Friday, February 06, 2009

Yorkshire Carbon Capture Project gets Go-Ahead.

Mike O'Brien the British Minister for Energy has given consent to build a 900 MW power station at Hatfield in Yorkshire, which it is claimed developers are hoping to convert to carbon-capture technology "at a later date". This is a milestone on both fronts, since there is on the one hand a loud voice of objection from environmentalists who are against using coal because of its contribution to carbon emissions and secondly if carbon capture (CC) is added-on, that will be a first, and it is an "if". A new plant in Kent was approved a while ago, but without CC, on the grounds that the technology is unproven and expensive, so whether the Hatfield power plant is retro-fitted with CC remains to be seen.

Mr O'Brien is quoted as saying: “It is essential to replace older polluting power stations that are reaching the end of their lives with new stations that operate more efficiently."

What is clear is a shift of emphasis by the government, who while being aware of the anthropogenic carbon/greenhouse effect/global warming/climate change theories, are also well informed that the U.K. has an energy supply problem, to put it mildly. Hence avoiding people freezing in the winter and keeping the lights on in general here, is of more immediate concern than GW, the connection of which to wholesale climate change is a matter of model and debate. Thus, coal appears as a useful indigenous fuel, especially as we are running out of our other indigenous fuels - gas and oil, from North Sea fields that are likely to be almost dry in 6 years time.

How much accessible coal we have depends on how it is accounted, but there is enough for some decades in all likelihood, and much longer if underground coal gasification (UCG) is implemented on a grand scale. Uzbekistan has been running a UCG plant since the 1940's. Indeed, the National Coal Board ran an experimental UCG plant in Derbyshire in the 1950's but rejected the technology on the grounds it was too expensive compared to cheap solid coal that we were still producing to the tune of around 150 million tonnes/year.

The Hatfield plant is not a standard coal-fired power plant, which simply burns finely powdered coal, but rather uses coal that has been gasified, and it is the gas that is burned. It is termed a Combined Cycle plant and it was approved along with two more, one at Pembroke in South Wales (2 GW) and another at Kings Lynn in Norfolk (1 GW). Powerfuel, the company which bought the Hatfield colliery in 2006 plans to construct the "world's first large scale integrated gasification combined cycle (IGCC), near zero carbon emissions powers station with carbon capture capability." The grand total of 4 GW worth of electricity from the three new power stations is enough to power 4 million homes.

Their intention is to do this in two stages: first an 800 MW combined cycle gas turbine (CCGT) plant will be fabricated which burns coal that has been gasified into "syngas" (a mixture of CO + H2), and then this will be "upgraded" to an IGCC facility of 900 MW capacity running on coal from the Hatfield colliery. Richard Budge, CEO of Powerfuel, stressed the advantages of having a power producing facility in the north of England that runs on a secure fuel source based in the U.K. - i.e. coal. The first stage at Hatfield is expected to cost around £900 million and the second around £1 billion.

The initial CCGT station will employ gas turbines provided by General Electric, which are proven in their purpose, and it is planned that its construction will start in 2009 and finish in 2012, by when a connection to the national grid will have been implemented. The stage-two gasification technology is licensed from Shell and will capture 90% of the carbon emissions so that the fuel will be essentially hydrogen.

That carbon then has to be "removed for sequestration", i.e. put somewhere safe for hundreds to thousands of years, usually in rock-formations. Where, I wonder? Or, perhaps feed it to algae and turn it into liquid fuels? In that latter case, the carbon would end up in the atmosphere when the fuel was burned but it might be argued that there would be a trade-off against the oil that would otherwise be used as a fuel instead.

Related Reading.
[1] "Green Light for 900MW carbon capture coal plant in Yorkshire."
[2] "First 'clean coal' power station gets go-ahead," by Robin Pagnamenta:


Anonymous said...

If Powerfuel is serious about adding CCS as a future phase of the Hatfield IGCC project, the initial plant design should be "capture ready" in the strictest sense. This may have to be more than simply leaving space at the plant site for a so-called "bolt on Carbon Island" as GE has been promoting. (Gasification Technologies Council conference, Oct. 2008 )

The best way to assure "capture readiness" would be to include certain syngas process steps such as the water-gas shift in the original plant design. This may negatively impact performance of the plant before conversion to capture, but it will make the conversion itself less expensive and more practical.

When the shift process is included in the plant from the start, the syngas will be rich in CO2 and may not require injection of compressed nitrogen for control of NOx emissions.

Jacobs Consultancy (UK) has studied this subject and reported on it.

If the Hatfield IGCC plant does not include process functions that would simplify the conversion to CO2 capture, and assure that it will be practical and economical, one may question the seriousness of plans to retrofit for that purpose in the future.

Professor Chris Rhodes said...

I am also sceptical, as in the Kent plant which got the go-ahead without CC, on the grounds that the technology "was expensive and unproven".

I take your point about the CO + H2O --> CO2 + H2 shift being incorporated from the start.

I think the issue is to get something up and running as soon as possible although in fact it might be better to take longer but to install the fully integrated (IGCC)design from scratch. The first stage plant is cheaper and quicker to put-up and maybe it will stay in that form?


Chris Rhodes.

Thoughts said...

Carbon capture is a good idea if it works but its not the solution because even if we go down to a subsistence level of life we will find it hard to reverse global warming. See

Global warming and population

Professor Chris Rhodes said...

I suspect that carbon capture will not be adopted on the grand scale. I think that it is the running short of oil and gas that will be the leveller of humankind. The one way that carbon might be captured is through turning it into biochar and burying that in the soil, which would also improve fertility and crop yields... that said, the amount of engineering to do it to say, capture >7 billion tonnes of carbon a year (which is the amount we emit as a human species) would be vast. I have speculated that if it were done in small communities, then multiplying by the vast numbers of us there are on the Earth, it could ad-up to a lot!