Eggshells in tires? Stellantis' new patent aims to reinvent eco-friendly driving

Stellantis has filed a patent for a new method of blending waste eggshells into tire manufacturing to make them better and more eco-friendly.

The patent, originally submitted in mid-2023 and published by the U.S. Patent and Trademark Office on 23 January, outlines the process for extracting calcium oxide (CaO) from eggshells.

Performance and efficiency benefits

The company says that using eggshell-derived CaO as a filler could boost fuel efficiency, strengthen grip in wet conditions, and reduce the environmental impact that traditional tires have.

CaO could replace traditional tire fillers like carbon black and silica, making it possible to manufacture using non-renewable materials.

Stellantis said the use of CaO-infused tires can improve fuel efficiency by 3% and reduce rolling resistance by 20% compared to normal tires.

The environmental benefits of this innovation are significant and spread beyond performance enhancement.

Eggshells are widely available as bio-waste. Therefore, incorporating them in tire manufacturing could reduce landfill waste and minimize the reliance on petroleum-based fillers.

Furthermore, tire degradation contributes massively to environmental pollution, with microplastics from worn-out tires polluting oceans and waterways.

Stellantis wants to resolve these issues by replacing harmful synthetic materials with a natural alternative material.

Converting eggshells into tire material requires heating them in extremely high temperatures— about 900°C — to break them down into calcium oxide. After undergoing a milling process, the CaO is then incorporated into the tire compound.

However, Stellantis did not comment on the manufacturing costs or production timelines. It did not say whether the eggshell-infused tires would retain the black color associated with carbon black.