Click on a question below to reveal the answer. 

1. Why is the Carbon Capture and Storage (CCS) project in Longyearbyen so special?

   Longyearbyen offers unusual facilities that make the project unique: Longyearbyen has its own coal mine 12 km from town. All the power for lighting and heating consumed by the inhabitants is produced locally in a coal combustion power station; the community has a closed energy system. By capturing all flue gas and combustion products from the local power plant and by safely storing these wastes, the society of Longyearbyen will become the first CO2 free community in the world.
   
   Longyearbyen is of special interest as it is located in one of the best protected wilderness areas in the world, surrounded by huge areas of pristine landscape and untouched wildness. This unique landscape is valued by thousands of tourists and a high number of nobilities every year. With such an interest in Spitsbergen’s green profile, a CO2 free society will be a globally recognized show case.

2. What are the requirements in order to succeed with this project in Longyearbyen?

   There are two crucial success factors for the Longyearbyen CO2 project:

   There has to be a suitable storage site in the subsurface near Longyearbyen in which the CO2 can be stored. This site has to be more than 500 meters below the surface, since the increasing pressure with depth in the ground causes the CO2 to change from a huge volume of gas to a small volume of fluid at a given depth (pressure). The cold climate of Longyearbyen lowers the required pressure for this transition from gas to fluid, since this transition is affected by temperature.
   
   The CO2 emitted from the power station has to be captured.

3. Why do we think the rocks around Longyearbyen are suitable for CO2 storage?

   Rock succession: The rocks that we see in the mountain sides around Longyearbyen, and in drill cores of the subsurface of Longyearbyen, are made up of layers of sandstone and shale. Some 200-50 million years ago, the sandstones were deposited as beaches and wave-washed coastlines, whereas the shale was deposited as mud in deeper marine basins less affected by wave action.
   
   Reservoir: The sandstones hold porosity, which is filled with saline groundwater between the sand grains. This groundwater could be replaced by CO2, thereby filling the available space in the sandstone with CO2 by expelling the water.
   
   Top seal: The shale has very low porosity, and therefore acts as a sealing layer to groundwater flow. No water or other fluids can flow across the shale layers under normal conditions. Therefore, if we inject CO2 into sand-layers in the subsurface (reservoir) that has a roof of thick shale (cap rock), and this shale is sealing (top seal), we have a good storage site. The CO2 can not escape “up-section” from the reservoir sandstone.

4. Why can we store CO2 in the subsurface on Spitsbergen, but not on the Norwegian mainland?

   The exposed rock section of Spitsbergen, with its porous sedimentary rocks, is rather unique for Norway. Spitsbergen is part of the continental shelf around Norway, with its high number of sedimentary basins and hydrocarbon fields. On the contrary, mainland Norway is physical high above sea level, and has been deeply eroded over billion of years, representing the source of the sediments that has been washed out on the shelf.
   
   The deeply eroded Norwegian land mass today exposes rocks that have been deeply buried, metamorphosed, and later exhumed. This deep burial has removed all primary porosity in sedimentary rocks of this region that otherwise could have been of interest for CO2 storage.

5. Why is the cold climate of Svalbard an asset in storing CO2 as a fluid?

   In Longyearbyen we have one advantage with respect to the climate. As you noticed, Longyearbyen is a cold place with a frozen ground (permafrost). We therefore at the surface start with lower/colder temperatures than further south in Europe, which implies that we have to add less pressure to get the CO2 gas into fluid. For Longyearbyen, the required pressure converted to depth in the subsurface rocks (pressure caused by the load of rocks) is approximately 500 meters. In the North Sea, which is warmer, a similar depth would be more than 800 meters. We therefore in Longyearbyen have to use less energy to compress the CO2 into fluid; this is our geography related advantage.
   
   

6. Where will the CO2 that is required for the project come from?

   There are several sources to CO2 available, of which the most obvious is the local power station in Longyearbyen. The project aims on capturing this CO2. However, it is possible to transport small quantities of CO2 to Longyearbyen by ship, from mainland Norway in order to test the injectivity of the sandstone reservoir while the CO2 capture system is installed on the local power station.
   
   However it needs to be noted, the moment CO2 is captured from a CO2 emitting facility, such as the power station or LNG/liquid gas facility, the CO2 is regarded as industrial waste. The strict environmental laws of Svalbard forbid import of industrial waste.

7. How much CO2 comes out of a fairly modern, coal burning (combusting) power station?

   CO2 as it comes out of the pipe of the power station is a gas (vapor), commonly making up approximately 12-15% of the fumes. The rest is mostly vapor (water as gas).
   
   

8. How much CO2 is produced by the power station in Longyearbyen, and will all this CO2 be captured and stored?

   The power station in Longyearbyen emits around 80-85.000 tons of CO2 every year, with a CO2 concentration of 12-14% in the flue gas.
   
   The ultimate goal of the project is to capture as much as possible of the emitted CO2. The state-of-the-art capture technology will be able to handle c. 80-85% of the CO2 in the flue gas.

9. What happens when CO2 is captured from the power station?

   When we capture the CO2 from the gas of a coal combusting power station (post-combustion = after burning coal), the common technique is to use membranes that only CO2 can penetrate. With the help of such membranes we significantly increase the concentration of CO2, basically getting a clean CO2 gas on one side and a very small amount of CO2 and mostly vapor on the other side. The vapor mix is pushed out the pipe. For the clean CO2, we have to store it in the ground, where it should be captured for a very long time (the aim is commonly defined as 10.000 years for a permanent storage site).
   
   

10. Why is the volume of CO2 important and what happens if we cool down or pressurize the CO2?

    Since CO2 as a gas/vapor takes up much more space than CO2 as fluid/liquid or ice/solid, we have to treat the CO2 so that it changes into a smaller volume which is called a phase transition. The smaller volume is of course preferable in light of the space we would like to use in the ground for storage. This can be done by either cooling the CO2, or by pressurizing it, or a combination of both. Depending on how you combine pressure and temperature, the CO2 gas will change into ice or fluid.
    
    1) Example temperature: If we in a situation of atmospheric pressure (the pressure at the earth’s surface) cool down the CO2 gas, it will change into ice. This is so-called dry ice, which is use in many contexts. The most visual way can be exemplified by the plumes of smoke that for instance rock bands use in their shows. They use very cold CO2 ice that, when heated towards room temperature, converts back to CO2 gas; that gas is the big cloud (of CO2) that the rock band sends out in the air (adding more CO2 to the already dense air surrounding the sweaty audience). Returning to CO2 storage, the CO2 ice is not of much use, since it will not flow into a rock. We therefore aim for a CO2 fluid.
    
    2) Example pressure: If we increase the pressure of the CO2 gas at room temperature for instance to a pressure similar to 1000 m water depth (to 100 bars, from 1 bar at the surface), the CO2 change into a fluid. This fluid has flow properties quite similar to water, and therefore can be injected into a rock that allows for example flow of groundwater. This transition from gas to CO2 fluid reduces the volume of the CO2 gas 100 timer or more, to around 1%, in other words to a few drops at the bottom of a bucket that was full of gas.
    
    

11. What type of technology can be used to capture the CO2 from the Longyearbyen power station?

    The design of the power plant in Longyearbyen, with it’s coal combustion chambers and steam turbines, limits the options for CO2 capture. With this power system, the CO2 will have to be captured after the combustion of the coal, in a so-called “post-combustion process”.
    
    The post-combustion process strips the CO2 out of flue gas by the use of chemical membranes that allows CO2 to penetrate, but blocks other gases. The process is accelerated by heating.

12. How much will the different parts of the project cost, and who will pay these sums?
    
    
    The project has four phases, each with an estimated price: Identification of reservoir, to establish that a suitable rock is found in the subsurface near Longyearbyen: ~ USD 3 million
    
    Qualification of reservoir, to ascertain that it can receive the required amount of CO2: ~ USD 3 million
    
    Applying the reservoir by injection firstly water and secondly CO2 into the selected rocks, in a natural laboratory. This laboratory consists of one or more injection wells and a number of monitoring wells, and additional geophysical instruments, all aimed on following the CO2 plume in the sub-surface: ~ USD 2.5 million
    
    A full scale CCS operation, including CO2 capture on the Longyearbyen power station. The Capture system will have a price of ~ USD 100 million
    
    For the work related to establishing a CO2 injection laboratory, the project foresees continued collaboration with private companies and government funding institutions. The major expenses going into a CO2 capture facility must be seen in connection with the forthcoming upgrading of the power station in Longyearbyen, which is primarily a public concern.