The UK generates around 15 million tonnes of food waste per year, with businesses accounting for just under half of this in the food production sector.
Much of this food waste is currently sent to landfill sites where it is slowly broken down into methane and carbon dioxide, which are both powerful greenhouse gases.
Anaerobic Digestion (AD) technology is increasingly being deployed across the UK, converting waste food matter into bio methane. This is used to generate green energy, which is then exported to the National Grid.
What is Anaerobic Digestion?
Anaerobic digestion (AD) is the breakdown of organic matter in the absence of oxygen by micro-organisms called methanogens. The process of anaerobic digestion provides a source of renewable energy, as the waste is broken down to produce bio gas (a mixture of methane and carbon dioxide).
Anaerobic Digestion Explained
The process of anaerobic digestion provides a source of renewable energy, as the waste is broken down to produce bio gas (a mixture of methane and carbon dioxide).
The bio gas is used to generate electricity and heat to power on-site equipment with surplus electricity exported to the National Grid.
A further by-product of the process is bio-fertiliser (the digestate from the process), which is rich in nutrients such as nitrogen, potassium and other elements required for healthy plant growth and fertile soil.
Bio-fertiliser from source segregated waste can be applied directly to agricultural land where it meets PAS 110 standard.
Biffa and Anaerobic Digestion
We operate a number of food waste treatment facilities in the UK, enabling up to circa 240,000 tonnes of food waste per year to be recycled or reused. We currently have 3 AD facilities, located in Leicestershire, Staffordshire and West Sussex
Our flagship plant in Cannock was opened in April 2011, at an investment of £24million, and has the capacity to handle up to 120,000 tonnes of food waste per year.
This plant is the most efficient food waste processing AD plant in Europe, generating up to 6.5m MW of electricity - enough energy to power 15,000 homes. The plant is best in class, providing a single point waste disposal solution for packaged & unpackaged food waste.
In 2010, Biffa was awarded a contract to design, build and operate an MBT plant with an integrated AD facility on behalf of Sussex County Council.
The facility has a capacity of circa 320kt and is designed to handle the county's residential and business waste tonnage. It is designed to produce refuse derived fuels and recover recyclables in the MBT plant and treat organic waste in the AD plant.
The primary feed stock for our 40,000 tonnes per annum Wanlip plant comes from our mechanical waste treatment facility in Leicester.
Household waste is mechanically processed and then screened and sorted to separate food waste and metals, produce solid recovered fuel and residual materials for disposal.
The extracted food waste is mixed with water to create a slurry, and is then screened and filtered to remove any contaminants.
The plant receives bulk and source segregated food wastes and has been approved for the receipt of category 3 animal by-products.