From costly egg waste to profitable product

Everyday, several hundred egg product factories process approximately 1 million eggs each. This production generates extensive volumes of eggshells and egg trays, which has resulted in a significant waste handling challenge.

The Danish engineering company Sanovo Environmental Solutions A/S has developed an innovative way of handling the waste fraction from the egg product industry. In the unique process, both the eggshells and the egg trays can be treated at the same time by using the egg trays as fuel to burn the eggshells. The incineration residual of this process constitutes burnt limestone or quicklime, a commodity chemical widely used, for example, in the building sector.

This technology allows these materials, earlier considered as cost-intensive by-products, to be processed into a sellable product. In addition, the process energy can be exploited in the production.

In the process, a mixture of eggshells and egg trays is incinerated under controlled conditions in a boiler system. Due to the very high purity of the starting material – the eggshells – and the composition of the egg trays, the incineration residual burnt limestone is of a quality comparable to or even exceeding commercial limestone qualities.

This is confirmed by the Danish producer of conventional burnt lime – Dankalk. Instead of being a competitor, they have decided to be the main purchaser of the burnt lime produced by this system.