14 February 2018 by Joshua Doherty

PTT calorific value ‘very important’ for Viridor EfW plant

EXCLUSIVE: Plastic pots, tubs and trays are “a very important part of the calorific value” required to supply the ‘thermal power station’ at Runcorn run by Viridor, the Greater Manchester Waste Disposal Authority has been told.

The comments on calorific value come in a report to the authority which suggests that burning the plastics for energy recovery is more efficient than recycling them. The report has been drawn up against the background of the closure of Chinese markets for mixed plastics and action by government to try and secure end markets for recycling of plastics.

Viridor’s energy from waste plant at Runcorn (pictured) enjoys high calorific feedstock in the form of plastic pots, tubs and trays

And members of the GMWDA have also discussed the potential for the authority to step in and manage waste plastics from other local authorities through the residual value contract (RVC) facility in Runcorn. This could have meant plastics, such as pots, tubs and trays (PTT) from other councils burnt at Runcorn but this is not a recommendation or idea that is being taken forward by GMWDA.


The report explains that PTT are not collected by the authority because of limited end use markets and because in many cases “the energy required to release trapped ‘raw materials’ exceeds the benefits that could be used to release value by thermal means”.

Also considered at the meeting were higher than expected contamination levels in commingled recycling streams.


Also in the report, despite what was described as “extensive education and communications activities”, GMWDA members are told that contamination within the commingled recyclate stream is typically running between 15 to 20%. This compares to the 5% originally anticipated in the design of the facility.


Although plastic pots, tubs and trays help Viridor’s Runcorn plant, the company said it offers a range of options to councils

“Members will be aware that in order to ensure quality of recyclate materials are as good as possible we currently employ three additional staff, who work in both the tipping hall and also in the initial sort cabin at the MRF,” the report stated.

The GMWDA deals with approximately 1.1 million tonnes of waste produced each year in households across Greater Manchester, including the districts of Rochdale, Salford, and Bolton. Currently, the authority only accepts plastic bottles through its commingled stream.


Viridor indicated that it offers options to local authorities for residual waste. A spokesperson for the company said: “Viridor, with the UK’s largest network of 300 plus waste and resource management facilities, including recycling and energy recovery, is ideally placed to provide its more than 150 local authority and major corporate clients with a range of options based on their specific needs.”


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