Stellantis To Develop Tires Using Eggshells

Stellantis has patented an environmentally friendly tire using eggshells as an alternative to traditional materials.

An Italian-American-French conglomerate has filed for protection for an innovative system that integrates organic waste, such as eggshells, into a rubber compound to reduce its negative impact on the environment.

This document, published in the United States Patent Office (USPTO) on January 23, 2025, originally filed in 2023, describes eggshells as a replacement for two fundamental components in traditional tires: carbon black and silica.

Stellantis is working on special “organic” tires

Tires, as they wear, release particulate matter such as soot and silica. According to research published in 2023, these particles make up a significant portion of overall harmful emissions.

Stellantis, therefore, proposes an innovative solution: using calcium oxide (CaO) from eggshells as an alternative filler. Chicken eggshells are 90 percent composed of calcium carbonate (CaCO3). The process of obtaining calcium oxide involves an initial washing phase with acetone, followed by a heat treatment at over 900 degrees Celsius, which causes the calcium carbonate to decompose, releasing carbon dioxide and leaving solid CaO as a residue. In this phase, the calcium oxide is ground into a powder until it reaches a particle size similar to carbon black or silica and is then mixed with rubber and other elements to create a sustainable rubber compound.

It is still uncertain whether this technology will be a commercial success, especially considering that Stellantis is a car manufacturer and not a tire manufacturer. The industry is already looking for more sustainable alternatives, which is key to further reducing the negative environmental impact of the transportation sector. As the adoption of electric vehicles expands, tailpipe emissions are progressively decreasing.

Industry giants are already working on more environmentally friendly materials. Bridgestone, for example, has developed tires for the Audi e-tron GR with 55 percent recycled and renewable materials while introducing natural rubber extracted from desert shrubs for IndyCar racing tires. Michelin announced a collaboration with Hyundai in 2022 to develop environmentally friendly tires, while Goodyear unveiled a prototype tire that reduces the use of petroleum-derived materials.

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