Bubbling  through algal cultivation systems can greatly increase productivity and yield (up to a saturation point). Typically, about 1.8 tonnes of CO2| will be utilised per tonne of algal biomass (dry) produced, though this varies with algae species. The Glenturret Distillery in Perthshire percolate CO2| made during the whisky distillation through a microalgae bioreactor. Each tonne of microalgae absorbs two tonnes of . Scottish Bioenergy, who run the project, sell the microalgae as high value, protein-rich food for fisheries. In the future, they will use the algae residues to produce renewable energy through anaerobic digestion.