Abstract

Disclosed is a method for reducing methane emission from slurry produced in a livestock farm. The method comprising the steps of guiding unheated slurry from the livestock farm to a slurry heat exchanger, raising the temperature of the unheated slurry in the slurry heat exchanger to at least 65# Celsius, guiding the at least 65# Celsius hot slurry to an intermediate slurry tank, raising the temperature of the heated slurry to at least 75# Celsius in the intermediate slurry tank, guiding the at least 75# Celsius hot slurry through the slurry heat exchanger to exchange heat with the unheated slurry to raise the temperature of the unheated slurry to the at least 65# Celsius and to cool the at least 75# Celsius hot slurry to at least below 40# Celsius, and guiding the at least below 40# Celsius cold slurry to a slurry reservoir. Furthermore, a slurry treatment plant for reducing methane emission from slurry is disclosed.

IPC Classes  ?

• C05F 3/06 - Apparatus for their manufacture
• C02F 11/18 - Treatment of sludge; Devices therefor by thermal conditioning
• C05F 17/957 - Apparatus therefor using two or more serially arranged devices
• C05F 17/40 - Treatment of liquids or slurries
• C05F 17/986 - Constructional parts, e.g. floors, covers or doors for feeding or discharging other material the other material being liquid
• A01C 3/02 - Storage places for manure, e.g. cisterns for liquid manure; Installations for fermenting manure
• C05F 17/60 - Heating or cooling during the treatment
• C05F 17/80 - Separation, elimination or disposal of harmful substances during the treatment

Abstract

Disclosed is a method for reducing methane emission from slurry (2) produced in a livestock farm (1). The method comprises the steps of guiding the slurry (2) from the livestock farm (1) to a dewatering unit (12) in which the slurry (2) is at least partially dewatered by extracting a watery fraction of said slurry (13), guiding the slurry from the dewatering unit (12) to a steam dryer (3), drying the slurry in the steam dryer (3), guiding the dried slurry (4) into a pyrolysis reactor (5) to produce pyrolysis gas (6) and biochar (7) through a pyrolysis process in the pyrolysis reactor (5), guiding at least a portion of the pyrolysis gas (6) to a combustion unit (8) in which the pyrolysis gas portion is combusted to raise the temperature of the combusted pyrolysis gas (9), guiding the combusted pyrolysis gas (9) to the pyrolysis reactor (5) to drive the pyrolysis process, guiding the combusted pyrolysis gas (9) from the pyrolysis reactor (5) to the steam dryer (3) to increase the temperature of steam (10) in the steam dryer (3), and heating the watery fraction of the slurry 13 to a temperature at least above 75° Celsius by means of the steam (10) from said steam dryer (3). Furthermore, a slurry treatment plant (20) for reducing methane emission from slurry (2) is disclosed.

IPC Classes  ?

• C02F 11/10 - Treatment of sludge; Devices therefor by pyrolysis
• C02F 11/13 - Treatment of sludge; Devices therefor by de-watering, drying or thickening by heating
• C05F 3/00 - Fertilisers from human or animal excrements, e.g. manure