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US 12,338,147 B2Granted
Digestion of organic sludge
AssigneeHaskoningDHV Nederland B.V.
InventorsAntonius Theodorus Wilhelminus Maria Hendriks, Eddie Koornneef
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Abstract
The invention is in the field of organic sludge digestion from various sources, such as manure, sludge from a wastewater treatment plant, and an organic fraction of dredging sludge. The present method provides advanced control for serially treating aqueous organic sludge by anaerobic digestion. It further relates to dewatering of the obtained biomass.
Claims20
A method for serially treating aqueous organic sludge by anaerobic digestion, comprising
- (a1) feeding input sludge through a fluidic connection to a first digestion reactor in a series of N digestion reactors and feeding a controlled part of the input sludge through a fluidic connection to a second digestion reactor, wherein N≥2,
- (a2) feeding an effluent of an nth digestion reactor through a fluidic connection to an n+1th digestion reactor, wherein n is an element of [1,N],
- (a3) feeding a controlled part of the effluent of the Nth digestion reactor through a fluidic connection to at least one lower ranked digestion reactor,
- (a4) feeding a controlled part of an effluent of the second digestion reactor through a fluidic connection to the first digestion reactor,
- (a5) removing a controlled part of 30-100% of the effluent of the Nth digestion reactor from the series of N digestion reactors,
- (b) controlling at least one of the group of feeding and removing
- by (b1) obtaining concentration of fatty acids, and at least two values of (b11) pH, an amount of dry sludge in the feed, temperature of at least one digestion reactor, and type of input sludge, and
- by (b2) regulating a fluid level in at least one digestion reactor to prevent overflow of an nth reactor to a subsequent n+1th reactor and by regulating a fluid level by at least one parameter selected from at least one flow, an amount of sludge in a digestion reactor, and an amount of anti-foam in a digestion reactor, wherein a flow is selected from flows a1-a5, and
- (c) digesting the organic sludge, during a period of time of more than 3 days, wherein a total solid retention time for digestion is a period of time of 3-21 days, in at least one of the series of N digestion reactors, at a temperature from 20-70° C.
6 more elements
A reactor set-up for serially treating aqueous organic sludge by anaerobic digestion, comprising
- a series of N digestion reactors, wherein N≥2,
- between an nth digestion reactor and an n+1th digestion reactor a fluidic connection,
- a sludge input for the first digestion reactor,
- an effluent output for the Nth digestion reactor,
- a fluidic effluent connection between the second digestion reactor and the first digestion reactor,
- a fluidic effluent connection between the Nth digestion reactor and at least one lower ranked digestion reactor,
- at least one controller for controlling at least one of the group of feeding and removing
- by obtaining at least two values of pH, an amount of dry sludge in the feed, temperature of at least one digestion reactor, type of input sludge, and wherein values are obtained of at least one of the sludge in the input and of at least the first of the N digestion reactors, and
- by regulating a fluid level in at least one digestion reactor to prevent overflow of an nth reactor to a subsequent n+1th reactor and a parameter selected from at least one flow, an amount of sludge in a digestion reactor, an amount of anti-foam in a digestion reactor, and combinations thereof, wherein a flow is selected from feed and removal flows to and from the N digestion reactors, and for controlling dewatering by obtaining values of pH and redox values, wherein values are obtained of at least one of the sludge in the input and of at least the first of the N digestion reactors, and by regulating a flow between at least one Nth digestion reactor and post-digester and dewatering apparatus,
- at least one heater for digesting the organic sludge in at least one digestion reactor at a temperature from 20-70° C. during a period of time of more than 3 days, and
- at least one pump for providing flow.
8 more elements
Dependencies are inferred from the claim text.