I confess, I am a lover of chocolate. I prefer dark, bittersweet—the higher the cocoa content and bitterness the better. For me a dream trip is a tour of a chocolate-making factory where any rejected, “not fit for the store” chocolate can easily find a home in my mouth!
Unfortunately, my dream is not going to manifest exactly the way I would like, but for the good of our planet, Nestle’s chocolate factory in Fawdon, in northeastern England is turning all that unfit-for-consumption chocolate and sugar waste into renewable energy.
They make a chocolate soup by combining the rejected pieces of chocolate and other sweets, with starches and sugar, broken down into small pieces, plus waste liquids from cleaning processes. This chocolate soup goes into a large, airtight chamber and undergoes anaerobic digestion, meaning that natural bacteria in an oxygen-free environment breaks down the soup changing it into a useful by-product. In this case, the leftover chocolates and confectionery will feed the factory’s energy systems.
This anaerobic digestion system is not something new—farms have been using it for years, but this is the first time that the process is taking a very high volume of by-product and converting it into a useful product in a very short period of time. Not only does this new process help to reduce Nestle’s energy costs, but it improves the environment. According to inder poonaji, Head of Sustainability for Nestle UK and Ireland, “The waste we are converting here would otherwise be disposed of externally.”
Nestle Fawdon is now covering 10% of its plant-wide energy needs with the bio-gas produced from its chocolate and sugar waste. It is expected that its greenhouse gas emissions will fall by an equal percentage. The anaerobic digester is also improving water quality, meaning that water released from the plant is practically pure.
All of this did not come easily. It took quite a bit of money and trial and error. They began with a pilot project using a smaller digester for three months, experimenting with the quantities and types of bacteria to find the most effective. The huge upfront investment means that it will take around four years before the factory begins to earn a return, but for Nestle it is more than worth the wait. Now the digester is converting 200,000 liters of liquid waste and four tons of solid waste daily, becoming one of the 72 Nestle worldwide sites to achieve zero waste disposal status.
And I thought it was just about the chocolate.