Fast growing cultured sea squirts can be used to produce biogas. The concept, which has been developed by IVL researcher Fredrik Norén, is being tested in a newly started research project that received 23 million in support from the Swedish Energy Agency and the EU.
The concept is based on an already established technique for growing mussels. Properly managed it is possible to get the fast growing sea squirts to grow on cultivation strips submerged in the sea. Sea squirts are, just as mussels, nourished by filtering large volumes of water from plankton and bacteria, which in turn allows for the nitrogen and phosphorus in the water to be taken up from the sea when the sea squirts are harvests. The growth rate is about two centimeters per month and therefore the sea squirts quickly create a significant biomass. After an anaerobic digestion step the biomass can be used as organic fertilizer.
The project is led by Marin Biogas and in partnership with, among others, the mussel farming company ScanFjord in Mollösund. During the three year project sea squirts will be cultivated, harvested and delivered to Eons digestion plant in Falkenberg. IVL Swedish Environmental Research Institute is responsible for the research and evaluation activities. One of the project goals is to see if the technique works in the Baltic Sea.
Biogas from cultured sea squirts