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Going high-tech is becoming cost-effective for MRFs

 

 

 

At one point in the not-too-distant past, many companies must have questioned whether investing in multi-stream MRFs was a worthwhile proposition.

EU regulations demanding material-separated household recycling collections looked like the steady supply of commingled material to MRFs could be a thing of the past.

But after a great deal of political wrangling, commingled collections seem set to continue as local authorities justify their services under what critics see is a loophole in the Waste Framework Directive: that separate collections can be ignored if it is proved they are not technically, environmentally and economically practicable. MRW has reported that, according to the Environment Agency, around 65% of councils now undertake commingled collections (MRW.co.uk/ 10001924.article).

With this background, and if recyclers are to make money in the currently volatile marketplace, the demand for high-quality materials from MRFs is as important as ever. In addition, factors including increasing wage bills, the need for higher throughput, tighter regulations and the MRF sampling regime could lead to businesses choosing to invest in advanced sorting equipment.

Tomra Sorting Recycling makes near infrared (NIR) sensor sorting equipment, typically used to deal with paper fibres and plastic, which has been installed in recycling and waste management facilities in 50 countries around the world. Sales engineer Steve Almond thinks the recent introduction of the National Living Wage will increase the use of NIRs in UK MRFs.

“Wage bills for MRF owners are set to rise by 15% for any staff member over the age of 25,” he says. “Owners have to look at ways of reducing their reliance on manual labour in order to remain competitive.”

The slump in the recycled plastics and paper markets led to a number of companies failing last year, including Closed Loop Recycling and Aylesford Newsprint. But Almond says Tomra now has “a number of orders” for MRF upgrades, including capabilities for increasing plastic separation and paper recovery.

“Mixed plastic prices remain low so MRF operators need to maximise the value of individual fractions. Developments in automated sorting technology are making it possible to achieve exceptional purity results in plastics recycling – from coloured and clear types of plastic such as PET and HDPE to other polymers like polypropylene, polystyrene and PVC,” he says. “With the right combination of automated sorting technology, it is possible to achieve previously unfeasible purity levels of more than 99%.”

Roaf’s Oslo facility

Roaf’s Oslo facility

According to Almond, between 2005 and 2012, MRFs mainly used NIR sensors to recover plastics: “It’s only in the past couple of years that a small number of MRF operators have introduced NIR technology for paper recovery and cleaning, a move that we are likely to see more of in the next few years,” he adds. “This is due in part to MRF operators needing to meet increased purity requirements for recovered paper – 97% for UK customers and 98% for export customers.”

Almond is keen to talk up the opportunities for existing MRFs to increase their use of optical automation. “If the UK is to meet its 2020 recycling targets, plants that are currently being built need to incorporate the latest in automated sorting technology to achieve operational, commercial and environmental efficiencies.”

MRFs currently focus on the four main household recycling material streams that the UK is required to deal with and, assuming the UK does not leave the EU, this looks set to continue. But a WRAP report in 2011 argued that MRFs should increase the number of waste streams – to include items such as aluminium aerosols and beverage cartons – to boost profits (http://bit.ly/1TkPE8V). 

WRAP also found that dealing with fully commingled material was more expensive per tonne than dealing with two-stream material. It estimated that extra sorting costs were £6-£23 per tonne, based on a throughput of 10,000 tonnes a year. It also warned that optical sorting of paper fibre was only justified by high-throughput facilities.

Developments at MRFs go hand-in-hand with local authority contracts, which often involve waste management companies making long-term infrastructure investments. Five years on from the WRAP report and there are signs that companies are now seriously considering taking the plunge.

In December, Finnish tech firm ZenRobotics announced it was entering the UK market with its artificial intelligence robotic waste sorting system, Zenrobotics Recycler (ZRR). This can recover mixed waste including metal, wood, stone, cardboard and rigid plastic fractions from mixed waste streams. UK sales director Mac Borkowski said it “increases sorting efficiency, flexibility and lowers operating costs”.

The McGrath Group is looking into thesystem in order to sort a wider range of materials (MRW.co.uk/8684495.article). And Veolia has already introduced ZRR at a source-separated collection centre in Amiens, France, and indicates that the UK could be next.

Sorting at the Amiens centre is done remotely, with operators using a touchscreen to identify the waste to be ejected from the conveyor belt. Veolia says the system – an industrial prototype – recovers an additional 6% of household packaging compared with manual sorting. If it proves a success it could, in Veolia’s words, “open the way to a new generation of sorting centres” with the ability to handle more types of waste.

Scandinavia seems to be leading the way: not only has Finland developed picking robots, but Norway has developed what may be the first ffully automated waste sorting plant.

Operated by Norwegian firm ROAF and built by Stadler, the Oslo facility opened in 2014 and is run by just a handful of people. It uses NIR units supplied by Tomra to process up to 30 tonnes of black bag residual waste an hour. This produces refuse-derived fuel and recovers plastics including film to 98% purity. It also produces ferrous and non-ferrous metals and some paper products to 94% purity (http:// bit.ly/1pkoqEJ).

At last September’s RWM exhibition, Stadler’s UK director Benjamin Eule said that fully automated MRFs were a feasible goal for the “not too distant future”, claiming the benefits were “reduced head count, lower staff costs, improved productivity and better quality recyclates”.

UK sales manager Trevor Smart says the Norwegian authorities are keen on automation because of high wages and concerns over poor working conditions at MRFs.

“It takes up a lot of space and resource to ensure people are safe, whereas a machine will work 24 hours a day without a break,” he adds. “Logically, more automation will come into it. I still think there is a requirement for human quality control. But as far as for people doing the actual physical picking – having done it myself, I’m not sure it’s a job I’d want to do again – there are technical solutions to that.”

MRFs in the UK usually have only one NIR system, but the ROAF facility has one for every step of the process. “The technology already existed, but we put it together in a slightly different way than you find in the UK,” says Smart. 

Stadler has been talking to UK companies and foresees expansion at existing facilities. Smart says: “Retrofitting anything presents its own challenges. We upgraded an existing Viridor MRF at Canford and it had huge lines of pickers. We had to retrofit a NIR sorter inside a picking cabin, and it had to be boxed in because it’s a piece of mechanical equipment.”

Despite warning that the cost of building a fully automated MRF in the UK is currently prohibitive, Smart insists there is a case to be made for investing for long-term gain: “A lot of people get hung up on the price. An NIR sorter might cost you €200,000 (£158,000), but capital costs are insignificant compared with the operational costs of running a plant during the next 10 years. The cost of producing material per tonne is the key driver.”

Current MRF Performance

WRAP MRF reporting data for July- September 2015 revealed to total tonnage of material entering surveyed facilities in England during the third quarter was 817,851 tonnes. Of this, 606,674 tonnes of paper (including card), metal, plastic and glass was produced.

Output of targeted material

Paper   97.1%

Plastic  91.1%

Metals  94.7%

Glass    92.8%

SOURCE: HTTP://BIT.LY/1NMCMYK

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