Breathing life into waste
On the outskirts of Newcastle-upon-Tyne in the North East of England, a confectionery factory is using a centuries old technique to breathe life into waste.
A new anaerobic digestion system at Nestlé’s factory in Fawdon is turning chocolate and sugar confectionery waste from the site’s manufacturing processes into renewable energy and clean water.
Rejected chocolates and sweets that are not suitable for sale or reprocessing, along with waste residues such as starch and sugar are broken down in to small pieces. This mixture is then partially dissolved using the waste liquids from the site’s cleaning processes to create a ‘chocolate soup’.
This ‘chocolate soup’ is then fed into an airtight tank where anaerobic digestion occurs. Anaerobic digestion is the natural process of bacteria breaking down biodegradable material, such as food, without oxygen, and converting it into useful by-products. These by-products are used to meet part of the site’s energy needs.
While the technique itself has been used in agriculture and industry for centuries, what makes the system at Fawdon unusual is that it has been designed to handle a high volume of solid and liquid waste within a short time.
“The system allows us to add tougher residues like starch based compounds to the process, along with reject product and other materials,” says Inder Poonaji, Nestlé UK and Ireland’s head of sustainability.
“As long as the material is biodegradable, the anaerobic conversion process can take place. The waste we are converting here would otherwise be disposed of externally.”
