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Recycle Week: What happens to food waste that is taken for Anaerobic Digestion?

THIS week (17th-23rd October) is Recycle Week, an initiative by WRAP (Waste & Resources Action Programme. This year’s theme is ‘Let’s Get Real’, which aims to challenge perceptions and myths around recycling.

So, let’s get real about food waste – with over one-third of all food produced globally going to waste, finding ways to reduce and recycle this insufficient waste of resources is now essential.

Our focus is on ensuring food waste is recycled with biotechnology. Through the natural process of Anaerobic Digestion (AD), we convert 115,000 tonnes of food waste and organic-based materials into clean, green renewable energy and biofuels.

We have made great progress with recycling in the UK to date, however, it’s important to realise that recycling goes far beyond plastic, paper and metal. The UK alone produces 9.5 million tonnes of food waste in a single year. If more businesses in industries such as hospitality were to promote food waste recycling through companies such as Warrens Group, it would go a long way to reducing that figure.

We treat post-manufacturing residues from the food production industries which cannot be used in foodstuffs primarily for quality, freshness and market presentability reasons. In addition to this we handle food waste from the retail (supermarket sector) which has gone beyond sell-by/use-by dates and is not in sufficiently good/consumable condition.

From the hospitality sector, we handle food preparation waste and leftovers collected as a minimum weekly or indeed more frequently via a tailored bin collection service. In addition to the above Warrens also service schools, colleges, the NHS and MOD facilities on a similar basis.

How does it work?

AD is a natural biological process where micro-organisms break down organic matter to produce valuable renewable resources including biofertiliser and power.

  • The process begins by removing all traces of plastic, glass, and metal before pasteurising the waste to meet stringent regulations.
  • The waste is then transferred to large digestion tanks where anaerobic digestion takes place in a fully sealed air-free environment.
  • Millions of bacteria ‘feed’ on the organic waste to produce a methane rich ‘biogas’, which can then be used for heating and to produce electricity.

Through this process, we are able to generate over 100 million kWh of clean, green energy – enough to power over 20,000 homes for an entire year. The gas and electricity are supplied directly to the national grid as well as a supply of 100,000 tonnes of biofertiliser to local farmers to help grow their crops.