MRFs look to the future

Significant changes are underway in the resources and waste sector that will have a deep impact on material recycling facilities (MRFs). How will new legislation and quality expectations force MRFs to prepare for the future? Rob Cole reports 

Robotic arms deftly picking assorted bottles, cans and plastic trays from a recycling stream are no longer the science fiction fantasy of the MRF operator – the future is now. The resources and waste sector has undergone significant change in the past few years, with the introduction of new legislation and policy, shifting markets and changes in public attitudes and behaviours combining to usher in a brave new world for waste and resources. And material recycling facilities (MRFs) will not be immune to this churn – they must be prepared to boldly step into this brave new world.

 Bulk Handling Systems’ Max-AI AQC-C uses robotic sorters and a visual identification system to sort waste
Bulk Handling Systems’ Max-AI AQC-C uses robotic sorters and a visual identification system to sort waste

The question of quality has long been perennial in discussions over MRFs, with the government introducing the Materials Facilities regulations in 2014 to drive up the quality of MRF outputs and ensure that material received by reprocessors at home and abroad met their needs and complied with international waste shipment regulations.

The regulations require all facilities processing more than 1,000 tonnes of material in a year in England and Wales to report on their inputs and outputs – though this stopped short of implementing statutory minimum quality standards, leaving standard-setting to the markets.

However, with little or no inspection of the required sampling regime by the Environment Agency and the continued existence of overseas markets for low-quality, contaminated material outputs, primarily mixed plastics and paper, the dial on quality of MRF outputs has barely moved – the percentage of actual target material in specified output material (SOM) for plastic reported by MRFs in England stood at around 90.1 per cent in Q1 of 2019, compared to 92.1 per cent in Q4 of 2014 when reporting began.

This comes despite the closure of Chinese markets for recycled material at the start of 2018 and the imposition of restrictions in other East Asian markets, such as Thailand and Indonesia, which saw calls for increased quality to meet the specifications of domestic and EU reprocessors.

“When we looked at the MRF portal data at the start of 2019, the reported output quality of plastics, paper and cardboard did not seem to have improved since the start of 2018 when the Chinese restrictions came into force,” says Sam Reeve, CEO of consultancy Resource Futures.

As he says: “If MRF operators can keep finding takers for their output materials at a price that works for them where is the incentive for action?”

A material world

Nevertheless, the pressure on MRFs over quality is ramping up. Public attitudes to recycling and how we deal with our waste, particularly with regard to plastic waste, have experienced a sea change over the past two years – thank you, David Attenborough – and the environmental consequences of low-quality material shipped overseas are no longer beyond the public gaze.
This appetite for action has not gone unnoticed by the political class, and has fuelled renewed government ambition on resources and waste policy, embodied by the Resources and Waste Strategy, which should have a significant impact on the type and amount of material received by MRFs.

Policies such as the introduction of a deposit return scheme (DRS) likely to include metal cans and glass bottles as well as plastic bottles, extended producer responsibility (EPR) for packaging, and a tax on plastic packaging with less than 30 per cent recycled content – dubbed the Plastics Tax – are expected to have a profound effect on the material streams entering MRFs in the coming years.

Proposed legislation concerning consistency of household recycling collections could perhaps be regarded as potentially having the most impact on
the waste streams MRFs receive, with the government preferring multi-stream collections of recycled material at the kerbside over co-mingled collections, separating out contamination at source.

Uncertainty about the final form of these policies notwithstanding, they will remodel the UK’s recycling architecture, drastically changing the composition of waste streams arriving at MRFs. “Making the assumption that DRS targets metal cans and plastic bottles then
these material streams will be expected to virtually disappear from MRF input,” says Reeve. “Each MRF has been designed to sort mixed waste, of which a significant proportion is made up of these materials. The changing composition will impact on the efficiency of the facility and could make certain equipment uneconomical to run.” 

Add to this the general election manifesto promises from all parties to end the export of plastic waste to non- OECD countries and it becomes clearer that what remains in the recycling stream, either from co-mingled household or business recycling collections, will have to be of very high quality to compete with kerbside sorted materials for markets in the UK or EU.

And MRF operators know this – the median MRF gate fee for local authorities has increased once again to £25 per tonne, up from £22 in 2018 where gate fees rose by 47 per cent, while tighter contamination limits for local authority collected waste have been included in contracts as MRFs acknowledge the need to secure new markets and better prices from reprocessors for their outputs.

This apparent shift towards high quality, while not
yet felt by all, will force MRFs to make changes to stay afloat. “The reforms needed to collection systems and investments in MRFs need to catch up quickly with the warm words and the objectives of the Resources and Waste Strategy,” says Ray Georgeson, Chief Executive
of the Resource Association. “High-quality, separately collected recyclate will find a market in the UK or wider EU, the rest – and most of what is currently MRF-sorted – will struggle without significant investment and reform of recycling collections.”


While the exact future of resources and waste policy remains uncertain, with consultations ongoing regarding the headline policies of the Resources and Waste Strategy, investments are being made to future-proof and retro-
fit MRFs, with technology advances largely focused on improving the speed and accuracy of machinery.

Addressing the issue of capacity is a priority, with the amount of waste recycled in England between 2010 and 2017 increasing by 842,000 tonnes to 9.96 million tonnes, meaning “some of the older processing plants that were built ten or more years ago are struggling to cope with the significantly higher throughput”, says Brian Gist, Head of TOMRA Sorting UK.


Waste management company Viridor has invested £15.4 million in refurbishing its Masons MRF in Suffolk, which will increase the facility’s capacity by 10,000 tonnes to 75,000 tonnes per annum through increased accuracy and speed of the machines used, with work expected to be completed in the next month or so.

The new plant installation has seen a significant investment in mechanical recovery equipment, including 11 optical sorters, while 111 conveyors running to a total length of 1,124 metres will join an additional trommel and two balers to separate materials.

The ambitious new policy environment has encouraged Viridor’s investment, with Viridor’s Commercial Director Paul Ringham stating that “increased demand for recycled material in the UK has underpinned Viridor’s investment in recycling technology”. However, those welcoming the recent burst in policy energy after years of stasis, may now be hoping for a period of calm. With the equipment at Viridor’s Masons MRF having a working life of about 20 years, such an investment will require certainty to provide a return on investment.

“To provide an effective solution to local authorities, Viridor requires consistency in the materials its receives,” said Ringham. “Working with our local authority partners, we can design solutions to manage most scenarios. However, we do need assurances that these will not change significantly or frequently. Without this predictability, we may be placed in a position where we would have to repeatedly reconfigure our processing equipment. That is not sustainable.”

The drive for quality will only ramp up technological developments in MRFs. Optical and sensor-based sorting have been at the heart of material sorting in recent years, especially when it comes to different plastic polymers.

Sorting equipment manufacturer TOMRA has made a number of advances in sorting technology, such as the SHARP EYE, which uses a higher light intensity to allow for the sensor to distinguish between the small differences in the chemical properties of PET bottles and PET food trays, allowing them to be separated effectively, and the INNOSORT FLAKE, which is a high-precision flake sensor- based sorting solution that uses RGB cameras and ultra- high near-infra red (NIR) sensors to sort plastic fractions between two and 12 millimetres in size by colour and polymer type.

Innovations such as ‘tag and trace’ technology are also entering the market, which allows brands to ‘tag’ their packaging with a unique PAC code, then allowing the packaging to be ‘traced’ and sorted and reprocessed into identical grades and colours of plastic.

Company Polytag has trialled such technology across households in Wirral, Merseyside, with the support of recycling compliance scheme Ecosurety. Consumers
are able to use an app to scan the packaging’s PAC
code to receive instructions on how to clean and
prepare packaging before it is collected or dropped off
at a designated collection point. The packaging is then processed at a Polytag MRF and returned to the producer as pellets or granulate.

Rise of the robots

Such developments are advancing material sorting, but the technology that will allow MRFs to make a quantum leap in sorting will undoubtedly be AI and robotic technology. TOMRA recently launched new deep learning- based sorting technology called GAIN, which can be added on to TOMRA’s AUTOSORT machines and target and remove polyethylene (PE) silicon sealant cartridges from a PE stream by using camera information. This task was previously performed by hand by workers as AUTOSORT machines were unable to distinguish between the cartridges from the rest of the PE material, but GAIN technology can be used to detect silicon cartridges with an accuracy close to or even higher than that of hand pickers, removing 99 per cent of silicon sealant cartridges.

The deep learning capabilities of the GAIN technology allows “even more advanced accuracy of complex sorting tasks at high throughput rates”, according to Gist, “as well as being more able to adapt to new waste streams or changes to existing waste streams in the future”.

Bulk Handling Systems, an Oregon-based manufacturer, has some of the most innovative and advanced AI material sorting technology on the market, with its Max-AI technology – which has been implemented in the UK at MRFs run by Green Recycling and SUEZ – also using deep learning to identify recyclables and makes decisions over where these materials should go – whether they belong in a particular material stream or if they should be removed.

Chief among this technology is the Max-AI AQC-C,
an AI-powered visual identification system (Max-AI VIS) and robotic sorter, called a CoBot, that is able to make decisions much like a human would to prioritise the picking of materials based on size, value and location. The Max-AI AQC-C is capable of making approximately 40 picks per minute and sorting three material types. Up to four CoBots can be installed per VIS and can work alongside human pickers. The use of the Max-AI VIS allows material composition data to be collected to train the AI prior to the installation of a robot sorter, optimising sorting, while also providing flexibility if processing needs change.

This article was taken from Issue 98

With much material sorting in MRFs still carried out by hand by employees and likely increases in the minimum wage expected to increase labour costs – all main parties’ election manifestos have committed to significant rises – investment in AI and robotics could create operational efficiencies for MRFs and soften revenue squeezes caused by the tightening of markets and changes in waste policy.

“There is certainly going to be a lot of interest in how deep learning algorithms could be used to improve operational performance and to provide solutions for certain sorting tasks which have, to date, relied on manual sorting because humans’ pattern recognition has historically been better than that of machines,” adds Gist.

“There are many UK MRFs where mundane and dirty sorting tasks are still undertaken manually by hand pickers. These tasks could instead be undertaken much more efficiently by sensor-based sorting machines which incorporate deep learning algorithms.”

Though the replacement of human workers to increase revenues may sound cynical – Bulk Handling Systems says of its Max-AI AQC-C: ‘Unlike a manual sorter, the AQC-C won’t get tired, sick, injured or no-show – and it will sort
all day without a break!’ – and speaks to wider concerns about automation and the displacement of workers, as Gist says, MRF work is dirty, unpleasant work, and this is one area where we should welcome the rise of the robots.

Such change has been a long time coming. Improvements in quality have been hard to come by in material sorting, and often it appears that MRFs have been let off the hook, despite the introduction of the Code of Conduct, thanks to a lack of policy ambition and available markets; but no longer. We stand at the start of a path to high quality and now is the time for MRFs to step boldly into the future.