Alfa Laval Nordic AS
Statoil and the Norwegian government are partners in a revolutionary CO2 capture project. The planned technology centre at Mongstad, north of Bergen, could pave the way for a dramatic reduction in worldwide CO2 emissions from fossil fuel fired power plants.
Clean energy could be one step closer to becoming reality. Global warming is firmly on the political agenda, with CO2 now widely acknowledged as a key factor. And power plants burning fossil fuels are subject to growing pressure as the major source of CO2 emissions worldwide.
Tore Torp, a pioneer of CO2 capture and coordinator of Statoil’s Europe-wide CO2 capture and storage research program at the Sleipner gas and oil field in the North Sea, says the project is an important step forward. “This technology is applicable to all types of fossil fuels and could have major environmental benefits,” he says, “but research is needed to reduce the costs and improve performance and reliability. The results will be highly significant for future capture plants.”
The project will create two pilot plants to test the most promising CO2 capture technologies at the new combined heat and power plant at the Mongstad complex, which also comprises an oil refinery, fractionation plant and crude oil terminal. The power plant is fuelled by both natural gas and refinery gas. Statoil and government-owned Gassnova have also committed to building a full-scale plant based on the technology that proves most successful.
The approaches to be tested are based on absorption of CO2 in either amine or chilled ammonia. The technology centre will verify their relative effectiveness, and assess which gives the best overall economy – a critical factor. Both have been used commercially in removing CO2 from natural gas, but this is the first application with purely environmental motives. Aker ASA and Alstom Power have been contracted to build the pilot plants, which will use amine and chilled ammonia respectively.
The biggest challenges are economic rather than technical, Tore Torp says. “Energy consumption is the toughest issue. “This accounts for 70-80 percent of the cost of capture; the chemical reaction in the absorption process is strong, so a lot of energy is required to strip the CO2 afterwards. Absorption is most effective at low temperatures and separation at high temperatures, so the circulating absorption medium must be repeatedly cooled and heated. Heat exchangers are therefore a critical part of the process.” Mongstad Technology Center is a result of the escalating debate around global warming” says Hans-Jacob Svensen, Segment Manager, Energy & Environment, Alfa Laval Nordic. It is also an excellent example of how Statoil and Alfa Laval can obtain mutual benefits through the current frame agreement on heat exchangers – by enabling Alfa Laval to gain experience and to develop new products to meet the demands of the future.
Safe storage of the stripped CO2 is another important area for developing a widespread market for the technology, and continues to be researched at Sleipner. “More than 11 million tonnes of CO2 have so far been injected into an aquifer more than 800 metres below the seabed, and successfully contained,” Torp says. Other challenges for the Mongstad project include the difference in CO2 concentrations between natural gas and power plant flue gases (exhaust gases that leave through the chimney), as well as scaling up from pilot to full-scale operation. “The performance of the heat exchangers will also be even more critical due to the high temperature of the flue gases,” Torp says. The pilot plants are expected to be completed in 2011, and operative in 2012. The Norwegian government will make a final decision on the full-scale plant when the test results are clear.