Greek shipping company Enesel has installed several LFC biodigesters, produced by Power Knot Ocean, across its fleet to convert food waste into environmentally benign graywater.
The LFC biodigester digests most food waste in 24 hours, using microorganisms and enzymes. The company said the resulting greywater is environmentally safe to discharge into the ocean.
Food waste is a perennial problem for both commercial ships and cruises. According to MARPOL Annex V, food waste should be discharged more than 12 nautical miles from shore unless the food has been ground up. If it is ground up it can be deposited three nautical miles from shore except in protected areas.
A recent study shows that ship-generated nutrient-rich food waste contributes to excessive plant and algal growth and reduced oxygen in marine ecosystems and can exacerbate climate change impacts.
Power Knot Ocean has nine different sizes that digest from 10kg (20lb) per day to 6000 kg (13200lb) per day of food waste.