Speaking yesterday at the Institute of Wastes Management's “Emerging Technologies seminar”, Pete Cumberlidge of Brightstar Environmental explained how Kent County Council has chosen Harrow-based Brightstar as its preferred bidder for a combined recycling and energy recovery plant to help deal with the county's waste. Last month, Kent County Council announced that it had decided to follow a comprehensive strategy to move waste disposal in Kent away from landfill.
Brightstar has put in a proposal which has been accepted by Kent for a Swerf to process waste arising from Dover and Shepway districts. The plant is part of a joint tender with Brett Waste Management to build, own and operate a Swerf at its Shelford landfill site near Canterbury.
The Kent plant will have an initial capacity of 110,000 tonnes per year, with a final capacity likely to be 165,000 tonnes. Brightstar hopes that the plant will be operational in 2004.
In a separate project, Kent County Council has signed a deal to increase recycling and incineration facilities by using the Waste Recycling Group's planned Allington plant near Maidstone. The Allington plant will take up to 150,000 tonnes of household waste a year from Dartford, Gravesham and Swale over the next 25 years.
Kent County Council’s cabinet member for strategic planning, Sarah Hohler, said: “The government has set some tough targets for recycling household waste in Kent and KCC has set its own high standards. We are working with district councils to minimise waste and increase recycling and results have been very encouraging. We want to exploit the full potential for recycling at both the Allington and Shelford plants and will be insisting on this in our negotiations for the revised contract.”
Tube burning
Mr Cumberlidge explained yesterday how a Swerf can receive domestic waste which is either unsorted or combined with a kerbside collection. Brightstar will charge a gate fee of around 35 a tonne.
Mr Cumberlidge said that there are three parts to a Swerf – waste pre-treatment facility, gasification and electricity generation. The pre-treatment facility processes unsorted waste in a sterilizing autoclave. The waste pulp is then separated into component streams through a series of screens, trommels and magnets, similar to an existing materials recycling facility. The metals and heavy plastics are recycled and the glass and grit are processed for re-use.
The remaining pulp-like material is converted into electricity using gasification which converts the pulp into a synthetic gas called syngas. The pulp is fed into a metal tube which is heated from the outside, as there is no air in the tube the contents is not burned. Gas is created as well as some emissions. Because the material is not directly burnt, the company considers the process to be gasification rather than energy from waste although it currently comes under incineration legislation.
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