Premier's monumental move for diversion
An ambitious project has just gone live in Tyne & Wear, where commercial and municipal waste diversion technologies will sit side by side for a more integrated solution. Dean Stiles reports
Plant installation for the first phase of Monument Park was completed at the end of last year. The facility has an initial capacity of 100,000tpa and will process commercial waste, extracting cardboard, paper, plastics, wood and metal for recycling. Initial tests indicate that as much as 50% of all waste delivered to the facility will be diverted from landfill and recycled.
Building and civil engineering work for the site cost £1.3M - plant and equipment added £750,000 to the investment cost. Netherlands-based manufacturer BOA supplied the picking station as a turnkey project, together with an impress M-75 multi-material, pre-press baler incorporating a twin spiked-roller bottle piercer and producing 720mm high bales.
The picking station, supplied by IFE, incorporates waste screen and magnetic separation, while JCB supplied waste handling plant including a JS160 excavator with grab and a Loadall 520-40.
"The picking stations are state-of-the-art and the manual picking stations are fitted out to a high standard to maintain a good working environment for the staff," says Malcolm Johnson, treatment director at Premier. "Stations are covered and under positive air pressure to keep out dust. We also have a stereo system for the staff."
Feedstock for the site is from Premier's existing commercial waste contracts that range in duration from 12 months to several years with businesses across the North East extending into Northumberland and Yorkshire.
"Initially we think we can get 50% recycled, rising to 65% as we progress - we will always aim to get more," says Johnson. "Some of the loads will be pre-segregated by the customer at their premises, some will be done by the mobile plant at the site. Others by the magnetic separators, and some by hand at the picking stations."
Aerobic digestion planned
The site also has planning permission for 12 aerobic digestion towers to allow municipal solid waste treatment in the future - a development that will "massively" increase capacity, according to Johnson, and enable the company to branch further into the local authority municipal market. Premier currently handles household waste in the North East through a contract with Durham County Council. This is processed by a Premier Advanced Recycling Centre (Parc) that is achieving 65% diversion from landfill.
Two Parc towers are already in operation at Thornley, Durham. A third tower - commissioned in 2006 in conjunction with Defra's new technologies programme - provides an additional 25,000 tonne capacity. This latest tower is built from pre-cast concrete sections, is 16.5m high with a 15m diameter and has 50% greater capacity than the first two towers.
"At present, the three towers manage around 62,000 tonnes a year with 37,000 from towers 1 and 2 combined and 25,000 from tower 3 - obviously there is scope for significant development," says Johnson. "In December we ran a series of short-term residence tests and managed to reduce residence time in tower 3 to as low as 65 hours (2.7 days), but typically 80 hours (3.3 days). This allows much greater volumes of waste to be treated."
He stresses that the Parc tower uses aerobic digestion, not methane-producing anaerobic digestion. The Parc process is similar to that occurring in a compost pile, with the heat generated by the microbes sterilising and stabilising the waste in the tower. This material is then fed through various segregation equipment to separate glass, non-ferrous and ferrous metal, and plastic bags. The composted biogenic fraction can be used as a soil conditioner.
"We use a range of established segregation techniques to separate out the material from the sterilised and stabilised waste stream coming out of the tower," explains Johnson. "The material segregation equipment is separate from the Parc tower - this means that we can invest in new separation technologies as they become available and easily integrate them into the production."
The residue from the Parc process, a composted waste output, can be used to produce a topsoil for brownfield and landfill restoration. "One of the more interesting uses is to grow coppiced willow trees as a biofuel," says Johnson.
"We have six sites in the northeast growing willow. Once this is harvested, it will be sold into the SembCorp wood burning power plant. The benefit of this is that we are using brownfield land to grow the wood. So we are not taking away farm land from food production."
Dean Stiles is a freelance journalist