Environment | Value natural resources
Action3: Expand and diversify renewable resources

Merely reducing raw material consumption (Action 1) and using recycled resources (Action 2) will not be enough to ensure a reliable supply of products and services needed to meet the continuously increasing global demand. By further expanding and diversifying the renewable resources it uses to make its products (Action 3), Bridgestone can help build a truly sustainable society.

The approach to using sustainable materials focuses on balancing resource use with the Earth's capacity. It is acknowledged that switching from non-renewable materials to plant-derived renewable resources alone is insufficient. For instance, Bridgestone is working to diversify its renewable material sources by developing guayule and other alternatives for natural rubber. Additionally, efforts are being made to increase the productivity of cultivated rubber trees, which are currently the main source of natural rubber for tires.

By helping boost the productivity of small farms (see the “Enhancing contribution” section for details), as well as by both improving productivity and diversifying its current supply sources through innovative technological development, Bridgestone is working to ensure the future sustainability of its sources.

Natural rubber accounts for a large proportion of the essential raw materials for tires. Currently, almost all of the natural rubber used in industries is produced from a rubber tree called Hevea brasilliensis. The cultivation areas of natural rubber trees are limited to areas around the equator, and Southeast Asia accounts for 93 percent of the world’s natural rubber supply. To protect tropical forests and reduce disease risk, Bridgestone needs to increase the productivity of natural rubber trees and to research alternative plants that can be grown in wider areas.

Bridgestone has succeeded in producing natural rubber from guayule using commercially scalable techniques, and is conducting research for continued improvement.

Natural rubber is a key component of all tires. But growing and cultivating rubber presents challenges. Specifically, Hevea brasilliensis supply is geographically concentrated, subject to disease and climate change, and labor-intensive to cultivate.

But alternatives are on the horizon. Guayule shows significant promise as a solution to diversify natural rubber supply across different plant species and into various climates.

Guayule is an evergreen shrub in the aster family. The highly drought-tolerant plant is native to the Chihuahuan Desert in northern Mexico and the southwest United States. It accumulates rubber in its bark layer that is almost identical to natural rubber harvested from Hevea brasilliensis. Importantly, guayule does not compete with food crops and is suitable to mechanization. Planting more guayule also could expand green land that contributes to increased CO₂ absorption.

Bridgestone has been investing in a research and development effort focused on guayule since 2012 and has accumulated technologies and knowledge related to its agriculture, processing, and use in tires, including the development of tires with 100% of the natural rubber-containing components derived from guayule. These efforts align with Bridgestone’s commitment for “Ecology: Committed to advancing sustainable tire technologies and solutions that preserve the environment for future generations” stated in the “Bridgestone E8 commitment.”

As a new crop, growing, harvesting, and using guayule requires research to develop new processes. Bridgestone is continuing to establish growing protocols that maximize the amount of rubber produced per acre. The rubber extraction process has been successfully demonstrated and potential end-market uses for the non-rubber co-products are being identified.

In addition to natural, sustainable rubber, guayule processing produces distinct co-products that will provide benefits to other industries. To maximize this opportunity, Bridgestone is building a new partner ecosystem with companies active in agriculture, energy, cosmetics, and other fields. It is also working with nonprofit organizations, funders, governments, and others to fill knowledge gaps, open markets, and reduce risks.

Through open-innovation and co-creation of this exciting biodiversity opportunity, Bridgestone aims to diversify its rubber resources, reduce risks to its natural rubber supply chain, and further contribute to the sustainable production of natural rubber.

Co-development of highly productive varieties of guayule with Versalis S.p.A.

In 2017, BSAM began collaborating with Versalis S.p.A. of Italy to make full use of the latest genetic technologies to develop highly productive varieties of guayule. Its co-development agreement leverages Bridgestone’s leadership position in guayule agronomy, agricultural biotechnology, and manufacturing production technologies with Versalis’ strength in process engineering and market development for renewable materials.

Collaboration on assembly of multiple guayule genomes with NRGene

In 2017, BSAM began a four-year collaboration with genomic big data solutions company NRGene to improve guayule varieties for commercialization. BSAM announced the results of this collaborative project in January 2021: the ability to fully sequence and assemble a guayule genome, making it possible to identify genes for important traits. Bridgestone developed mapping populations that allowed NRGene to construct a genetic and physical map by successfully identifying the correct order of DNA fragments. The joint work also successfully combined multiple guayule genomes to construct pseudochromosomes, paving the way for selecting genes from inherent genetic diversity to breed highly productive varieties of guayule. (For more information, see this news release)

Joint project with Kirin Holdings for technological innovation to increase guayule productivity

Furthermore, Bridgestone is developing new technological innovation to increase the productivity of guayule farms through a joint project with Kirin Holdings. Combining the world-class biotechnologies of Kirin Holdings and the guayule cultivation expertise of Bridgestone, the project aims to deliver the large-scale propagation of guayule plants from high-quality seeds. Bridgestone will field test the modern technology on guayule seedlings grown at its 287-acre Agro Operations Research Farm in Eloy, Arizona. The new technology may also be used to support the guayule breeding process to increase a desired genotype more rapidly for testing and production. (For more information, see this news release)

The raw materials that make up tires are diverse. Among them, many are petroleum-based materials, including synthetic rubbers such as butadiene rubber and isoprene rubber, and reinforcing materials like carbon black. To achieve the goal of “100% sustainable materials,” it is necessary to "replace" these petroleum-based materials with renewable resources. In addition to technologies to expand the use of new renewable resources, Bridgestone also focuses on developing such “replacement” technologies.

Bridgestone, ENEOS Materials Corporation, and JGC Holdings Corporation are accelerating their collaboration towards the commercialization of tires using synthetic rubber derived from plant resources.

This initiative is aimed to improve the sustainability of tire raw materials and contribute to the stable future supply of butadiene. Additionally, using synthetic rubber derived from plant resources will help reduce CO₂ emissions at the disposal and recycling stages of tires. Aiming for commercialization in the early 2030s, the three companies will begin technical demonstrations of tires using synthetic rubber derived from plant resources with a pilot plant by 2028. They will also examine the construction of a supply chain for the synthetic rubber and verify the social and customer value of these tires.

Bridgestone is diversifying the regions where it produces natural rubber while also expanding the range of recycled and renewable materials. While effectively implementing industry-academia collaboration initiatives, Bridgestone strives to utilize innovative renewable materials for natural rubber and organic fibers. Synthetic rubber, carbon black, and other chemicals mixed with rubber that are made from petroleum-based materials are instead synthesized from renewable resources. Here, Bridgestone is working on establishing a research and development framework, basic technologies, and commercialization.