Sunday 27 September 2009

Secrets of the black lagoons

There could be money in the ash that pours from power stations

Not far from the Fiddler’s Ferry power station in Cheshire, four lagoons of fetid, black liquid lie eerily still. They are not nature’s work.
More than 15m tonnes of ash lie in the watery dumps, the byproduct of nearly four decades of coal incinerated in the plant’s furnaces.
Amid the controversy over cutting carbon emissions from the dirty business of producing power, the process’s other main waste product has largely been forgotten.
Each year about 6m tonnes of ash is produced by Britain’s power stations. Half is used as low-grade filler in construction materials such as asphalt and breezeblocks, but the rest is dumped in landfill or stored in lagoons such as those at Fiddler’s Ferry, near Warrington.
Philip Michael, 62, spent his career in the mining and power industry and always felt that it could be converted into something useful — and profitable. Nine years after co-founding a company to utilise the waste, he looks to have achieved that goal.
Rocktron, his Bristol-based firm, has developed a plant adjacent to Fiddler’s Ferry that makes the sludge and fresh ash into high-tech additives for use in water filters, car components and ultra-lightweight paint for aircraft. Scottish and Southern Energy, which owns Fiddler’s Ferry, put up £30m to finance the plant.
John Watt, 74, a geophysicist and co-founder of Rocktron, is in talks with firms in China, India and America about building similar plants. “Nobody has ever done this before. It is a world first,” he said. “We have applied a mining industry solution to a global environmental problem.” Rocktron has patents for a process that takes dirty ash through a series of steps using reagents, centrifugal force and water separation to break it into five constituent parts. The most useful is microscopic glass beads, which are sifted out through pores as small as 1,000th of a millimetre wide. Once stripped of surface impurities such as salts, they can be used in complex plastic components and paints.
Companies including Ford are interested because of the potential to cut the weight of vehicles and thus increase fuel efficiency.
The pure carbon found in the ash can be used in water filters, while magnetically charged particles can help to shield complex electronics from electromagnetic interference. Larger glass spheres can be used as fillers for cement. “Nothing is wasted,” Michael said.
He began developing the reactive agents to sift out carbon and other usable materials from ash more than 20 years ago while working at a power station in Berlin. Back in the UK in the 1990s, he mortgaged his house to build a demonstration plant. It worked but he could not get the Central Electricity Generating Board to back a larger plant.
His work dovetailed with that of Watt, a geo-physicist who had been developing the higher end additives from ash.
The two met in 1998 and founded Rocktron two years later but were turned down by 53 banks — not that they’re counting — before Scottish and Southern Energy offered support in 2007.
“You can imagine the despair at times. Ten years is a long time to be living off the Salvation Army,” Watt joked.
Watt estimates that there is more than 100m tonnes of ash in landfill and lagoons in the UK alone.