When a group of Greenpeace activists sneaked over the fence and into
Kingsnorth power station in Kent last October it seemed like just another
protest. A few days of publicity, then quickly forgotten.
After entering the building beneath the plant’s giant chimney, they padlocked
the door and began the nine-hour job of hauling themselves and their
rucksacks up the internal ladders that led to the top of the stack. Soon the
nation’s media were relaying the bizarre sight of red-clad demonstrators
waving from the top of a power station chimney and listening to Will Rose,
one of the protesters, explaining what it was all about.
“Kingsnorth emits 20,000 tonnes of CO2 every day - the same amount as the 30
least polluting countries in the world combined - and now the government
wants to build a new coal-fired power station right next to it,” said Rose.
“We want to stop them. Coal is changing the world’s climate.”
This month, he was one of six people cleared at Maidstone Crown Court of
causing criminal damage at the Kent plant, after arguing that they were
acting lawfully to try to stop damage to properties around the world being
caused by global warming.
Rose comes from a family that has lived off coal for generations. His father,
grandfather and great-grandfather were Northumberland miners so he knows how
coal was once the bedrock of many communities. Back then nobody knew about
climate change and the connection with CO2, but the science showing that
connection is making coal the centre of controversy. This invisible and
odourless gas alters the atmosphere so that it retains extra heat - and coal
gives off more of it than any other major fuel.
Emissions from coal-fired power stations are estimated to be 830g of CO2 per
kilowatt hour of power generated - compared with 380g for gas and 22g for
nuclear power. One plant alone, Drax in West Yorkshire, emits 21m tonnes of
a year, making it Britain’s biggest emitter. Nowadays more than half ofCO2
Britain’s coal is imported from Siberia but it remains among the cheapest
ways of generating power, so places like Drax will stay in business. What
the coal industry is hoping for is that scientists and engineers will find a
way of cut. ting out the CO2 The Kingsnorth acquittals pushed such ideas to
the top of the political agenda. Last week the Environment Agency intervened
in the debate by making clear its belief that coal-fired power stations must
not be built unless they can capture and store CO2. It warned that
government approval for plants such as that proposed at Kingsnorth could
“lock” the UK into high-carbon technologies.
However, Mike Farley of Doosan Babcock, one of Britain’s largest engineering
firms, believes this can only be achieved in stages, the first of which is
to make coal-fired power stations much more efficient, to be followed by
removing the CO2 altogether. “Britain needs coal because we should get our
energy from a mixture of fuels and because we have hundreds of years of coal
in our mines,” he says. “That gives us security, especially at a time when
North Sea gas and oil are declining and we face having to import 80% of our
needs by 2020.”
Most existing coal-fired power stations convert only about a third of the heat
they generate into power, with the rest wasted. Farley believes that
so-called supercritical stations, using higher temperatures and pressures,
could achieve efficiencies of up to 60%, mean-per unit of power generated.
In the long term, say the engineers, coaling less CO2 can be made into a
zero-emission fuel using a technology known as carbon sequestration, where
the gas is separated and then buried for ever, for example by being pumped
into rock strata.
Some countries have already decided this could be the technology that makes
coal a green fuel. This month, at a coal-fired power station in Germany,
work began on the world’s first complete demonstration of carbon capture and
storage (CCS). Built alongside the 1,600mw Schwarze Pumpe power plant, the
£56m project will capture up to 100,000 tonnes of CO2 a year and compress
it. Then it will be transported 100 miles to the depleted Altmark gas field
for burial more than a mile underground.
The scheme will use an oxyfuel boiler, one of the three main types of CCS
technology. This involves burning coal in pure oxygen, producing a waste gas
. The other CCS methods that is pure CO2 are precombustion, where coal is
burnt in a controlled atmosphere to generate hydrogen and CO2, and
postcombustion, which scrubs the exhaust gases from a power station.
The Mountaineer scheme in West Virginia, America, should be the first of the
global pilot plants to put together all the pieces of postcombustion CCS
technology. It is the prototype for a much bigger plant that would capture
and store emissions from a coal-fired power station in Oklahoma. If
approved, it would start work in about four years, trapping and burying 1.5m
tonnes of annually in a nearby oilfield. CO2 In Europe there are plans for
12 more demonstration plants but they are moving slowly, especially in
Britain. In 2006 the government announced a competition for the construction
of a 400mw demonstration project to start in 2014. Since then, it has made
little progress beyond ruling out half the companies that wanted to tender
by restricting bids to postcombustion technologies. A decision is expected
next year – meaning the technology is unlikely to have been sufficiently
tried and tested to be fitted to power stations before 2020.
Jeff Chapman, chief executive of the Carbon Capture and Sequestration
Association, which has more than 60 member companies, says that with 74m
added to the global atmos-tonnes of CO2 phere from fossil fuels each day, it
is essential to avoid delays: “The world is going to keep on burning coal in
ever greater amounts so we need to make it a clean fuel. Britain alone is
planning several new coal-fired power stations.”
A study by the Intergovernmental Panel on Climate Change into CCS found that
the technology would work best on large sources of CO2 such as power
stations and cement works – of which there are about 8,000 worldwide.
Collectively these produce about 14 billion tonnes of CO2 a year – a big
chunk of the 27 billion tonnes humanity generates from burning fossil fuels
each year.
For Britain’s power companies, however, there is little chance that the
prospect of such technologies will persuade Greenpeace to lay off them. Jim
Foot-ner, the group’s spokesman on coal, says that although he welcomes the
research it will be years and probably decades before it can be applied on a
large scale. “The problem of CCS is that it is an unproven technology that
may work in the future, but which is being used to justify building
coal-fired power stations now.”
Engineering a cleaner future
Wasim Oulabi is convinced coal is the right choice for the next generation of
power stations. He joined Doosan Babcock, an energy services company, two
years ago after completing his masters in chemical engineering at Surrey
University and is working towards his engineering chartership.
Oulabi, 28,above, now works in emissions control, part of the process
engineering department at Crawley, West Sussex, helping to design coal-fired
boilers for new power stations and retrofit older ones with systems to
reduce nitrogen and sulphur oxides.
The department is installing selective catalytic reactors (SCRs) in several
working power stations. These remove nitrogen oxides, produced during
combustion at high temperatures, which can cause acid rain. The process can
cut harmful emissions by half. New power plants are also being fitted with
technology that involves restricting and releasing air into the furnace at
different stages of combustion to ensure a cleaner burn.
“I believe coal is an upcoming market,” says Oulabi, who helps design the
SCRs. “Most of the coal we use comes from Australia, Indonesia and South
Africa. These are stable countries, the supply chain is good and there is a
possibility of using British coal in future.”
Oulabi is confident that coal can be made into an acceptable green fuel.
“Technology has advanced a lot since the 1970s and ’80s, so we can get
cleaner power by removing all emissions and making more efficient boilers.
There is technology to remove the nasty bits like sulphur dioxide, nitrogen
oxide, particulates and ash. A lot of power stations that are being vilified
have installed this technology. We are also working on carbon capture and
storage, and flue gas desulphurisation, so in that sense coal is getting
cleaner."
During training, Oulabi spent four months at the company’s Renfrew plant
outside Glasgow, working with fluid dynamics software. “The chemical
engineering in the work I’m doing incorporates the subjects I liked at
university,” he says. “For the future, management is always tempting but I’m
enjoying the engineering side.
“The starting salary compared with other jobs was pretty impressive. I was
very happy with what I had and that has increased by about 20%. I want to
stay with coal and the company. There is a market and hopefully there will
be a lot of work in the future.”
