Nutrient recovery systems and methods
AssigneesDVO, Inc., Washington State University, Andgar Corporation
InventorsQuanbao Zhao, Stephen W. Dvorak, Shulin Chen, Craig Frear, Bryan J. VanLoo
Life of this patent
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Abstract
Methods, systems, and apparatuses for anaerobic digestion of waste fibrous material and the recovery of nutrients are provided. Methods, systems, and apparatuses disclosed herein provide mechanisms to release dissolved gases from anaerobic digester effluent. Methods, systems and apparatuses disclosed herein can recover one or more nutrients from anaerobic digested effluent using a range of temperatures, aeration rates, aeration times, pH ranges, and settling times.
Claims12
A method for recovering a nutrient comprising:
- (a) heating and aerating anaerobic digester effluent in an aeration reactor for a time period ranging from 12 hours to 36 hours to convert soluble ammonium to gaseous ammonia;
- (b) providing gaseous ammonia from the aeration reactor to a stripping tower, said stripping tower providing controlled amounts of acid that reacts with gaseous ammonia;
- and
- (c) recovering an ammonium salt produced from reacting the acid with gaseous ammonia in the stripping tower.
A method for recovering a nutrient comprising:
- (a) heating anaerobic digester effluent containing fibrous solids and suspended solids to about 160° F.;
- (b) separating fibrous solids from the suspended solids in the effluent;
- (c) heating and aerating the effluent in an aeration reactor for a time period ranging from 12 hours to 36 hours to convert soluble ammonium to gaseous ammonia;
- (d) providing gaseous ammonia from the aeration reactor to a stripping tower, said stripping tower providing controlled amounts of acid to react with gaseous ammonia;
- and
- (e) recovering an ammonium salt produced from reacting the acid with gaseous ammonia in the stripping tower.
A method for recovering a nutrient comprising:
- (a) heating and aerating anaerobic digester effluent in an aeration reactor to convert soluble ammonium to gaseous ammonia;
- (b) providing gaseous ammonia from the aeration reactor to a first stripping tower, said stripping tower providing controlled amounts of acid that reacts with gaseous ammonia;
- (c) providing unreacted gaseous ammonia from the first stripping tower to a second stripping tower, said second stripping tower providing controlled amounts of acid that reacts with gaseous ammonia;
- and
- (d) recovering an ammonium salt produced from reacting the acid with gaseous ammonia in the first and second stripping tower.
Dependencies are inferred from the claim text.