in Morbihan, a couple of farmers are bringing this white gold back to life with many uses

Perched in the cabin of her telescopic forklift, Florence Chedaleux, guided by Paul-Gilles, her husband, moves several hundred kilos of a coarse white powder: crushed eggshell. Based in Lizio (Morbihan), between Rennes and Vannes, the farming couple used to receive quantities of it which they spread to reduce the degree of acidity of their Breton land. But in 2003, the authorities banned the use of these unsterilized shells due to the risk of spreading salmonella, a bacteria frequently present in raw eggs. They then came up with the idea of ​​sterilizing and transforming these shells to give them a second life.

Paul-Gilles remembers that “at the beginning, the tests were done in the family oven”, Florence ended up finding the right process to sterilize them and separate them from their thin internal membrane. A few years of tests, analyzes and an administrative odyssey later, the farm accommodates warehouses and the new secret machine: Terremo’logic was born in 2018.

The small Breton company today processes 6,000 tonnes of eggshells per year, coming from three surrounding “crackeries”. These structures buy eggs from breeders in order to transform them into egg products – whites, yolks and beaten eggs – packaged and ready to be used for the agri-food sector. Of the 14 billion eggs produced in France per year, nearly 40% end up not in our refrigerators but in our cupboards (industrial pasta, biscuits and brioches). The other side of the story is the enormous quantity of shells they generate.

A natural fertilizer

Most often destined for landfill, joining the compost in recycling centers in the best cases, eggshells nevertheless represent a resource with interesting characteristics. Composed mainly of calcium carbonate, the outer shell is sterilized and reduced to a thick powder by Paul-Gilles and Florence. Thus transformed, it is sold as a natural amendment – ​​a material to be spread on land – to replace lime, to “maintain the soil and regain a good pH”, as explained by Damien Lequitte, a dairy producer located near Lizio. .

The research of this ingenious couple does not stop there. With the help of actors in the region, they create bioplastic composed of 15 to 30% shell, petroleum-free, durable and recyclable, transformed into egg cartons, toothglasses and trash cans. As for the internal membranes, with their high content of nitrogen, proteins and minerals, they recycle them into fertilizer. With the help of AgWI, a company specializing in plant nutrition solutions, they are preparing to transform them into biostimulants, an initiative subsidized by the European Union. A project among others for the company which is looking for new outlets. But certain sectors have already turned to this white treasure. Several pet food manufacturers offer shell powders as a dietary supplement to meet their calcium needs. The construction sector is not left out: paint, tiles, building blocks, interior decoration… eggshells are found everywhere.

The power of collagen

It is not the outer shell which arouses the most desire but rather the vitelline membrane, this thin organic layer stuck to the inside of the shell, rich in collagen and hyaluronic acid, two substances very popular in cosmetics. According to research firm Global Market Insights, the egg membrane market exceeded $119 million in 2022 and could well reach $284 million in 2032.

Enough to whet the appetite of investors. Because this product has advantages in other areas. Researchers in Dublin (Ireland) used it to isolate rare earth elements in water and extract these substances, which are essential for recyclable batteries. This use could represent an alternative to mining, which is both costly and polluting.

At the University of Saskatchewan, located in western Canada, researchers have also created granules capable of depolluting water from eggshells combined with other substances. Very green promises for a white gold that was hiding before our eyes.