
Through the division of roles between the tire manufacturer and the petroleum company, integration with existing infrastructure is achieved.
Change in Industrial Structure
Conventional waste tire utilization follows the structure below.
Waste tires
→ Fuel
→ Energy recovery
In the current concept, a material circulation loop is formed.
Waste tires
→ Pyrolysis oil
→ Petrochemical feedstock
→ Synthetic rubber
→ Tires
For this loop to function, multiple conditions are involved.
Material conditions
・Removal of impurities such as sulfur and nitrogen
・Stabilization of pyrolysis oil quality
・Physical properties of recovered carbon black
Industrial conditions
・Compatibility with petrochemical facilities
・Waste tire collection systems
・Integration with chemical markets
Institutional conditions
・Resource circulation policies
・Carbon neutrality policies
・Waste regulations
Research and development is assumed to progress to the demonstration stage in the 2020s, after which commercialization is considered.
A structure in which tires are returned again to tires as materials may create a new supply chain at the boundary between the rubber industry and the petrochemical industry.