The Norwegians are taking climate change seriously. The Scandinavian country has already set itself ambitious climate mitigation goals, and is now aiming to become a pioneer in the area of Carbon Capture and Storage (CCS). “CCS is an important element of our climate policy and the government intends to realise at least one demo project,” explains Terje Søviknes, the Norwegian Oil and Energy Minister in a press release from Gassnova, Norway’s state company for CCS. The project is set to cover the entire process chain – from CO2 separation and storage through transport to underground sequestration of the gas.
Feasibility study identifies three candidates
“Norway’s initiative is a hugely important step for advancing the technology and bringing it to widespread industrial deployment,” comments Olaf Christoph, Business Development and Sales Manager for Hydrogen and Synthesis Gas Plants at Linde Engineering in Dresden. “In 2016, Gassnova undertook a comprehensive feasibility study to identify potential candidates that emit serious volumes of CO2,” Christoph outlines. Mid-April 2017, the study short-listed the following three companies: the Norcem cement factory, the energy recovery plant in Klemetsrud and the Yara ammonia factory in Porsgrunn.
Linde is engaged in cooperation talks
The industrial enterprises will now receive Norwegian government funding to the tune of 360 million Norwegian krone – equivalent to almost 40 million euro – to continue their current studies on CO2 separation. Gassnova intends to green-light at least one project. Linde Engineering Dresden has been selected as cooperation partner for the entire CCS integration process at ammonia producer Yara,. Christoph explains why: “We have established massive know-how in this area and have several reference projects that underscore our technical expertise and reach. Especially important is the fact that we offer the entire chain – extending from designing the carbon capture plant through purification and liquefaction of the separated gas to the final storage stage.”
CCS project references
The cooperation with Yara represents a massive undertaking in terms of the volumes of CO2 emitted. Each year, the ammonia plant emits up to 805,000 tonnes of this greenhouse gas, or almost 2,400 tonnes per day, and this has to be captured and treated. “Very few references are available anywhere in the world for a task of this scale,” Christoph admits. “Linde can refer to two plants that have already been successfully delivered. In Hammerfest, we capture 2,000 tonnes of CO2 from natural gas every day, and in Al Jubail, we purify and liquefy around 1,350 tonnes of carbon dioxide per day.” The RWE power plant in Niederaussem, Germany, and the Southern Company National Carbon Capture Center in Wilsonville, USA, are two additional reference projects for Linde’s CCS technology. In addition, the operating costs of the Linde plants are comparatively low.
CAD drawing of carbon dioxide purification and liquefaction plant as delivered by Linde to its customer UNITED in Al Jubail, Saudi Arabia.
Carbon dioxide capture, purification and liquefaction
“Carbon capture can make a valuable contribution to the reduction of industrial emissions. As such, we are pleased with this unique opportunity to cooperate in the development of a demo plant,” Petter Østbø commented, Yara’s Executive Vice President Production in a press release issued by Gassnova. The ammonia factory has two CO2 sources ready to be retrofitted with Linde’s post-combustion capture technology and the synthesis gas scrubbing technology: The post-combustion capture technology fits the steam methane reformer and the synthesis gas scrubbing technology fits the ammonia process. The post-combustion capture process involves multiple steps to separate the carbon dioxide. An absorber is installed at the core of the plant in the countercurrent flow, where the hot flue gas comes into contact with a scrubbing liquid – an organic solvent from the chemicals group BASF, which absorbs carbon dioxide from the off-gas.
CO₂ scrubbing for flue gas
“Two very different flue gas streams are emitted at Yara,” explains Linde expert Christoph. “At the steam methane reformer, the off-gas to be treated has atmospheric pressure with a high oxygen content. Meanwhile, the synthesis gas at the ammonia plant is emitted at a pressure of 26 bar and doesn’t contain oxygen. That is why we are employing two different BASF scrubbing agents from the OASE® brand.” The CO2-saturated scrubbing liquid is routed to a desorber where it is heated. This process removes the CO2 from the liquid again. The liquid is then cooled and pumped back to the absorber, where the scrubbing cycle begins again.
Transport by ship from the Norwegian coast
The processe of liquefying and storing the separated carbon dioxide, which leaves the post-combustion plant at a minimum purity of 99.9 percent by volume, will also rely on technologies from Linde. The engineering experts will be responsible for providing large-volume tanks to store carbon dioxide at a pressure of 16 bar and temperatures as low as minus 30 degrees Celsius. “For the Yara project, we have to plan storage capacities of up to 12,000 tonnes,” Christoph reveals. The infrastructure and technology set-up at Yara provides ideal conditions for Linde. For one thing, the plant’s location in an industrial park provides easy access to heating and cooling water, and it has the further advantage of being situated on a fjord. This allows for convenient shipping of the liquefied greenhouse gas by tanker. Finally, the CO2 is destined to be injected deep under the seabed in the North Sea by pipeline. The Smeaheia area, located east of the Troll natural gas field, has already been chosen as a secure sequestration location.
Industrial plant of ammonia producer Yara in Porsgrunn, Norway.
The CCS countdown is running
All three selected candidates are currently working on a further concept study to be submitted to Gassnova. The Norwegian government will announce at the start of 2019 which projects will be selected. If everything goes well, operations will start in 2022.This will be an important milestone for industrial-scale use of the CCS technology.