How will a DRS impact UK MRFs? (Part 2: Glass)

Article 2: The impact of glass on DRS

A Deposit Return Scheme is planned to be implemented in Scotland during 2023 which includes PET, metal and glass drinks containers. Scotland has set a target to achieve 90% recovery of DRS materials by Q3 2024. England is considering a DRS which includes PET and metal drinks containers only.

Over the last few months, at SortFlow, we have had the opportunity to model and measure the impact of DRS on MRF processes for several facilities across the UK. We have measured the financial impact and, in some cases, evaluated how to tune or upgrade the process to compensate for the loss of revenue that DRS represents at MRF level.

The DRS system is expected to differ between Scotland and England. Glass is part of the scheme in Scotland but not in England. This has of course a huge impact on the quantity of material processed by MRFs.

Commercial and technical impact

Glass can average between 20% and 60% MRF waste inputs. Logistically collecting and processing this quantity of material is of course significant. When considering the impact of glass on MRF sorting processes, we can make the following observations at a commercial and technical level:

1) In 2022, MRF glass value ranges between -£23/tonne and £8/tonne based on prices observed by Letsrecycle.com.

If you consider a MRF processing 50,000 tonnes per annum with 30% glass in the input, revenue would be -£345,000 in the worst-case scenario and £120,000 in the best-case scenario. The delta is significant, and for the majority of MRFs, what it means is that processing glass will typically net MRFs a fairly sizeable loss (not considering gate fee revenue).

2) MRF process capacity varies broadly across the UK. Some are designed to process a few tonnes an hour while the biggest ones will do 20 tonnes per hour or more. If those MRFs have to process 30% less material, does it mean that they will be able to process 30% more material recyclables to make up for the lost glass? Unfortunately, it is not the case. Typically, glass is one of the first materials recovered in the sorting process. As a result, it is the capacity of the next equipment on the main line that could help us determine how much non-glass material can be processed. If there is an ONP (paper recovering) screen placed behind the glass-breaking screen for example, its maximum capacity will give us the first clue as to what is the maximum quantity of material that can be processed at the

But plant bottlenecks can be very complex to identify. They can be at different stages of the process. It can be in some cases even transfer conveyors. And so, to determine infeed capacity, it is necessary to consider the capacity of all equipment in the process.

For the MRFs we have modelled, we have unfortunately not identified a major throughput uplift when glass is removed from the equation. As surprising as this may seem, it is in a way fairly easy to explain: MRF processes so far have accounted for glass being present in the material by design, and the glass-breaking screen rarely appears to be holding back a plant’s maximum throughput capacity.

So what about the net effect?

From a MRF perspective, not having to process glass, is positive overall: less material to handle and no net loss to account for. These are all beneficial. In addition, glass breaks into small pieces, it is highly abrasive and can find its way everywhere, into any recovered products. It could even result in selling products for a higher price potentially, for example being able to sell paper or card to certain papermills that require superior quality material with no glass contamination.

When you consider all this, the negatives of not processing glass are the loss of gate fee revenue resulting from the MRF receiving less material and any costs to reconfigure the process equipment to optimising the processing of materials without glass. For our 50,000t/year MRF, processing 30% glass in a pre-DRS world – assuming for the sake of this example that all of this glass is removed from the stream post-DRS – this means a 30% reduction in gate fee revenue. With a gate fee set at £50 per tonne, this would mean a gate fee revenue shortfall of £750,000.

But gate fee is a cursor that is by design there to be adjusted and assure that MRF finances remain in the black. To what degree it can and should be adjusted varies on a case-by-case basis.

Luc Mallinger