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US 6,368,849 B1Granted
Method and plant for the treatment of liquid organic waste
AssigneeBioscan A/S
InventorBirgir Norddahl
Life of this patent
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AssigneeBioscan A/S
InventorBirgir Norddahl
Estimating the term…
A method and plant for the treatment of an organic waste material in liquid form, e.g. liquid manure from livestock, the method comprising filtering fibres and particles from the liquid, subjecting the liquid to anaerobic fermentation in a biogas reactor, separating a substantially sterile and particle-free permeate stream from the biogas reactor, e.g. using ultrafiltration, subjecting the permeate stream to treatment with an ammonia stripper at an elevated temperature and preferably at reduced pressure to remove substantially all ammonia and carbon dioxide and to result in an ammonia fraction and a nutrient salt fraction, and separating the nutrient salt fraction into a fertiliser concentrate fraction and a water fraction, e.g. using reverse osmosis. The end products of the method are clean water, ammonia concentrate, fertiliser concentrate containing salts of P and K, compost and high-quality biogas with a high methane content.
A method for the treatment of an organic waste material in liquid form, comprising:
A plant for treatment of an organic waste material in liquid form, comprising:
A method for producing biogas enriched in methane, the method comprising subjecting an organic waste material in liquid form to anaerobic fermentation in a biogas reactor, wherein liquid from the biogas reactor is subjected to ultrafiltration performed by using a tubular ultrafiltration membrane having a mean molecular weight cut-off of up to about 100,000 Dalton, wherein the separation is performed at a pressure of about 4-6 bar to result in a permeate fraction enriched in carbon dioxide and a methane-enriched fraction, said methane-enriched fraction being returned to the biogas reactor to result in biogas having a methane content of at least about 70% by weight.
Dependencies are inferred from the claim text.