What happens after our recycling is collected?
by Dr Amanda Doyle
The UK exports hundreds of thousands of tonnes of plastic waste for recycling, and I had started to wonder if the containers I put in my recycle bin would just end up creating a pollution problem in other countries. I visited the Sherbourne Recycling facility in Coventry along with members of the Warwickshire Climate Alliance and Stratford Climate Action to find out what happens after our recycling is collected and why people in the area don’t need to worry about recycling being sent abroad.
Keeping the recycling in the UK
Sherbourne is a materials recycling facility (MRF) that uses the latest technology and AI to sort different materials collected from residential kerbside commingled recycling bins. This allows it to separate out the plastics, papers, glass and metal with very little contamination. As the sorted product – known as recyclate – has a high purity of 99%, it can be accepted by facilities in the UK who then process it into new products. Conventional sorting facilities have a much lower purity recyclate which is not accepted by UK facilities and results in it being sent abroad.
The MRF opened in 2023 and is a partnership with eight local councils covering 1.5m households. Local councils are required to collect kerbside recycling, but there is no rulebook about what to do with it afterwards which can create problems. Typically, councils must source new contracts with the private sector every couple of years. In order to create a more reliable local recycling system, all five local councils in Warwickshire, along with Coventry City, Walsall, and Solihull have a 25 year partnership with Sherbourne Recycling.
Technologically advanced sorting
Our group were given a tour of the facility and the first thing that struck me was the noise of the machinery – I was glad that the PPE included earplugs.
The tour started with the manual sorting section, where the residue – items that can’t be recycled – is removed at the start of the process. Our tour guide went over to the collection bin to see what inappropriate items had made it today and pulled out a fire extinguisher. I found this quite shocking from a safety point of view, but I can’t say I was entirely surprised. Sherbourne’s residue is not sent to landfill, and is instead sent to a cement kiln to provide fuel for cement production.
We got a peek inside a trommel – a machine that performs an initial separation of items by size – which resembled the drum of a gigantic washing machine. From here the streams of waste are whisked away on conveyor belts to a ballistic sorter, which looked like multiple escalators that move vertically up and down. This separates 2D material – such as cardboard and plastic film – from 3D materials such as cans.
Items are initially sorted by size in the trommel. Credit: Sherbourne Recycling
We were then shown a machine that can separate plastic from paper by allowing the paper to fall over a ledge while the plastic is blown into a tube by air currents.
Moving on to the next stages of sorting along the conveyor belts. Credit: Sherbourne Recycling
The highlight for me was watching the robotic arms removing contaminants on the mixed paper line. The arms can pick out up to 70 items a minute and this where the AI comes in. We were shown a screen of the AI system at work; it uses near-infrared scanners above the conveyor belt to rapidly scan every item and highlights the different types of items in different colours. If something shouldn’t be there, the AI tells the arms to remove it.
The AI has the potential to be programmed to sort materials that are currently not easily recycled. For example, it can pick out soft plastics, but the limited end market in the UK for this type of recyclate means that there are currently very limited places to send it. From 2027, it will be a legal requirement for councils to collect soft plastics and Sherbourne will be ready to sort them. However, there is still a need for more facilities that can process these materials..
I admit to having some concerns about the ethics of AI due to concerns over replacing people’s jobs and also contributing to the spread of misinformation online. However, it also has the potential to be used as a really powerful tool and thankfully that is what’s happening here. There are only five people manually sorting waste and removing the residue – which is fewer people than at a traditional MRF. However, the remainder of the staff are trained as technicians and engineers to manage the machinery and the AI system.
At the end of the tour we were shown the final products destined for the UK paper mill, which are one tonne blocks of paper and cardboard. Some sneaky plastic was evident, including a bottle top. Perhaps those annoying new plastic bottles that keep the top attached are worth it after all.
Setting a benchmark
While our first priority should be to reduce and reuse when possible, for the items that end up destined for recycling we need more places like Sherbourne Resource Park.
Sherbourne is a local initiative, however the company sees itself as setting a benchmark for the recycling industry in the UK. Similar schemes could be replicated in other regions to enable local councils to have better control over their recycling and to pave the way towards a circular economy.
An overall view of the interior of the facility. Credit: Sherbourne Recycling