Turning food waste into energy

Did you know that since 2014, none of our waste has gone to landfill?

We take sustainability seriously, which is why we have so many behind-the-scenes processes you might not know about. From sourcing all of our produce locally and upcycling wherever we can to encouraging you to use sustainable alternatives in our cafés and canteens through our loyalty card scheme, there's so much to know! Learn everything in our sustainability booklet. 

Tackling food waste is just one of the many ways we keep our campus' sustainable through food, read on to uncover exactly how we do it...

Turning our food waste into renewable energy

Thanks to Suez, 100% of our kitchen food waste goes to an anaerobic digester and turned into renewable energy (pretty cool, right?).

What is it? 

Anaerobic digestion is an alternative way of composting food waste while also producing renewable energy and avoiding carbon emissions. A completely natural process dependent on the micro-organisms that digest organic waste, it takes place in a sealed tank with no oxygen. 

How does it work?

It all takes place in a special reception hall of an anaerobic digestion facility, where the food waste goes through an interesting series of steps...

1. The food waste must be pre-treated to remove contaminants - such as packaging - and diluted with water. Then it is heated to 70ºC for an hour to kill all pathogens.
2. The waste is then fed into the anaerobic digester. Like composting, the bacteria break down the waste and covert it into biogas and a residue which is called digestate. 
3. The gas produced is used to generate electricity and heat. 
4. Water removed from the digestate in a centrifuge (a device that uses centrifugal force to subject something to a specified constant force) can be reused in the process. The digestate can even be used as a biofertiliser to improve soil after maturing because of the nutrients it contains!

Turning our cooking oil into biodiesel

There are so many ways food waste can benefit the environment and be reused, which is why we're always thinking about the little things. Since January 2021, we have turned over 2400 litres of cooking oil into biodiesel by working with Olleco - the UK's leading refiner of used cooking oil.

Every litre saves 2kg of CO2e, which is the equivalent of charging your phone...

To find out more about our sustainability mission, click here. Don't forget to check out our sustainability booklet too!

Contact:

Follow us @ualcatering for more updates.