Shooting for the Moon

26.06.2013
Carbon dioxide (CO2) must be captured and stored to keep the world from overheating. Work is now under way in western Norway to make this technology cheaper and more efficient.
  • Astri Sivertsen and Marit Hommedal (photos)

Vibeke Namstvedt

Testing.
Lab technician Vibeke Namstvedt analyses the amine solution from the plant.

 

The “launch pad” for a programme which has been called Norway’s own Moon landing project stands between the oil refinery and the combined heat and power (CHP) station at Mongstad north of Bergen.

“Catching our future” is painted in big, black letters on the administration block at the Technology Centre Mongstad (TCM), which currently embraces two different facilities.

One is based on a solution of amine and water, while the other uses refrigerated ammonia. Both capture carbon dioxide from flue gases released by the CHP station and the refinery cracker.

The ammonia plant was being converted during my visit, with only the amine facility operating. This was capturing 3.4 tonnes of carbon dioxide per hour from the CHP station, but has a top hourly capacity of 15 tonnes.

Both the facilities being tested can capture 80 000 tonnes per year, which means that the TCM currently ranks as the world’s largest demonstration unit for carbon capture.

At the moment, it is concentrating on post-combustion or flue-gas treatment technology. And both capture methods being tested are based on liquid absorption.

But TCM head Frank Ellingsen emphasises that there is no reason why other methods could not be tried out, and says space is available on the site for new test facilities.

TCM head Frank Ellingsen
< TCM head Frank Ellingsen


“Our strength is the availability of flue gases from two different sources,” he says. “We’re the front runner for testing and evaluating different technologies.”

Aker Clean Carbon has designed and built the amine plant, while Alstom is responsible for the ammonia unit. These two companies also own the respective test results.

In other words, the TCM’s role is not to develop technology, but to provide the opportunity for others to pursue such development.

“We conduct tests on behalf of society in cooperation with our owners,” explains Ellingsen.

The TCM is owned 75 per cent by the Norwegian government through its Gassnova company, with Statoil, Shell and South Africa’s Sasol chemical and energy group as partners.

They are not permitted to exploit test findings to develop their own technology, Ellingsen says. But they gain valuable experience by helping to build and run the capture facilities.

 

"For global temperatures to rise by no more than 2°C, 100 CCS plants must operational in 2020 and over 3 000 in 2050. Only eight are in place today."
(Source: IEA)



Discovery

Over the six months since it became operational, the TCM has already made an important discovery – amine concentrations released during the treatment process are so small that they have no negative consequences.

This finding has been documented in cooperation with several research institutions, and is useful because amine treatment is the most widespread method for carbon capture.

Fears that this chemical could damage health and the environment if released to the air have long been a “showstopper”, according to Ellingsen.

Mechanics inspect a column in the amine plant.
< Halfway to the Moon. Mechanics inspect a column in the amine plant.

 

Flue gases from the CHP station at Mongstad contain 3.5 per cent carbon dioxide, while those from the refinery hold 13 per cent – as much as a coal-fired power station.

So experience from the TCM will be transferrable to the most widespread source of electricity and pollution in the world.

Eight carbon capture and storage (CCS) facilities are currently in operation, including five in North America which all use the captured gas to improve oil field recovery.

Two of the remaining three are Norwegian and operated by Statoil, which has injected about a million tonnes of carbon dioxide below ground on Sleipner East every year since 1996.

This follows separation from natural gas on the North Sea field. Statoil has also stripped carbon dioxide from Snøhvit gas in the Barents Sea for injection since 2008.

And the company is involved with BP and Algerian state oil company Sonatrach in carbon storage on the In Salah gas and condensate field in the Sahara.

 

Lars Skov Olsen

Smoky job.
Lars Skov Olsen checks the refrigeration plant.

 

Recovery

Using carbon dioxide to improve oil recovery has been considered on several occasions in Norway, including for Grane, Statfjord, Oseberg East and Gullfaks.

But all these plans have fallen through because of insufficient carbon supplies and/or because they have been considered too expensive.

Economic assessments are also the reason why no new CCS facilities have been built over the past five years, and a number of planned projects have been put on ice or dropped for good.

Carbon capture is not regarded as particularly difficult. Various industries have used parts of the commonest capture and treatment technologies for many years.

But high costs represent a deterrent to adopting these methods unless the investment can be made to pay off through such means as improved oil recovery.

A capture facility installed at a coal-fired power station accounts for 80 per cent of the price tag for a complete CCS installation.

The investment drops by almost 50 per cent for a gas-fired power station, according to Australia’s Global CCS Institute in Canberra.

This organisation has also documented the obvious fact that power stations and industries with carbon emissions are cheaper without CCS than with – as long as emitting this greenhouse gas costs nothing.

The initial investment represents half the bill for a capture plant, with operation accounting for the rest, explains TCM technology head Olav Falk-Pedersen. So enhancing efficiency has much to offer.

He was involved a few years ago in investigating opportunities for introducing CCS at the Kårstø gas processing plant north of Stavanger.

The subsequent report from the Norwegian Water Resources and Energy Directorate (NVE) in 2006 illustrated the costs of adopting this technology.

“A modern gas-fired power station has an energy efficiency of about 59 per cent,” says Falk- Pedersen. “Adding CCS cuts this to 50-51 cent, including transport and storage.”

The TCM accordingly aims not only to identify the best solvents for absorbing carbon dioxide, but also to make the different capture facilities as efficient as possible.

If water and energy consumption could be reduced, power station efficiency would be increased to 52-53 per cent, says Falk-Pedersen.

“We’re working to fine-tune and optimise the treatment facilities,” he explains. “That’s why there’s so much metering equipment installed here at the TCM.”

A hundred samples are taken manually at the centre every day, with 4 000 measurements carried out using the computers which monitor the capture facilities.

The TCM also benefits from its proximity to the refinery in the form of access to experienced operators used to running process systems and able to advise on doing things better.

“Uncertainties always exist when scaling up from a small test plant to a full-scale installation,” observes Ellingsen. “We reduce that risk through the operational experience we acquire.”

 

Impossible

According to the International Energy Agency (IEA), it will be impossible to reach the target of limiting global warming to 2°C without large-scale adoption of CCS.

Along with enhancing energy efficiency and renewable energy, this technology is intended to cut global carbon emissions by 20 per cent up to 2050.

That means some 100 CCS plants must be operational by 2020, and over 3 000 by 2050. Otherwise it could cost 70 per cent more to achieve the reduction targets, the IEA warns.

Chief IEA economist Fatih Birol has also said that CCS will not be adopted without financial incentives to invest in it, and that carbon emissions must carry a cost.

This has so far not been the case, and low prices for carbon emission allowances have meant that interest in building CCS facilities has been poor.

“Climate challenges rather than economics are the driving force for adopting CCS,” observes Ellingsen.

Falling gas prices could mean that more power stations based on this fuel will be built. And the IEA’s desire for carbon emissions to cost money could soon be a reality.

That means it could pay to be prepared for CCS, and to be ready with solutions which have proved to work in practice.

 

Writing on the wall

Writing on the wall.
The global temperature cannot be kept down without CCS.