Stellantis Patents Eggshell-Based Tire Formula for Sustainability

In a move toward greener transportation, Stellantis (FCA US) has secured a patent for a new tire formulation that replaces conventional fillers with bio-waste materials—specifically, calcium oxide (CaO) derived from eggshells. This innovative approach aims to cut down on the environmental impact of tire dust emissions while maintaining performance.

The Problem with Traditional Tire Fillers – 

Tire treads typically contain fillers like carbon black and silica, both of which help improve durability, traction, and rolling resistance. However, as tires wear, these materials release fine particulate matter into the air, contributing to pollution and potential respiratory issues. A 2023 study found that tire dust is a significant source of airborne particulate emissions, pushing the industry to seek more sustainable alternatives.

Eggshells as a Sustainable Solution – 

Stellantis’ patent details a method for extracting CaO from eggshells, which are primarily composed of calcium carbonate (CaCO3). The process involves washing the shells in acetone and subjecting them to high temperatures—above 1,652°F (900°C)—causing decomposition that releases carbon dioxide (CO2) and leaves behind CaO. This material is then milled to match the consistency of carbon black or silica, making it a viable alternative in tire production.

Performance and Environmental Benefits – 

By incorporating CaO from eggshells into tire formulations, Stellantis aims to balance key performance factors—rolling resistance, wet grip, and wear resistance—while reducing harmful emissions. Rolling resistance directly impacts vehicle efficiency, influencing fuel consumption in internal combustion engine vehicles and range in electric vehicles (EVs). Lowering rolling resistance through sustainable materials could lead to a meaningful reduction in overall vehicle emissions. Additionally, reducing reliance on conventional fillers like carbon black and silica may decrease the industry’s dependence on petroleum-derived and mined materials, further lowering the environmental footprint of tire manufacturing.

The Bigger Picture – 

Stellantis isn’t the only company exploring sustainable tire solutions. Bridgestone, Michelin, and Goodyear have all developed eco-friendly tire materials in recent years, including natural rubber from desert shrubs and recycled materials. As EV adoption grows, reducing non-exhaust emissions—such as tire dust—will be crucial in minimizing the environmental impact of transportation.

While it’s unclear if Stellantis’ eggshell-based tire formulation will make it to production, this patent underscores the industry’s ongoing shift toward sustainability. Whether through bio-waste materials or alternative rubber compounds, the future of tires is poised to be as green as the vehicles they support.

Source: USPTO