Go Zero

Two ‘burning ‘ questions: the ultimate recycling of our residual waste by generating electricity and using biological sources to produce a carbon neutral transport fuel.


Waste is tipped into a holding area (1) where it is picked up by grabs and dropped into a hopper (2).
The waste is pushed gradually into the incinerator (3) which runs at a temperature of 750 degrees Celsius.
Heat from the burning waste is used in a boiler (4) and steam from this is piped to a turbine generator to create electricity.
The heaviest ash falls into a collection point (5) and is passed over with an electromagnet to extract metal content for recycling.
Flue gases containing fine ash then pass through a scrubber reactor (6) to treat acid pollutants such as SO2 and also dioxins.
The gases then pass through a fine particulate removal system (7) and are released through the chimney stack (8).


The UK government has launched a review of its waste strategy. Among the proposals is a plan to increase the amount of rubbish that is incinerated instead of being sent to landfill sites.

The BBC News website looks at the arguments for and against the use of incinerators.

 
Q. How much waste is currently incinerated?
Around 9% of municipal waste in England is currently incinerated. The south-west has the lowest proportion of incineration, with less than 1% being burned. The West Midlands burns the most, sending 31% of the region's waste to incinerators.
The vast majority of municipal waste is still sent to landfill sites. Around 72% of the 29.1 million tonnes of rubbish was buried in 2003/04.

Q. Why are environmentalists and campaigners against more incinerators?
They say incineration encourages more waste because incinerator operators need to have a constant level of waste to keep the fires burning. To meet this demand, campaigners say, local authorities abandon recycling and waste reduction plans.
However, government figures show that recycling and composting of waste increased in 2003/04 by 3.3% to 19%. Campaigners are also concerned about pollution from the smoke and ash, which they say is a health risk to local residents.

Q. What are the possible health risks?
The main concern surrounds pollutants found in the ash left in the incinerator and emitted from the chimney. These include dioxins, acid gases, nitrogen oxide, heavy metals and particulates.
It is the dioxins contained in the gases from the chimneys that attract most concern because they are suspected of causing cancer. The Environment Agency in England and Wales, and the Scottish Environment Protection Agency regulate and closely monitor the emissions from incinerators. The introduction of tighter EU regulations in 1996 saw many of the older incinerators close down because they could not meet the stricter standards.

Q. What are the benefits of incineration?
Nearly all of the municipal waste that is burned in the UK is used to generate electricity, in what is called "energy from waste" (EfW). If the waste is not burned then it is likely to end up in a landfill site, which is considered the least environmentally friendly option.
Ash from incinerators can be used in the construction and road building industries. Environmental groups say that although incinerators generate electricity, it does not save energy in the long run because the waste is not recycled. This means more raw materials have to be produced to replace the burnt material.

Q. How much waste does the UK incinerate in comparison to the rest of Europe?
Around 17% of waste in the EU is incinerated, almost twice the UK level. Denmark, seen by many as one of Europe's most environmentally conscience nations, burns around 53% of its municipal waste.
At the other end of the scale, a number of countries - including Ireland and Greece - do not incinerate any of their waste.


Car firms and investors greet UK biofuel

It has long been known - and not only by environmental enthusiasts - that bioethanol made from, say, the grains otherwise used to make whisky is perfectly suited as an automotive fuel.

"You drink the best and you drive the rest," quips Graham Hilton who works for Wessex Grain's bioethanol subsidiary Green Spirit Fuels. Racing drivers have been using it for years, and many of them swear by it.

"It's best for the environment and it doesn't lack power," says British touring car racer Fiona Leggate, who races a biofuel-powered Vauxhall. "I'd love to see it as a mainstream fuel."

The future of motoring
It is a vision shared by Somerset county councillor Paul Buchanan, who is involved in an ambitious biofuel experiment where local police will drive a fleet of 40 Ford Focus cars powered by as much as 85% bioethanol made from locally grown grains.

When the BBC took a biofuel Focus around the Somerset countryside it felt no different from driving an ordinary model, though finding the fuel is pretty tricky. But this might gradually change.

From March this year half a dozen supermarket forecourts - in Taunton, Bridgwater, Bristol and Shepton Mallett - are preparing to supply the E85 biofuel under the Somerset Biofuel Project, an initiative which is seeking the "sustainable distribution of a locally grown, environmentally friendly fuel", according to Mr Hilton.

While this type of project is just the start, Mr Buchanan expects they will be "driving the sustainability agenda".

Environmentally friendly
Bioethanol made from grain produces 65% fewer greenhouse gases than petrol, according to the UK government agency Central Science Laboratory.

This is largely because the amount of carbon dioxide emitted during the production and consumption of ethanol is "almost equal to that removed from the atmosphere when crops for conversion are being grown", according to Saab Great Britain.

"One hectare of wheat produces about 29,000 miles of motoring, enough to take a car around the equator and still have 4,000 miles of fuel left," adds Green Spirit Fuels .

 "The oil companies and the big car companies will be driven down this road by the consumer," says Mr Buchanan.

Converted cars
To a limited extent, it is happening already. Some supermarket forecourts already mix ordinary petrol or diesel with biofuels, so that 5% of what drivers put in their tanks is bioethanol made from plants or trees.

And the practice is set to pick up pace after the government announced its Renewable Transport Fuel Obligation last autumn, which states that 5% of all motorcar fuel must come from renewable sources by 2010.

But in order to move beyond this 5% target, cars must go through a relatively cheap conversion that essentially involves replacing rubber seals and aluminium parts with materials that are not eroded by the bioethanol, explains Andy Taylor, Ford Europe's director of corporate citizenship.

Both Ford and Saab have unveiled bioethanol-enabled models for the UK market, which can run on pure petrol, or any mixture of petrol and bioethanol up to 85%, if E85 is not available. Saab says its E85-enabled 9-5 Biopower, which costs just £600 more than a standard 9-5, has the potential of reducing carbon dioxide emissions by 70% while at the same time improving the car's power.

E85's higher octane rating adds 30bhp to the 150bhp turbocharged engine, and a 15% gain in fuel efficiency can be had at high speeds, said Kjell ac Bergstrom, chief executive, of Saab Automobile Powertrain.

"Turbocharged engines are particularly well suited to the benefits of ethanol," Mr Bergstrom says.
 
Potential profits
Such confident swagger is turning heads in the world of finance, according to Graham Meeks of Climate Change Capital, a specialist merchant bank.

"We're seeing an enormous amount of interest from investors in this sector," he says. "The outlook is fairly positive," Mr Meeks insists - even though "there is some way to go in improving yields from crops", and despite bioethanol remaining a more expensive option than petrol due to "the cost of technology and the cost of feed stock".

In the near future, the biofuel industry can expect ever more support, both the government and from Brussels, as politicians look to both diversify fuel supply in order to improve fuel security, and to meet agreed reduction targets for carbon dioxide emissions, he predicts.

"There is the capacity to mobilise capital to build infrastructure to produce and distribute biofuels, and once you get the scale, the cost will come down," Mr Meeks says.