A PARTNERSHIP between TOMRA Recycling and specialist commercial food waste disposal company, Swancote Energy, has resulted in the first application of optical sorting technology in an Anaerobic Digestion (AD) facility in the UK.
In October 2021, Swancote Energy invested in an AUTOSORT® unit from TOMRA Recycling at its state-of-the-art 75,000tpa anaerobic digestion (AD) facility in Bridgnorth, Shropshire. The facility produces renewable energy is from a combination of commercial food waste and purpose-grown energy crops. Combined heat and power plant generators convert the biogas into electricity and heat, with the electricity fed directly to a local aluminium smelting company. The new AUTOSORT® unit is enabling Swancote Energy to recover recyclable plastic packaging from commercial food waste which can then be used in the production of new food-grade plastic packaging.
The plant’s infeed stream comprises of palletised food waste from multi-national food manufacturers, retailers, distributors and small independent businesses. Many different types of food waste are processed at the plant, including loose, liquids and palletised. The infeed stream contains a wide range of packaging materials such as plastics, tins and glass. Swancote Energy uses a number of different mechanical and automated processes to recover all recyclable products for recycling, including glass, tin cans, aluminium products and plastics.
Following the installation of TOMRA’s AUTOSORT® unit, Swancote Energy can now process 50,000 tonnes per annum of palletised food waste while ensuring the rigid plastic packaging – including HDPE, PP and PET bottles, tubs, trays and pots – is all recovered for resale. The organic matter is removed first before the material goes through a hot wash prior to being optically sorted. The AUTOSORT® unit is the final stage in the process of depackaging of the food. Once recovered, the recyclable plastic packaging is sold on to food-grade plastic recycling facilities, allowing Swancote Energy to provide its customers with a closed loop recycling solution.
The AUTOSORT® unit combines near infrared (NIR) and visual spectrometers (VIS) to accurately and quickly recognise and separate different materials according to their material type and colour, extracting high-purity high-value end fractions. At Swancote’s facility, the unit is programmed to target and sort rigid plastics by colour and polymer from the infeed stream, with the target fractions being HDPE, PP and PET.
Edward Davies, Director of Swancote Energy, comments: “Prior to installing the AUTOSORT® unit, the plastics we recovered from our food waste destruction process were simply biproducts of the process which were sent for incineration. Now, with the unit in place, we are able to separate all recyclable rigid plastics which has not only provided us with an additional revenue stream, but also helps us to fulfil the UK Plastic Packaging Tax (PPT) which came into effect on 1st April 2022. Based on the success of the first AUTOSORT® unit, we may look to invest in more TOMRA equipment as new markets open up following the introduction of the PPT.”
Brian Gist, Head of TOMRA UK, adds: “This is a really interesting project as it’s the first time that our technology has been used to recover plastics from commercial food waste. There is very little plastic in household food waste but the volumes of plastic packaging in the infeed stream that Swancote Energy processes are high so there is a very strong commercial argument for recovering them. Edward and his team were already familiar with sensor-based food sorting systems through our TOMRA Sorting Food division so they reached out to us when looking for a solution which would help them turn their plastic packaging from an incineration bi-product into a valuable commodity. Now, they are able to sell on the recovered plastics and help close the loop on plastics recycling by keeping material in the chain.”