Carbon capture and storage technology

The world's first complete demonstration of carbon capture and storage (CCS) technology will begin next week at a coal-fired power station in Germany.

Built alongside the 1,600MW Schwarze Pumpe power plant in north Germany, the demonstration experiment will capture up to 100,000 tonnes of CO2 a year, compress it and bury it 3,000m below the surface of the depleted Altmark gas field, about 200km from the site.

The €70m (£57m) project has an output of around 12MW of electricity and 30MW of thermal power, enough for more about 1,000 homes.

The pilot plant will use an oxyfuel boiler, one of three types of CCS technology. This involves burning coal in an atmosphere of pure oxygen – the resulting waste gas is almost pure CO2 and this can be buried, preventing it from entering the atmosphere and contributing to global warming. The other CCS methods are pre-combustion, involving the removal of CO2 before burning by pre-treating the coal, and post-combustion, which scrubs the exhaust gases from a power station.

"It's a very important and tangible step forward," said Stuart Haszeldine, a geologist and CCS expert at the University of Edinburgh. "It is the first full-chain demonstration of oxyfuel as a carbon capture technology. It connects all that for the first time in a working system." He added the Schwarze Pumpe pilot "shows what can be done if the state and company are aligned and have confidence in each other".

CCS is seen as a potential solution to the projected increased use of coal in power stations around the world. At its best, it would trap up to 90% of a plant's carbon emissions and, though each element of the capture, transportation and storage process is already proven and in use, until now no one had demonstrated a full-cycle system, even at the small scale of a pilot.

A full-scale system remains years away, largely because developing such a system is likely to be very expensive. As a result, many leading power companies have been reluctant to fund CCS individually, arguing that governments should also shoulder some of the financial risks.

"Coal, which represents 40-50% of electricity [generation], is necessary and will continue to be necessary because of fuel safety and accessibility. It is one of the most shared resources around the world," said Philippe Joubert, chief executive of Alstom, the company that built the specially equipped oxyfuel boiler for the Schwarze Pumpe's Swedish owners, Vatenfall.

He said Alstom's research is aimed at keeping the world's options open on how electricity is generated in the coming decades. "Coal has to be used but it has to be clean."

Source: Guardian.