Here a coal train.jpg

is shown leaving Hatfield Colliery in Yorkshire, U.K. Plans are in hand to build a 900 MW power station on the site using syngas from coal to drive gas and steam turbines, along with a carbon capture system.

Power plant design intended to produce electricity while effectively handling CO2

The soaring cost and availability of oil-based fuels has focused attention on other fuel sources. Consequently, there are currently huge investments in renewables like wind power and biofuels. However, these will not meet more than a fraction of most countries’ requirements and are, in any case, highly controversial. The one fuel that is in abundance worldwide is coal, and energy-hungry nations like China and India are investing heavily in coal-fired power stations. The effect of this has been to push coal costs up sharply. At the time of writing, Australian coal prices have increased by three times in one step.

In the United Kingdom, a firm decision has been taken by the government to renew its investment in nuclear power. But this is a long-term solution. A shorterterm approach is to take advantage of Britain’s extensive coal stocks. It is estimated that these are sufficient, at present consumption rates, for hundreds of years.

However, a decision to go for coal is also highly controversial mainly because of the pollution problem.In these circumstances, a scheme under way in northern England looks like a promising approach. The plan is to build a power station alongside one of the largest privately owned collieries still in operation and generate power using carbon capture technology.

Powerfuel Power Ltd., a U.K.-based independent power producer, has planned a 900 MW integrated gasification combined-cycle (IGCC) power plant at Hatfield Colliery in South Yorkshire, England. The plant will use technology from GE Energy and a letter of intent has been signed by both companies for GE to supply steam and gas turbines for the power station. Both companies point out that the planned technology provides critical fuel flexibility to support cleaner power plants.

Powerfuel Power has signed a connection agreement with the U.K. National Grid. The Hatfield Colliery has been brought back to life by its owner, Richard Budge,at a cost of some US$180 million. “Most people think it is unbelievable to reopen an old colliery, but we have done it,”said Budge. “I always thought there was a future for coal, but many others didn’t.The rest of the world has been investing in coal mining since we started to close ours down.

Budge said that when it becomes fully operational, Hatfield will produce between 2 and 2.5 million tonnes of coal a year — enough to supply power for two of Britain’s biggest nearby cities,Leeds and Sheffield.The gas turbines will be fired by gas derived from coal using Shell’s coal gasification process. The process was developed by the oil company in 1956 and comprises a “dry feed” technique that partially combusts the coal in oxygen to produce a “syngas” rich in hydrogen and carbon monoxide, containing about 80% of the coal’s original calorific value.

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system for producing syngas from coal. The syngas would be used to fuel the GE F-Class gas turbines.

around 15% of the pressurized steam from the gasification process is recovered to drive the steam turbines,while the hydrogen in the syngas is used to fuel the gas turbines. The process facilitates the separation of CO2 pre-combustion in the turbine generators.The process has been licensed extensively around the world. The power plant is scheduled to start operating at the end of 2011 and will be converted to syngas in 2013, thus allowing for a phased installation of the combined-cycle gas turbine plant and the so-called gasification island.

“With the selection of the GE combined-cycle gas turbine technology, we will have the fuel flexibility to respond to policy changes and decisions to have this plant available for carbon capture and storage as early as 2013 and support an early implementation of clean coal generation in the U.K.,” said Budge.“Our objective has always been to build a ‘near-zero emissions’ power plant next to Hatfield Colliery, and GE technology is the best choice to enable that.”

Commenting on behalf of GE Energy,European region president, Ricardo Cordoba, said, “We welcome the selection of our highly flexible gas turbine technology and are looking forward to supporting Powerfuel’s milestone as they become the first power company in Europe to use cleaner coal technology commercially to generate electricity. GE’s technology is well positioned to support this cutting-edge project, which will help to provide a path forward for cleaner coal technology and wider commercial use.”Cordoba pointed out that in Europe,GE Energy has its own European Cleaner Coal center of excellence. The center is located in Warsaw and underscores the company’s commitment to IGCC along with carbon capture and storage (CCS) technology.

Peter de Witt, executive vice president,global businesses of Shell Gas & Power, said that Shell is at the forefront of developments in clean coal — the agreement with Powerfuel is the second the company has signed in Europe in less than a year. It is the first in this region to incorporate carbon capture and storage from the outset. The deal signals a further expansion of Shell’s lean coal business outside China,where it has sold 15 gasification licenses in the past five years. The combined-cycle system,in which the normally wasted exhaust from gas turbines is boosted through boilers and used to drive steam turbines, is well-accepted technology in the power generation industry and is a valuable way of boosting overall thermal efficiency.

GE’s F-class gas turbines were introduced to the market in 1987 just when the use of natural gas for power generation was becoming fashionable, and now GE claims over 20 million hours of commercial operation in the field. The company shipped its 1000th F-class machine last year, and GE said they were the first gas turbines in their class to reach 40% turndown while maintaining single-digit NOx and CO emissions.

GE said the gas turbines that will be used at Hatfield will be supplied with different combustion systems to run on a variety of fuels, including the high hydrogen content gas, which will be available at Hatfield. GE said only small modifications to the hot gas path are required to allow for utilization of high mass-flow syngas fuels.

The progress in the development of the F-class machine was demonstrated in 2007 when the first dual-fuel versions of the newest addition to the family, the Frame 9FB, were used at the Iberdrola power station of Escombreras in Spain (see D&GTW, October 2007). Powerfuel has yet to agree to a partner for the CO2 storage technology or identify a potential storage site. The plan would be to pipe the CO2 to a storage site in the North Sea. Carbon capture technology is, as yet, in an early stage.

one of the first large-scale examples in the field is the Schwarze Pumpe coalfired 1600 MW power station in the former East Germany where the scheme will dispose of 100 000 tonnes of CO2 a year and bury it 3000 m under a nearby gas field. Several power stations in the U.K. are also reviewing the possibility of using carbon capture technology.

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of a carbon capture system used on a power plant that can aid in oil recovery operations.

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