You probably get rid of your egg shells by throwing them into the nearest garbage can—an option that's both quick and free–but imagine if you had to dispose of the shells from 1.5 million eggs each week. According to The Economist, that's the situation that Pankaj Pancholi found himself in. Pancholi, the founder of Just Egg—a UK-based hard-boiled egg company—was spending about $64,000 each year to have shells properly buried at a landfill. So, he cooked up a cost-saving plan: Pancholi began working with the chemistry department at the University of Leicester to find a way to turn the shells into reusable material.
First, he and the chemists developed a method for cleaning the shells. (Because of the way the machines at Just Egg's factory work, bits of egg are often left in the shells during the peeling process.) Cleaning involves using conveyor belts to deliver the shells to tanks, where they meet with water and rotating blades. The chopped shells are then washed in a solvent before being left to dry. During that stage, both the water and the solvent are recycled.
After drying, the former egg shells are crushed into a powder that can be added to plastics in order to make them more durable. But that might not be the material's only use. The scientists say that the flakes from the recycled shells could have medical applications in the future, potentially as wound dressing.
On an individual level, turning egg shells into shell powder probably isn't feasible. Composting them during breakfast cleanup could be a worthwhile alternative.
[h/t The Economist]