Wedesday 7th October 2008
Twenty members and their guests attended this afternoon presentation and tour of the Integra South East Energy Recovery Plant in Portsmouth. Joanna Dixon Communications and Education Officer, Veolia Environmental Services, gave an illustrated talk outlining the plant and the waste management systems employed by the company in the Hampshire area. It was interesting to see how the Hampshire approach to the problem is somewhat different to that for West Sussex as outlined in the talk given to the RCEA in September.
The presentation was followed by a tour of the plant where we were able to ask many questions of Joanna and Kate our guides, and the plant Control Room Staff who were also able to demonstrate many aspects of the plant on their screens.
The following few paragraphs are an extract from the Veolia Publicity Material (printed booklets and web pages) outlining the Hampshire approach to waste management and the plant at Portsmouth.
At the end of the 1980s it became evident that Hampshire was facing a waste disposal crisis. Landfill space was rapidly running out, incinerators built in the 1970s were not going to meet EU emission regulations, indeed the Portsmouth plant was closed early in 1995 and waste levels were continuing to rise.
Traditionally household waste has been landfilled. Instead of landfilling, three Energy Recovery Facilities have been developed in Hampshire: Integra South East at Portsmouth, Integra South West at Marchwood near Southampton and Integra North near Basingstoke.
Integra South East is capable of processing 165,000 tonnes of waste per year and recovers heat energy from the waste to produce steam. This is used to generate up to 14MW of electricity, which is supplied to the National Grid. This is sufficient to power 14,000 local homes for the life of the facility.
Household waste is delivered to the Energy Recovery Facility where it is tipped into a bunker. One of the crane grabs lifts the waste and places it into the feed hopper. It then drops down a feed chute onto the grate. The action of the grate turns the waste to allow it to burn fully. The burnt-out ash passes through the ash discharger onto an ash handling system, which extracts metal for recycling. The remaining ash is sent for recycling or disposal. Hot gases produced in the combustion process pass through a water-tubed boiler where they heat the water to become steam. A turbo-generator uses the steam to produce electricity for export to the National Grid. The gases from the boiler go through an extensive flue gas cleaning process, which starts with a gas scrubber where lime milk is injected to neutralise acid gases. Activated carbon is added to remove dioxins, urea is added to remove oxides of nitrogen and finally a bag filter takes away the remaining particulates. The resulting material known as Air Pollution Control Residue (APCR) is used to neutralise other wastes at a licensed site. The cleaned gases are finally released into the atmosphere through the chimney.
When household waste is burnt in a modern purpose built Energy Recovery Facility, various environmental objectives are achieved. It is truly a win-win solution. Waste is managed in a sustainable manner. Energy is recovered from the waste. Dependence on landfill is reduced. Release of methane from landfill is avoided (methane being a greenhouse gas many times more potent than carbon dioxide). The use of fossil fuels is reduced, a tonne of solid waste equates to one third of a tonne of coal The benefits of recovering resources for all.
Richard Norton
