Are we making the most of our Waste?

Don Stewart

The answer to this question must surely be "not yet, but Hampshire is ahead of the game in producing a model strategy for the rest of the country to follow…". Kerbside collections in Hampshire cover both recyclables and household waste including a range of non-recyclable material and are processed in Material Recovery Facilities (MRF) and, as plant comes on stream, in Energy Recovery Facilities (ERF).

Material Recovery Facilities

Targets have been set for some 40 per cent of waste to be recycled by 2010. The MRF currently receives over 80,000 tonnes of material per annum for processing based on a 2-shift, 5-day operation, including the following materials:

• Plastics
• Aluminium and ferrous cans
• Newsprint, magazines, pamphlets
• Packaging
• Cardboard.

The machinery set up to separate out material consists of conveyors to control the flow of material, automatic recognition, disc screens, magnets and current-separators to sort out aluminium cans for separate disposal. Non-recyclables unfortunately still find their way into the cycle and these have to be manually picked and discharged for transfer to an ERF.

Energy Recovery Facilities

The ERF is a new state-of-the-art processing facility for non-recyclable household waste. It is a sustainable long-term alternative to landfill and a 24/7 operation handling over 90,000 tonnes of waste per annum for incineration. "Incineration!" you exclaim, "surely means smoke, greenhouse gases, CO₂ emissions and pollution". Not a bit of it.

Hot gases are cooled in a water boiler which produces steam to drive a turbo-generator producing 8 Megawatts of electricity at 11,000 volts into the National Grid. The gases are 'scrubbed' with lime-milk to neutralise acidic gas. Activated carbon is added to remove pollutants and the gases are filtered to remove particulates. The chimney is fitted with a deioniser and there is no evidence of smoke or pollutants in the emission.

Kerbside collection HGVs (Heavy Goods Vehicles) transfer their loads into an enclosed bunker holding 3-4 days supply to cater for weekends and bank holidays. The waste is mixed and fed by 'Grab' to a feed hopper for the self-sustaining furnace. Metal is separated from the ash which is used for civil engineering works and for building material manufacture.

Benefits

The benefits from the operation of these units in the efficient recovery of materials and energy are important:

• Dependence on landfill substantially reduced and release of methane into the atmosphere avoided
• The dependence on fossil fuels is reduced; a tonne of waste equates to one-third tonne of coal
• Waste is converted to energy
• Reduction in greenhouse gases
• Preservation of raw materials.

Summary

The Hampshire County Council are to be congratulated, under their Material Resources Strategy, in providing on brownfield sites impressive and cost-efficient facilities for the recycling and disposal of our household waste. There is no reason to suggest that the programme to meet the target set for recycling of 40 per cent cannot be met. If there is a weakness, then is not in the operation of these sites, rather it is the complacency and reaction of the householder in exercising more care to separate the recyclables in their wheelie-bins for kerbside collection.

(The author wishes to acknowledge with thanks the help and assistance of VEOLIA Environmental Services (Hampshire) Ltd in arranging for CPRE members visits to the MRF (Alton) and ERF (Chineham) - to see the visit report click the link above.

November 2006