nywea energy specialty conference november 20, 2014 towards net-zero energy in wastewater treatment...
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Demonstration CCS EPT Pilot Anaerobic Digestion Pilots Biochemical Methane Potential Testing 11/20/2014 2TRANSCRIPT
NYWEA ENERGY SPECIALTY CONFERENCE
November 20, 2014
Towards Net-Zero Energy in Wastewater Treatment
Demonstration of ClearCove’s Enhanced Primary Treatment Technology
Alex Wright, ClearCove Systems & Mark Greene, O’Brien & Gere
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Enhanced Primary
Treatment
• Benefits– Divert digestible material
• from secondary treatment
• to anaerobic digestion
– Higher TSS and BOD removal
– Coagulant addition leads to phosphorus removal
• Key Impact Areas of Evaluation– Chemical costs
– Hydraulic profile
– Readily degradable organics for N-removal
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Demonstration• CCS EPT Pilot
• Anaerobic Digestion Pilots
• Biochemical Methane Potential Testing
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EPT Pilot • 20,000 gal/day• Equalizes the flow • Stops the Flow• Removes 100% of the grit • Removes 100% of the fibers• Settles the high value organics
– Phys/Chem: chemical dosing and gravity– Colloidal capture
• Filters the effluent – 50 micron screen– Membrane Operation Benefit
• Removes the sludge to a classifying press
– Removes additional digestible organics– Removes and dewaters gross matter
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EPT Pilot• Wastewater pumped from influent
channel of IAWWTF• Wastewater enters both sides of the
tanks through the Influent Feed Chamber.
• Grit and dense solids settle out• Wastewater flows over 70 degree
weirs into the main chamber of the tank where the lighter solids settle out
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EPT Pilot • Screen box is lowered into low BOD, low solids supernatant after the settling period
• Wastewater flows through the screen and down a central effluent hose
• 50 micron stainless steel screen
• Air scour to deflect any floating material from coming in contact with screen
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Ithaca Influent Wastewater
Ithaca NY Results ClearCove’sEPT Effluent
The Best Biomass gets destroyed!
Suspended “Fuel”
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ClearCove Results
Ithaca Primary Effluent
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Sludge Classifying Press
• Sludge from the EPT unit is processed through SCP
• SCP “cleans” sludge, removing inorganic solids and releasing encased organics.
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Pilot Digesters • 4 Fixed Volume Reactors
– 300-gallon, cone bottom– 100-gallon operating volume
• Hydraulic Mixing• Heating using IAWWTF hot water• Data logging for biogas flow and
digester temperature• Biogas measurements taken every
10 seconds (over 1 million readings over the course of the project)
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Pilot Digesters • Four (4) Feed Tanks
• Hydraulic Mixing• Solenoid valve diversion
to digester• Feedstock transfer by
buckets
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BMP• Bioprocess Control
– Automatic Methane Potential Test System (AMPTS II)
• (15) 640 ml reactors including controls
• Used to validate and correlate the digester pilot data
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Results• CCS EPT Pilot
• Anaerobic Digestion Pilots
• Biochemical Methane Potential Testing
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EPT/SCP Pilot Flow Schematic
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Mini-Digester Flow SchematicTwo test units and two control units
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Plant Impacts• CCS EPT Pilot
• Anaerobic Digestion Pilots
• Biochemical Methane Potential Testing
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Actiflo
BACKWASH
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Chemical Impact
• Current use
– 400-500 GPD Ferric Chloride
• Actiflo process
• 700 GPD peak
– 50-100 GPD Ferrous Sulfate
• Headworks
• Estimated use with EPT
– 400 GPD Ferric Chloride
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Reduction in Aeration Electricity IAWWTF uses 9,400 kWh/day
Aeration accounts for 48% (submetering) 72% for BOD removal (O2 demand)
28% for nitrification (O2 demand)
BOD removal in existing aeration 5,960 lb/day, 3,275 kWh/day
Energy = 0.55 kWh/lbrem
BOD removal with EPT 2,290 lb/day, 0.55 kWh/lbrem
Energy = 1,260 kWh/day
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-62%
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Volatile SolidsCurrent
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• Mass Balance• Thousand Lb/day
• Gravity Primary Clarifiers• 28% VS capture
• Gravity Thickener• 43% VS capture
• Thickened Solids• 67% primary
• 33% secondary
7.3
18.8
26.1 6.1
9.517.0 30.0
13.0
19.5
60,000 scfd
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Volatile SolidsEPT
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• Mass Balance• Thousand Lb/day
• Enhanced Primary Clarifiers• 84% VS capture
• Gravity Thickener• 43% VS capture
• Thickened Solids• 82% primary
• 18% secondary
7.3
18.9
26.2 1.5
5.017.0 30.8
13.6
24.7
100,000 scfd
EPT
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26%
-45%
2.4x
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Energy Production Potential
2.4 times
4.Xtimes
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EPT Demonstration
Summary
• Sufficient amount of data collected
• Pilot EPT: 84% TSS removal
67% BOD5 removal
76% TP removal
• Primary sludge fraction of digester feed
– 67% current
– 82% with EPT
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Digestion Demonstration
Summary
• BMP Results
– IAWWTF Primary Sludge• 4.4 scf methane per lb VS fed
– Enhanced Primary Sludge• 6.6 scf methane per lb VS fed
– Statistically different with 95% probability
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Digestion Demonstration
Summary
• Pilot Results
– IAWWTF Primary Sludge• 4.1 scf methane per lb VS fed
• 13.4 scf methane per lb VS destroyed
– Enhanced Primary Sludge• 8.3 scf methane per lb VS fed
• 28.4 scf methane per lb VS destroyed
– Statistically different with 95% probability
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IAWWTF Impacts Summary
• Secondary Treatment Costs
– Decrease by 62%
– Savings of approx. $125,000/year
• Methane Generation from Primary Sludge
– Increase by 2.4x
• $325,000/year in kWh value
– Optimized upside potential is 4.5x
• $625,000/year in kWh value
* CNG economic $ value would be ~2x
– Potential for greater amount• Improved thickening
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Thank you!
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Rethink. Reduce. Renew.
Alex Wright, [email protected], (585) 269-8176
Mark Greene, [email protected], (315) 956-6271