Energy Efficiency in MBR Systems Brian Codianne 1

Energy Efficiency in MBR SystemsBrian Codianne

1

Designing Enviroquip® MBR SystemsEnergy Efficiency - Goals and Strategies

Energy Efficiency

• Energy Expended per volume of water treated

• Units of measure: kWh/m3

Impact of Improving Energy Efficiency Plant Flow (mgd) 1

Energy Cost ($/kWh) 0.07Energy Savings (kWh/m3) 0.01 0.05 0.1 0.5 1Cost Savings ($/Yr) 967$ 4,836$ 9,672$ 48,359$ 96,717$

Energy Cost ($/kWh) 0.08Energy Savings (kWh/m3) 0.01 0.05 0.1 0.5 1Cost Savings ($/Yr) 1,105$ 5,527$ 11,053$ 55,267$ 110,534$

Energy Cost ($/kWh) 0.09Energy Savings (kWh/m3) 0.01 0.05 0.1 0.5 1Cost Savings ($/Yr) 1,244$ 6,218$ 12,435$ 62,175$ 124,351$


1 kwh/m^3 saves $110,000

Non-MBR LoadsLoads needed for support of

biology, independent of permeate production

MixersMLR Pumps

Process Air Blowers

MBR LoadsLoads based on the rate of

permeate production

Permeate Pumps MBR Scour Air Blowers

MBR Loads vs. Non-MBR Loads


ES SMU (Single Deck)

1989 2001 2009-2011

SMU Scour

AirEnergy Usage

EK SMU (Double Deck)(Type 510 Cartridge)

RW SMU (Double Deck)(Type B2-515 Cartridge)

SP SMU (Modules)

KUBOTA = 0.22 – 0.40 kWh/m3

EQ MBR = 0.13 – 0.18 kWh/m3KUBOTA = 0.73 kWh/m3

Integration of New Kubota Products

Designing Enviroquip® MBR SystemsEnergy Efficiency – MBR Strategies

Impact of SMU Evolution on Energy

gpd at 14.7 gfd

kWh/m3 at 14.7 gfd

50700

.364

79280

.275

91960

.230

EK-400 EW-400 RW-400


Energy ProTM Configuration

Proportional Aeration Configuration

Provide Aeration and Permeate Turndown for Off-Design Point Operations


Energy ProTM

PA

PA

AX

AX

SB FC

MBR

MBR

MBR

INF

EFF

1/3 of capacity at low flow

2/3 of capacity at medium flow

Full capacity at high flow

MBR Zones Automatically Brought Online to Incrementally

Match Demand


Proportional Aeration

Low Intensity at Low Flux

Medium Intensity at Medium Flux

High Intensity at High Flux

.5QQ2Q

MBR


Impact of Proportional Aeration on SMU Energy

gpd at 14.7 gfd

kWh/m3 at 14.7 gfd(Kubota)

50700

.364

79280

.275

91960

.230

EK-400 EW-400 RW-400

kWh/m3 at 14.7 gfd(EQ Prop Air)

.214 .167 .144


1Q

2Q

3Q

6:00 12:00 18:00 24:00

Low Intensity

Medium Intensity

High Intensity

PA

PA

AX

AX

SBFC

INF

EFF

MBR

MBR

MBR


0.00

0.50

1.00

1.50

2.00

2.50

3.00

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

1.10

1.20

1.30

1.40

1.50

1.60

Daily Flow (MGD)

En

erg

y C

on

sum

pti

on

(kW

h/m

3)

Avg. SBR Energy Usage 2001-2005 (0.80kWh/m3)

Enviroquip MBR Energy Usage

Actual Total Plant Energy Usage at Design AAF (1.5 MGD)

Dundee, MI – Efficiency and Turndown


Apr-08

May-08

Jun-08

2008 Energy Data

2007 Energy Data

0.00

1.00

2.00

3.00

4.00

5.00

6.00

To

tal P

lan

t E

ner

gy

Usa

ge

(kW

h/m

3)

2008 Energy Data2007 Energy Data

Delphos, OH – Efficiency and Turndown(Energy Audit Excerpt)


Pump Assisted Gravity Configurations

Maximizing Efficiency at Design Points


Permeate Collection Methods

Gravity

P

Pumped

Pumping Energy to Convey Permeate

Low SWD

No Pumping Costs

High SWD


Pump Assisted Gravity (PAG)

PAG is ~25% more energy efficient than gravity or pumped systems

• Lower blower discharge pressure

• Pumps only used to resolve air lock/high TMP

P


EQProSim™

Inputs Diurnal Flows Working Volume (EQ) Permeate CapacityOutput Minute to Minute Status Total Run Times Accurate Energy Prediction

Use system modeling to optimize controls and hydraulic balancing


EQProSim™

Design Optimization Determine Optimum EQ

volume for diurnal flows (hydraulic balance, energy)

Prediction of energy consumption at design and off-design points

Cost-benefit analysis of using various configurations (EnergyProTM, Proportional Aerations, etc.)


High Efficiency Blowers Turbo and next-generation PD blowers 15-30% less energy than traditional PD blowers

Added Benefits Integrated VFDs (lower MCC cost) Integrated pressure and flow sensors Smaller footprint (less building costs)

Incorporating evolving technologies and configurations


• EK SMU (DD)• Optimize

SRT/MLSS• Biomonitoring

2001

MBR System Energy Usage

2004-2005

• EW SMU• Proportional

Aeration• Pump-Assisted

Gravity

+20% Efficiency

2006-2009

• RW SMU• Energy Pro™• PAD-K

+40% Efficiency

• SP SMU• ECOBLOX™• microBLOX™

2011-2012

+40% Efficiency ??


Designing Enviroquip® MBR SystemsEnergy Efficiency – Overall Strategies

Improving Non-MBR Efficiencies

Mixers Optimizing mixer speeds/energy input to match process needs Ovivo LM Mixers

Mixed Liquor Recycle Installing turn-down in pumping rates for seasonal changes in flows

Process Aeration Maximizing fine bubble SOTE to reduce aeration energy Minimizing energy burned through control valves (basin SWDs) Improve blower/FCV interactions – Most Open Valve Control

Compounding Factors

• Running at higher than necessary DO• If pre-aeration basin DO is 6 mg/l instead of 2 mg/l – 84% more energy consumption

• Running at a higher aeration header set point than necessary• In a 16’ SWD basin, each additional .1 psig = 1.25% more energy• In an 8’ SWD basin, each additional .1 psig = 2.6% more energy

• Balancing differing basin SWDs with FCVs on the same aeration headers• First basin at 16’ + second basin at 15’ = 6% expended energy across FCV• First basin at 10’ + second basin at 9’ = 10% expended energy across FCV• First basin at 16’ + second basin at 8’ = 87% expended energy across FCV

• Inability to turn-down mixed-liquor recycle flow rates• MLR rate based on daily Q total. Operating at 50% capacity = need for 50% of MLR

• Operating with less efficient equipment• Older PD blowers compared to newer turbofan blowers = 10% - 30% additional energy

Designing Enviroquip® MBR SystemsEnergy Efficiency – Theory vs. Reality

Analysis of Energy-Related Alternatives

Cost/benefits of:

• Energy Pro™ and Proportional Aeration Configurations

• Segregation of aeration systems by operating depths

• Installation of mixed liquor recycle flow turn down

• Installation of mixers sized for basin

• Utilization of higher-efficiency motors and technologies

Utilize Ovivo as a Design Resource

Designing Enviroquip® MBR SystemsEnergy Efficiency – Designing for Reality

Thank You

Brian CodianneSenior Technologist, MBR Systems

[email protected]

Documents

Energy Efficiency in MBR Systems Brian Codianne 1