Vattenkraftverk som punktkälla av koldioxid till atmosfären : Test och utvärdering av en metod för mätningarav koldioxidavgång vid vattenkraftverk.

Sammanfattning

Climate change is a global problem that effects the entire world, and it is a big challenge for earth’s population to overcome. New techniques are going to be crucial to try and mitigate the effects from this climate changes. One such technique that’s already being used in industries that release a lot of CO2 is called carbon capture and storage (CCS) and this study is lookingat new areas to implement this technique in, more specifically if there is potential for CCS in hydropower since the powerplants can be considered a potential point source of CO2 to the atmosphere. The study has taken place at Kattstruppeforsen hydropower plant in Sweden, and it’s been carried out using Turner designs C-sense in situ pCO2 sensors measuring the concentration of CO2 upstream as well as downstream the powerplant. A mapping of spatial differences in the concentration downstream has also been carried out using the same type of instrument to ensure that themeasuring points are placed where they can have a good representation ofthe downstream concentration. The results from the mapping shows that there are no big differences when it comes to the concentration of CO2 at the different measuring points and the result from the upstream and downstream comparison showed that about 8% of the CO2 present in water upstream the powerplant was released when the water passed through the turbines because of degassing. The results from the mapping where positive for the method since it showed that the water was well mixed afterpassing the turbine and that our reference point was placed in a position that could represent the CO2 concentration downstream well which means that the method is good to carry on doing measurements. The result from the upstream and downstream comparison showed that CO2 was released from the water to the atmosphere during the whole period due to degassing at the turbines with an increase in for the last 3 days. This indicates that hydropower plants can be considered point sources of carbondioxide to the atmosphere. The main conclusion of this study is that the method works well to measure the degassing at the turbines.