From Food Waste to Cars: Scientists Create Sustainable Tires Using Eggshells, Tomato Skin

Researchers from Ohio State University have found a way to recycle food waste, specifically eggshells and tomato skin, into car tires, replacing carbon black, a petroleum-based filler used in creating tires.

According to a press release from the university, the scientists created a new filler from a mixture of tomato skin and eggshells. By replacing carbon black with the said mixture, the scientist created a new type of rubber that's stronger and more flexible without sacrificing durability.

The natural rubber tire created from tomato and eggshells is different in color compared to normal tires. It has a reddish brown hue, depending on the amount of eggshell-tomato mix.

Dr. Katrina Cornish, Ohio Research Scholar and Endowed Chair in Biomaterials at Ohio State who has been working on the study, says that this food-based tire will hit three birds with one stone.

The technology will offer a possible solution to three environmental problems: making rubber manufacturing more sustainable, lessening landfill waste and reducing the United State's dependency on foreign oil.

“The tire industry is growing very quickly, and we don’t just need more natural rubber, we need more filler, too, Cornish said. "The number of tires being produced worldwide is going up all the time, so countries are using all the carbon black they can make. There’s no longer a surplus, so we can’t just buy some from Russia to make up the difference like we used to."

Treehugger notes that eggshells and tomato skin are two of the main sources of food waste in the country. Tomatoes distributed in the U.S. are modified to have thick skin to survive transportation. This skin is discarded in manufacturing tomato-based sauces as they are not easily digestible. Americans consume 13 million tons of tomatoes a year.

Meanwhile, egg, which Americans eat 100 billion a year, provides a sturdy material for fillers. Cindy Barrera, a postdoctoral researcher at Cornish's lab, noted that the eggshells' porous microstructure allows a larger surface area for rubber contact.

“We may find that we can pursue many applications that were not possible before with natural rubber," Cornish said.

Other researchers involved in the study include Jessica Slutzky and Griffin Michael Bates.