Carbon is Best Used for Biological Nutrient Removal at the … · 2019-05-15 · Carbon is Best...
Transcript of Carbon is Best Used for Biological Nutrient Removal at the … · 2019-05-15 · Carbon is Best...
5/13/2019
VWEA Education Seminar 2019 1
Carbon is Best Used for Biological Nutrient Removal at the Nansemond Treatment Plant
Beverley StinsonWendell Khunjar
Opening Argument
(Appetizer)
1. Carbon for BNR is more cost effective
2. Enhanced Biological Phosphorus Removal (EBPR) facilitates P recovery, a limited, high value resource, so better for the environment and food supply
3. Reduced GHG emissions by
• Offset chemical fertilizer production• Reduced ferric & methanol chemical• Reduced trucking
4. EBPR sets us up for high value carbon recovery and reuse
5. We are on the verge of having it all
• Energy Neutrality• Nutrient Removal / Recovery • High Value Carbon Recovery• Reduced GHG emissions
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VWEA Education Seminar 2019 2
Effective carbon management is central to WRRFs of the future
Anaerobic
digester
Effluent
~50%
Biogas
100% ~50%~5%
~25%
~20%
~37%
Biosolids
Do we attempt to recover
as much energy in the
influent carbon through
biogas production?
Do we use the carbon
for nutrient removal
and recovery?
What is the role of high
value carbon recovery in
WRRFs?
The industry trend is towards maximizing beneficial recovery of the carbon as biogas…
Anaerobic
digester
Effluent
~50%
Biogas
100% ~50%~5%
~25%
~20%
~37%
Biosolids
Maximize energy
recovery from biogas
Minimize carbon use
for nutrient control
Energy purchased
Energy produced
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VWEA Education Seminar 2019 3
The new resource management paradigm is upon us
Source
water
Drinking
Water
Treatment
Wastewater
Generation
Water
Biosolids
Energy
Nutrient Products
Water
Resource
Recovery
Facility
High Value Carbon Products
e.g., bioplastics, cellulose
Industry Trend Assumes…
These assumptions are not valid at all WRRFs
Offsetting energy purchases is highest
priority at utility
Harvesting chemical energy is best means for
achieving purchased energy neutrality
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VWEA Education Seminar 2019 4
A Tale of Two ENR Plants
A-B Plant for maximum carbon capture and digestion
• Digestion + CHP
• Methanol to drive denitrification
• Alum to precipitate P
5-stage Bardenpho Plant
• No chemical addition
• No Digestion
Influent Q = 1 MGD
Effluent TN = 3.0 mg/L
Effluent TP = 0.3 mg/L
A-B Plant – Focused on Maximizing Energy Recovery
Digestion + CHP
Item (Unit) Carbon for Power
Total Pumping Power (hp) 28
Total Blower Power (hp) 24
Total Misc. Power (hp) 11
Total Power Demand (hp) 63
Energy/Volume Treated (kWh/MG) 1,126
Methanol Usage (gpd) 15
Secondary Alum Usage (gpd) 123
Tertiary Alum Usage (gpd) 68
Digester Biogas (ft3/d) 16,760
Digester Heating Power Requirement (hp) 48
CHP Heat Power Generated (hp) 61
CHP Electricity Generated (hp) 54
Net Power Purchased from Grid (hp) 9
Net Total Power Emissions (TCO2eq/y) 1,210
Sludge Disposal (DT/d) 0.75
Sludge Disposal (WT/d) 4.1
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VWEA Education Seminar 2019 5
5-Stage Bardenpho Plant
NO Digestion + CHP
Item (Unit)Carbon to Drive
ENR
Total Pumping Power (hp) 22
Total Blower Power (hp) 29
Total Misc. Power (hp) 19
Total Power Demand (hp) 70
Energy/Volume Treated (kWh/MG) 1,248
Methanol Usage (gpd) 0
Secondary Alum Usage (gpd) 0
Tertiary Alum Usage (gpd) 0
Digester Biogas (ft3/d) 0
Digester Heating Power Requirement (hp) 0
CHP Heat Power Generated (hp) 0
CHP Electricity Generated (hp) 0
Net Power Purchased from Grid (hp) 70
Net Total Power Emissions (TCO2eq/y) 1,940
Sludge Disposal (DT/d) 0.68
Sludge Disposal (WT/d) 3.8
Breakdown of Annual Costs
Carbon for power only is not always the best value solution
Important to consider ALL priorities
ItemCarbon for
CHPCarbon to Drive ENR
Net Power Cost (@$0.10/kWh) $ 5,849 $ 45,569
Methanol Cost (@ $1.13/gal) $ 6,187 $ -
Alum Cost (@ $1.12/gal) $ 78,196 $ -
Sludge Disposal Cost (@ $50/WT) $ 75,548 $ 69,072
Total Annual Costs $ 165,780 $ 114,642
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VWEA Education Seminar 2019 6
eutrophication
Today, we will demonstrate that carbon for BNR provides the best value for Nansemond Treatment Plant
Offsets need for supplemental
carbon
Reduces aeration and
alkalinity addition
Supports Bio-P and struvite
recovery
Best leverages existing
infrastructure
Evidence Presentation
(Main Course)
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VWEA Education Seminar 2019 7
Nansemond WWTP is a 30 MGD facility that employs a 5-stage BNR for N and P removal
Quick Facts About Current Operation at NTP
Future Effluent TN target ~ 4.0 mg/L
Future Effluent TP target ~ 1.0 mg/L
Current Flow
~ 18 mgd
PC %TSS removal
~ 50%
Effluent NutrientTN ~ 6.5 mg/L (average)
TP < 0.9 mg/L (average)
Struvite produced
~ 850 lb/day
Methanol demand
~ 820 gal/day
Energy demand
~ 2,500 kW/MG
Biogas production
~ 14 ft3/lb VSR
Cake production
~ 1,300 lb TS/MG
Digester HRT
~ 17 day
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VWEA Education Seminar 2019 8
Biological treatment is the biggest energy sink at the NTP
• Similar profile to most ENR WRRFs
• Tempting to use this to assign priority to carbon use
• But we need the whole picture
Approximate based on flows/concentration
Implementing BNR optimization can reduce energy needs onsite
1,334
1,697
1,876
1,947
5,676
870
1,075
1,133
1,198
2,815
0 1,000 2,000 3,000 4,000 5,000 6,000
BOD-removal only
Nitrification
BNR
ENR
MBR
B1
F1
G1
M1
N1
Electric Intensity (kWh/MG)
Typical
40% average reduction by implementing best practices
(35% reduction)
(37% red.)
(40% red.)
(38% red.)
(50% red.)
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VWEA Education Seminar 2019 9
Offsetting supplemental carbon should be the first priority at NTP at current market prices
Highest value to offset supplemental carbon first
followed by electricity
Significant amount of energy embedded in biosolids that not currently extracted
$0.06/kWh$1.30/gal MicroC3000
Heat already generated onsite offsets
electricity purchases
What is the break even point for energy vs. BNR?
Electricity @ $0.06/kWh
$0.075/kWh
Supplemental Carbon @ $1.30/gal
Under current market conditions, NTP should continue to
utilize influent carbon to offset BNR needs as a #1 priority
Continue to use biogas to offset heating requirements
Consider processes that extract value from biosolids
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VWEA Education Seminar 2019 10
Key Evidence
1. Carbon for BNR is more cost effective
2. Enhanced Biological Phosphorus Removal (EBPR) facilitates P recovery, a limited high value resource, so better for the environment and food supply
3. Reduced GHG emissions by
• Offset chemical fertilizer production• Reduced chemical production • Reduced trucking
4. EBPR sets us up for high value carbon recovery and reuse
5. We are on the verge of having it all
• Energy Neutrality• Nutrient Removal / Recovery • High Value Carbon Recovery• Reduced GHG emissions
The new resource management paradigm is upon us
Source
water
Drinking
Water
Treatment
Wastewater
Generation
Water
Biosolids
Energy
Nutrient Products
Water
Resource
Recovery
Facility
High Value Carbon Products
e.g., bioplastics, cellulose
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VWEA Education Seminar 2019 11
We are at the Nexus of the Water-Food-Energy Paradigm
Source: US Census Bureau, International Data Base, 2006 UN Global Forecast, 2004
10
8
6
4
2
0
1950 1970 1990 2010 2030 2050
9.45 Billion
70% UrbanGlobalPopulation
Urban Population
Year
Po
pu
lati
on
in
Bil
lio
ns
• 50% increase in population by 2050
– 9 Billion
• Water demand growing at twice the
rate of population growth
• By 2030, the 8 billion people living
on earth will need
• 30% more water
• 40% more energy
• 50% more food
• Until recently believed that there was less than 100 years of phosphorus reserves
• China recently doubled tariffs on phosphorus exports
• Price of Phosphate rock has soared over past couple of years
• Phosphorus is key to Food Security – Water / Food / Energy Nexus
Enhanced Nutrient Recovery – Food Security
Phosphorus production – 90% in 5 regions. Source IFDC.
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VWEA Education Seminar 2019 12
Haber Bosch Process for Ammonia Fertilizer Production
• 1-2% of Global Energy Demand
• 3% Global Natural Gas demand
• 5% CO2 Emissions
Ammonia Fertilizer Production1945 to 2010
Key Evidence
1. Carbon for BNR is more cost effective
2. Enhanced Biological Phosphorus Removal (EBPR) facilitates P recovery, a limited high value resource, so better for the environment and food supply
3. Reduced GHG emissions by
• Offset chemical fertilizer production• Reduced chemical production • Reduced trucking
4. EBPR sets us up for high value carbon recovery and reuse
5. We are on the verge of having it all
• Energy Neutrality• Nutrient Removal / Recovery • High Value Carbon Recovery• Reduced GHG emissions
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VWEA Education Seminar 2019 13
25
25
Biofuels
Engineering Microbial Processes to Recover High Value Carbon Products
Biogrout, SmartSoils®Commercial Chemicals,
Solvents, Lipids, BioisopreneBioplastics
BioFertilizers®Electricity
Looking into the future…
* Assumes 100% acetic acid; **Assumes polyhydroxybutyrate
Fermentation
Unprocessed
Carbon
Bioplastic pre-
cursors
Volatile Fatty Acids
$56 to 180/MMBTU
$390 to 490/MMBTU
Biogas (methane)
$5 to 50/MMBTU
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VWEA Education Seminar 2019 14
How would we facilitate recovery of VFA and PHA at WRRFs?
PS
Raw Influent To disinfection
Secondary
treatment
WAS
Anaerobic
digestion DewateringSidestream
Biosolids
disposalFermentation
PHA
Production
PHA Rich
Biomass
High Strength
Waste
HSW Character
Sludge Character
Process Stoichiometry
Energy/Commodity Data
Energy Product
Carbon Product
Biosolids Impacts
BNR Impacts
Capital and O&M Req’s
Descriptive life cycle economics
How do the economics of recovery impact implementation of VFA or PHA recovery?
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VWEA Education Seminar 2019 15
-1,000,000
-500,000
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
3,500,000
2017 2022 2027 2032 2037
Ne
t P
rese
nt
Co
st
($)
Years
VFA (supplemental)
VFA (purified)
PHA (purified)
Economics of VFA and PHA Recovery at 5 Stage ENR
VFA yield = 0.20 lb VFA/lbpCOD
PHA yield = 0.15 lb VFA/lb VFA
VFA pays back within 15 year
PHA does not payback
Economics of VFA and PHA Recovery at 5 Stage ENR
VFA yield = 0.25 lb VFA/lb pCOD
PHA yield = 0.15 lb VFA/lb VFA
VFA pays back within 10 to 12 year
PHA can pay back within 20 year period-1,000,000
-500,000
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
3,500,000
2017 2022 2027 2032 2037
Ne
t P
rese
nt
Co
st
($)
Years
VFA (supplemental)
VFA (purified)
PHA (purified)
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VWEA Education Seminar 2019 16
Key Evidence
1. Carbon for BNR is more cost effective
2. Enhanced Biological Phosphorus Removal (EBPR) facilitates P recovery, a limited high value resource, so better for the environment and food supply
3. Reduced GHG emissions by
• Offset chemical fertilizer production• Reduced chemical production • Reduced trucking
4. EBPR sets us up for high value carbon recovery and reuse
5. We are on the verge of having it all
• Energy Neutrality• Nutrient Removal / Recovery • High Value Carbon Recovery• Reduced GHG emissions
32
32
WERF Electrical NeutralityPower for TreatmentPower ProducedNeutrality = 26%
BNR w/CHP – Typical
5760kWh/d
12996 kWh/d
584kWh/d
3195 kWh/d
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VWEA Education Seminar 2019 17
33
33
Pioneering modules: ●CEPT●FOG and Food Processing Waste Co-digestion (market-limited) ●Thermal Hydrolysis Pretreatment (THP) ●Wastewater Heat Recovery (Adsorption Chiller) ●ADD – FERMENTATION TO GRAVITY THICKENER
WERF Electrical NeutralityPower for TreatmentPower ProducedNeutrality = 61%
4149 kWh/d
584 kWh/d
7404 kWh/d
BNR w/CHP & Best Practices +++ Pioneering Module
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VWEA Education Seminar 2019 18
Can we achieve both goals?
Reduce energy and carbon demand with innovative technologies
Membrane aerated biofilm
reactors (MABR)Mainstream
Deammonification
Anaerobic ammonia
oxidation
1 lb Ammonia (NH3-N)
1/2 lb Nitrite (NO2--N)
1/2 lb Nitrogen gas (N2)
&
Small amount of Nitrate
37.5% O2nitritation
Carbon for BNR provides the best value for Nansemond Treatment Plant
Offsets need for supplemental
carbon
Reduces aeration and
alkalinity addition
Supports Bio-P and struvite
recovery
Best leverages existing
infrastructure
Positions for future carbon
economy
Under current market conditions, NTP should
continue to utilize influent carbon to offset BNR
needs as a #1 priority
Optimize and reduce energy demand
Continue to use biogas to offset heating requirements
Consider processes that extract value from biosolids
5/13/2019
VWEA Education Seminar 2019 19
Closing Argument
(Dessert)
Evidence has proven that:
Carbon for BNR is more cost effective
Enhanced Biological Phosphorus Removal (EBPR) facilitates P recovery, a limited high value resource, so better for the environment and food supply
Reduced GHG emissions by
• Offset chemical fertilizer production• Reduced chemical production • Reduced trucking
EBPR sets us up for high value carbon recovery and reuse
We are on the verge of having it all
• Energy Neutrality• Nutrient Removal / Recovery • High Value Carbon Recovery• Reduced GHG emissions
Carbon for BNR provides the best value for Nansemond Treatment Plant
Offsets need for supplemental
carbon
Reduces aeration and
alkalinity addition
Supports Bio-P and struvite
recovery
Best leverages existing
infrastructure
Positions for future carbon
economy
Under current market conditions, NTP should
continue to utilize influent carbon to offset BNR
needs as a #1 priority
Optimize and reduce energy demand
Continue to use biogas to offset heating requirements
Consider processes that extract value from biosolids
5/13/2019
VWEA Education Seminar 2019 20
39
39
Biofuels
Engineering Microbial Processes to Synthesize High Value Carbon Products
Biogrout, SmartSoils®Commercial Chemicals,
Solvents, Lipids, BioisopreneBioplastics
BioFertilizers®Electricity
We foresee that we can have it all -Energy Neutrality & Nutrient Removal
Reduce energy and carbon demand with innovative technologies
Membrane aerated biofilm
reactors (MABR)Mainstream
Deammonification
Anaerobic ammonia
oxidation
1 lb Ammonia (NH3-N)
1/2 lb Nitrite (NO2--N)
1/2 lb Nitrogen gas (N2)
&
Small amount of Nitrate
37.5% O2nitritation
5/13/2019
VWEA Education Seminar 2019 21
We Rest Our Case
Your Honour