Schwing Bioset, Inc. Eric Wanstrom Schwing Bioset, Inc.

Transcription

1 Schwing Bioset, Inc Eric Wanstrom Schwing Bioset, Inc.

2 Nutrient (struvite) Recovery In partnership with:

3 Nutrient Recovery

4 Integrated Phosphate Management What are the Issues: Waste water inlet Pre treatment Primary Sedimentation Aeration Tank Secondary Sedimentation Post treatment 1 Digester Biogas tank Cogen Case Specific Issues = Case Specific Approach Sludge Thickener 1. Phosphorus return load 2. Pipe clogging / scaling issues 3. Struvite grit accumulation Sludge Dewatering 4. Dewatering issues Bio-P 5. Stabilizing Bio-P process 6. Increased sludge with iron salt 4 6

5 Integrated Phosphate Management Plant Issues: Mechanical: Clogged pipes & damaged equipment Accumulations in tanks Regulatory: Reduced Phosphorous effluent limits Process: Poor dewatering characteristics resulting from biological phosphourus removal process

6 Nutrient Recovery

7 Integrated Phosphate Management Plant Opportunity: Struvite can be recovered by precipitating into prills High value fertilizer product with opportunity to market Improve dewaterbaility of biosolids Global steward of phosphate management

8 Integrated Phosphate Management Struvite recovery is a two stage process: Air Stripping Crystallization Two stages allow for: Greater process control Stabilize operations by limiting variables to control in each vessel Design flexibility to solve more/specific plant issues Process can be applied to Digestate streams, Filtrate streams or combination of both

9 Integrated Phosphate Management Features: Concentrations reduced to ~ ppm PO4-P regardless of starting concentrations on centrate applications Reduced to ~40 ppm on digestate applications

10 Integrated Phosphate Management Current Installations since Municipal installations (4 operating, 1 PO received) 5 Industrial installations Municipal Installation List: Apeldoorn, Netherlands (Hybrid Solution) Aaenmaas Beijersbos, Belgium (Centrate Solution) Aquafin Aartselaar, Belgium (Digestate Solution) Nieuwegein, Netherlands (Digestate Solution) Braunschweig, Germany (Centrate Solution)

11 Integrated Phosphate Management Three primary configurations: 1. Digestate Improved dewatering due to residual Mg Eliminate scaling Harvest up to 50% of produced struvite Tanks twice the size as operating on Centrate Reduce PO4-P levels to ppm regardless of starting concentration

12 Integrated Phosphate Management Three primary configurations: 2. Centrate Harvest up to 90% of produced struvite Air Stripper & Crystallizer tanks half the size as operating on digestate Does not help with dewatering performance Does not help with scaling control Reduce PO4-P levels to ppm regardless of starting concentration

13 Integrated Phosphate Management Three primary configurations: 3. Hybrid Harvest up to 90% of struvite produced in Crystallizer Crystallizer tank half the size as operating on digestate Prevents scaling Does not help with dewatering performance Reduce PO4-P levels to ppm regardless of starting concentration

14 Integrated Phosphate Management Struvite recovery is a two stage process: Stage 1: Stripping Reactor Blow air to remove CO 2 Raises ph to ph acts like an accelerator in a car Higher ph = faster reaction o Smaller prills Lower ph = slower reaction o Larger prills Air Stripper

15 Integrated Phosphate Management Stage 2: Crystallization & Settling Reactor Magnesium Chloride is added (MgCl 2 ) Mg reacts with P and N Pure struvite crystals are formed Crystals are recycled to grow like pearl Prills can be harvested and then: Washed Optionally dried Bagged or truck loaded Truck Load MgCl 2 Settler Crystallizer SBI Proprietary & Confidential Information

16 Apeldoorn Hybrid 1. Digester 2. Equalization tank 3. Stripping reactor 4. Pumps 5. Blowers 6. Odor control (not necessary can use plant odor control) SBI Proprietary & Confidential Information

17 Apeldoorn Hybrid Redundant pumps to transfer settled solids to dewatering. This struvite is not recovered and comes out of plant in dewatered biosolids SBI Proprietary & Confidential Information

18 Apeldoorn Hybrid Redundant blowers to pump air through diffusers within stripping tank. Air strips off the CO 2 and results in a ph increase to In this ph range the magnesium that is present in the sludge will react and form struvite crystals SBI Proprietary & Confidential Information

19 Apeldoorn Hybrid 1. MgCl 2 storage tank 2. Primary crystallization reactor 3. Settling tank 4. Buffer tank to ensure optimum flow to hydrocyclones (area #6) (only used when high recovery rates required) 5. Finished product truck loadout from area #6 6. Additional process equipment indoors SBI Proprietary & Confidential Information

20 SBI Proprietary & Confidential Information Aaenmaas Centrate

21 1. Air Stripper 2. Crystallization Reactors 3. MgCl 2 tank 4. MgCl 2 metering (wall mounted) 5. Blower 6. Product wash 7. Product loading SBI Proprietary & Confidential Information Aaenmaas Centrate

22 1. Air Stripper 2. Reaction Tank 3. Settling Tank 4. Agitator no bearing in liquid 5. Hydrocyclone SBI Proprietary & Confidential Information Aaenmaas Centrate

23 View from below 1. Air Stripper 2. Reaction Tank 3. Recycle SBI Proprietary & Confidential Information Aaenmaas Centrate

24 MgCl 2 dosing system 1. Mg tank 2. Parallel metering SBI Proprietary & Confidential Information Aaenmaas Centrate

25 Blower for Air Stripper SBI Proprietary & Confidential Information Aaenmaas Centrate

26 Process pumps Bottom of washer SBI Proprietary & Confidential Information Aaenmaas Centrate Finished product

27 Finished product to storage Transport in Classifying screw SBI Proprietary & Confidential Information Aaenmaas Centrate Washing zone

28 Typical grit washer SBI Proprietary & Confidential Information Aaenmaas Centrate

29 Pilot Unit

30 Struvite Recovery 5 GPM digestate mode 10 GPM Centrate mode Can harvest produced struvite Con operate in conjunction with screw press

31 Questions