nbp integrated webcast power point 042512 - wefnet.org april 25, 2012/nbp integrated webcast...
TRANSCRIPT
4/23/2012
1
National Biosolids PartnershipWebcast
“Thermal Hydrolysis Comes to America: DC Water’s Blue Plains Digestion
Project”
April 25, 2012
2
Sam Hadeed
Biosolids Program Manager Water Environment FederationNational Biosolids PartnershipAlexandria, VA
WEF Residuals & Biosolids Committee Staff Liaison
WELCOMING REMARKS
Starting in January 2010, NBP began offering a series of ”no charge” quarterly webcasts devoted to general biosolids management and technical topics of interest to water quality and biosolids professionals:• Carbon Footprint Implications from Biosolids Management Practices• Advances in Solids Reduction Processes• Combined Heat and Power Generation Opportunities at Wastewater Treatment
Facilities• Charting the Future of Biosolids Management: Forum - Findings on Trends and
Drivers• Implementing the New SSI MACT Standards – Issues and Challenges Ahead• Terminal Island Renewable Energy – LA’s Biosolids Slurry and Brine Injection
Project• Renewable Green Energy from Biosolids – POTW Case Studies to Achieve Net
Energy Production• When Opportunity Knocks, How Can Municipalities and POTWs Partner with
the Biofuels Industry
2.0 Professional Development Hours for this webcast
http://www.wef.net/nbp/
NBP’s Commitment to Excellence in Biosolids Management
4
NBP - WEF Resources for Biosolids Management
www.biosolids.org – NBP Web Page and E-Newsletter
www.wef.org - Biosolids Channel of Access Water Knowledge
WEFTEC 2012 September 29-October 3, 2012New Orleans, Louisiana http://www.weftec.org
4/23/2012
2
Alexandria, VA Sanitation Authority King County, WA Div. WW TreatmentCity of Santa Rosa, CA Public Utilities Louisville & Jefferson Co. KY Metro Sewer DistrictCity of Wyoming, MI Clean Water Plant Madison, WI Metropolitan Sewerage DistrictCentral Davis County, UT Sewer District Metro Denver, CO WW Reclamation District Columbus, GA Water Works Metro Water Reclamation Dist. of Greater Chicago, ILDC Water Orange County, CA Sanitation DistrictNew England Organic Hawk Ridge Composting Facility Orange County, FL UtilitiesWater Environment Services of Clackamas County, OR Resource Management Inc., NH East Bay Municipal Utility District - Oakland, CA Kent County, DE Regional WTFButler County, OH DES Encina Wastewater Authority – Carlsbad, CACity of Albany, OR Wastewater Treatment Plant City of Raleigh, NC Public Utilities DepartmentCity of Chattanooga, TN DPW City of Mankato, MNCity of Fort Worth, TX Water Dept City of Los Angeles, CA Dept of Public WorksCity of Grand Rapids, MI City of Lawrence, KS Dept. of UtilitiesGreater Moncton Sewerage Commission, Canada Lewiston-Auburn, ME WPA Camden County, NJ Municipal Utility District City of Richmond, VA Public Utilities Dept.Renewable Water Resources – Greenville, SC Knoxville Utilities Board, TN
NBP EMS Certified Agencies (34)
A key component of the NBP program is the EMS and third-party audit program. The following agencies/organizations have achieved the prestigious NBP EMS certification.
Thermal Hydrolysis Comes to America: DC Water’s Blue Plains Digestion Project
Learning Objectives
• This webinar will focus on the benefits of thermal hydrolysis from multiple perspectives including:• An owner that has selected the technology, • A company that provides thermal hydrolysis engineered systems, and • Design firms responsible for designing and constructing the first system in North America.
• Other owners and engineers considering thermal hydrolysis would gain an understanding of the issues of:• Cost• Digester and equipment requirements (digester size, pre and post dewatering, heating and
cooling requirements), • Biogas production potential, • Biosolids characteristics, • Odor control, and • Solids reduction.
Today’s Webcast
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Walt Bailey
Director, Department of Wastewater TreatmentDC Water – Blue PlainsWashington, DC
“How DC Water Decided to Choose Thermal Hydrolysis (Cost Minimization,
Product Quality, Green Energy”
TODAY’S SPEAKERS
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Keith Panter
International Biosolids Consultant, Managing DirectorCambi - Ebcor LtdCheshire, United Kingdom
“What is Thermal Hydrolysis and Where is it Used?”
TODAY’S SPEAKERS
4/23/2012
3
9
Perry Schafer
Vice-President Brown & CaldwellRancho Cordova, CA
“Procurement Challenges and Innovations”
TODAY’S SPEAKERS
10
Peter Loomis
Senior Project Manager CDM SmithFalls Church, VA
“Design & Construction Considerations”
TODAY’S SPEAKERS
11
Dave Parry
Wastewater and Energy Market Leader, Senior Vice PresidentCDM SmithBellevue, WA
“Design & Construction Considerations”
TODAY’S SPEAKERS
Walter Bailey, PE, BCEE, WEF Fellow Assistant General Manager-Blue Plains
DC Water and Sewer AuthorityApril 25, 2012
4/23/2012
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Review of Blue Plains AWTP and Service Area Development of Anaerobic Digestion Program R&D Work for the Biosolids Program Due Diligence on Thermal Hydrolysis Recommended Program to use TH/Digestion
Operated by DC Water 391mgd (ADWF capacity) ~160 acre site Largest Advanced
WWTP in the world
14
2.2 million pop served (4 million “Population Equivalent”)
Includes all of the District of Columbia and portions of Virginia and Maryland suburbs
A portion of the service area has combined sewers Source: DCWater.com
4/23/2012
5
Large-scale Class B lime stabilization–product largely used in land application
About 65 truck-loads per day (1200 wet tons/day)
Staff has greatly minimized product odors over the years
EMS certification of DC Water Biosolids Program in 2004
17
NPDES Permit ~4.2 mg/l TN (Mass-based Limits)
P-removalNPDES limit < 0.18 mg/l
18
New Filtrate Treatment Process
$84 million
BP Tunnel Dewatering Pump Station & Enhanced Clarification Facility
$300 million
Upgrade & expansion of the Nit/ Denit system
Upgrade of the Secondary High Rate System
$26 million
New Biosolids Management Program
$460 million Dual Purpose Sed Basins Upgrade
$18 million-
Enhanced Nutrient RemovalFacilities
$340 million
1999 BMP recommended implementing new Class B anaerobic digestion to greatly reduce quantities
Continue land application as long as viable with Class B Biosolids
2000 – old (1938) digesters shut down-safety concerns, inadequate capacity, and odorous product with centrifuge dewatering
All biosolids since that time have been Class B lime-stabilized
4/23/2012
6
Developed plans for large egg-shaped digestion project by 2006-45 MG of tankage
Research showed that with centrifuge dewatering, odor regrowth would be a problem, and also pathogen indictor regrowth/resuscitation
Costs escalated, and with limited competition, the project became too costly.
Research starting 2002 under Dr. Sudhir Murthy’s direction at DC Water-WERF/other funding
Tested many digestion and dewatering process options at lab-scale
Work by VA Tech (Novak/team) Bucknell Univ. (Higgins/team) and others
Tracked development and performance of all pertinent processes including Thermal Hydrolysis (TH)
Tested over 50 process options at lab-scale (Wilson/Novak) Feedstock for all tests was Blue Plains solids
(primary and WAS) Included Thermal Hydrolysis + MAD
(evolution of work at Stanford Univ. and elsewhere)
0%
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TH + MAD was Eventually Selected
Extensive odor regrowth testing on digestion and dewatering processes.
Additional work on pathogen indicator densities following centrifuge dewatering confirmed regrowth/resuscitation potential for most digestion processes
Major work on dewatering combined with each digestion process tested
4/23/2012
7
DC Water recognized the need for biosolids product improvement and diversification over time
12 Alternatives developed/evaluated:◦ Various anaerobic digestion processes◦ Digestion pretreatment
including TH ◦ Thermal drying options◦ Many options used existing
lime stabilization capacity to handle peak/abnormal events
Employed expert panel as part of the evaluations
Evaluation included site visits at TH/digestion plants in the UK
Capital and annual O&M cost comparisons Energy use and renewable power production-key issues Space/footprint issues were critical for feasibility GHG emission calcs/comparisons Comparison for various risks,
O &M factors, plus sensitivity analyses Ability to produce low-odor product
and minimize indicator regrowth (only TH/digestion could prevent indicator regrowth)
Visits and evaluations by DC Water to TH facilities (ten plants) over the past decade
TH projects have progressed successfully to large size/capacity from 1995 to 2010
DC Water has conducted research and field testing at TH/digestion plants to confirm performance and suitability at Blue Plains
Anglian Water’s Cotton Valley Plant, UK
Anaerobic Digestion remains the cornerstone of BMP Least reactor volume and small footprint TH by Cambi proven at large-scale and can be
implemented in USA Produces well-dewatered and high quality product Class A product (diversification) needed long-term
for sustainable program Produces best energy
scenario and GHG reduction Board of Directors of
DC Water approved recommendation in 2008
4/23/2012
8
WERF Award for Excellence in Innovation given at WEFTEC 2011 in Los Angeles
For extensive use of WERF-funded research to attain a new level of biosolids product stability
Awarded to DC Water in collaboration with Brown and Caldwell and Bucknell University
Walter Bailey, PE, BCEE, WEF Fellow Assistant General Manager-Blue Plains
DC Water and Sewer Authority
Thank you!!!
Keith Panter, Ebcor Ltd.
Key Papers:◦ Haug et al 1978 – shows moderate heat treatment
increases digestion rate and improves dewatering◦ Li and Noike 1992 – demonstrates optimum time
and temperature for WAS hydrolysis and benefits Cambi invention 1992 addresses issues of
previous heat treatments ( e.g. Zimpro) and uses the system as a pre-treatment for anaerobic digestion
First plant in Norway 1995 - operating for 17 years now
4/23/2012
9
CAMBI PLANT LOCATIONS
EUROPE
Norway
Poland
Denmark
UK
Ireland
GermanyBelgium
Finland
Plus Niigate, Japan Brisbane, Australia Santiago, Chile Washington DC
Projects developing in China and the Americas
0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
900,000
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
/3
cumulative 37 projects
cumulative capacitytds/year
27 million population equivalent
Optimum temperature about 160º C, 320º F to avoid side-stream issue – pressure cooking not caramelization
Batch process with steam injection (150 psi) -to avoid heat exchangers’ scaling and corrosion
Treats cake and has internal recycle of steam – to reduce energy consumption
Steam pressure drop disintegration – reduces particle size and viscosity for subsequent digestion
Coupling with anaerobic digestion – high solids digestion to make a biosolids for recycling/disposal and improve energy balance. High gas yields at short retention.
PROCESS FLOW – THERMAL HYDROLYSIS PRE-TREATMENT BEFORE ANAEROBIC DIGESTION – “CONTINUOUS/BATCH”
FLASH TANKdisintegration
REACTOR(s) – UP TO 6Batch pressure cooking
PULPERPre-heat tank
Raw sludge cake ~17% DS
homogenised/hygienised sludge
hydrolysedsludge
steam 150 psi
hydrolysed sludge to digestion8-12% DSDilution and cooling needed
Recycled steam forenergy recovery
Process gases (to digester)
4/23/2012
10
Typical Cambi plant for 60 mgd
pulper reactors
Flash tank
Raw cake silo
cooler
Mezzanine with valves
viking
Batch heat sterilization Meets all known safety standards worldwide, USEPA
alternate 1 time/temp Class A batch – no reactivation Destruction of Extra Cellular Polymer – ECP
Sludge becomes compressible for dewatering (10% DS% gain) and less viscous (10% hydrolysed =~ 5% conventional)
Hydrolysis of insoluble COD 30-50% solubilisation enables very rapid digestion, 10
days HRT, 60% VSR Steam disintegration of particulate matter
Increases digestion rate and reduces viscosity further
5. Dewatered biosolids cakeat 30-35%DS
2. Cambi hydrolyzed sludgeat 12-13% DS (pre-dilution)
3. Mix of digested sludge (3/4) and hydrolyzed sludge (1/4)to digester. 7-8% DS
1. Dewatered15-18% DS (before THP) 4. Digested
sludge6% DS
Control parameters ”Cambi” digester Conventional digester
Retention time 10-15 days 20 days
DS% feed 9 – 12% 4 – 6%
Digester Volume < ½ of conventional 1
VS load >5-7 kg/m3/day380-550 lbs/1000 cuft
2-3 kg/m3/day150-250 lbs/1000 cuft
pH 7.5 – 8.0 6.8 --7.5
Temperature 38-42ºC, 100 -108ºF 35-37ºC, 95 -98ºF
VFA / Total alkalinity 0.1- 0.5 0.1- 0.5
Ammonium 2000-3000 mg/l 600-1500 mg/l
Gas quality 62-68% CH4, H2S low 60-65% CH4, H2S high
Foaming bacteria None Nocardia, Microthrix
4/23/2012
11
Operating costs ($10-40/tds) for THP –its all about steam and polymer costs
•Focus on low cost pre-dewatering – aim for 5-6 lbs/tds•Integrate engine waste heat (exhaust gas) with steam production – Cambi system is 20-50% more efficient per tds than other systems due to energy recycle -DC is ~self sufficient in steam due to turbine waste heat•Operates automatically 24/7 with day shift supervision and maintenance in most systems
THP uses 1/3rd of biogas if no cogen
Compact new build digestion e.g. Dublin, DC “Turbo” digestion to create capacity – often
with regional sludge centre e.g. Manchester –and majority of UK plants
100% WAS e.g. Welsh and Danish plants (aerobic digestion conversion?)
WAS only mixed with primary (Class B) for digestion feed at 7% DS e.g. Santiago, Chile (instead of acid phase – dewatering upside)
Moving away from incineration and thermal drying to class A, high solids cake, cogen for
lower costs and GHG footprint
Naestved (DK, 2000) – 8 mgdextended aeration sludge
KAPUSCISKA WWTP, BYDGOSZCZ, POLAND 25 mgd
• 2004: 20,000 tpa cake at 20-23% DS
• 2006: 10,000 tpa Cambi cake 30-33% DS
4/23/2012
12
Keith Panter, Ebcor Ltd.Thank you!!
Perry Schafer, PE, BCEE, Brown and CaldwellDC Water Biosolids Management Team
April 25, 2012
Program development to Preliminary Design level by the Biosolids Program Manager
Thermal hydrolysis/digestion – challenges and innovations
Procurement issues for TH/digestion at Blue Plains
48
Existing Solids Processing Area - Class B Lime Stabilization
New Biosolids Program Site (7 acres)
4/23/2012
13
System and PeakingLime StabilizationAverage AnnualPeak MonthPeak Week and Greater
TH-DigestionAverage AnnualPeak MonthPeak Week and Greater
2012-Existing
340400-450400-450*
000
2015-New System
BackupBackup
Up to 350
380450500
* Higher production peaks are stored within existing processes. Dewatering
Lime
Store &Loadout
Class B
DAFTs
Mix
R
R
Screening and Pre-Dewatering
FinalDewatering
RecycleProcessing
R
LoadoutCambi™ THP
Steam Biogas
Biogas Treatment and CHP
Emissions
MesophilicAnaerobicDigestion
Class A
Power
R
R
GravityThickeners
Blend Tank
50
Cake product will be ~30 % solids, stable, screened, Class A
The Plan: Continued land application-
initial focus Develop and maximize
marketable products starting in 2015
Further processing likely, including blending materials with Class A cake
Under Chris Peot’s leadership at DC Water
51
TH/digested cake land application at Aberdeen, Scotland
VS loading at 0.4+ lb VS/ft3/day
Only 15 MG of Digesters, Rather than 40+MG required for typical MAD
At $5/gal = $125+ million savings and much less space required
0
1
2
3
4
DC Water Digesters
Typical Sludge Digestion
Ft3 biogas/day
Ft3 of tankage
Feeding ~10% Solids
4/23/2012
14
Taller tanks for capacity, mixing, and saves space
Optional concrete construction methods for price competition
DC Water tanks are 3.8 MG each(~95ft Ø by 70+ ft SWD)
Continuous Normal Surface Overflow
Backup and Emergency Overflows
Continuous Bottom Withdrawal
Tank Headspace
Typical Draft Tube MixingSystem
5 per Tank
MotorGas Takeoff
Four CambiTHPTrains
Typically 80 - 90° C Thermally Hydrolyzed Solids
Cooling HEXs Digesters
= Control Valve with Flow Meter
Higher pressure
portion of feed loop
Documented events of rapid liquid level rise (gas holdup)
Highly-loaded, tall digesters with thick solids increase the risk
Control measures include continuous feed, controlled DTM mixing, extra freeboard, huge overflow capacity, and overflow storage
Overpressure damaged fixed cover digester
Cake drops directly into cake bins
Pre-dewatered cake pumped minimum distance to THP trains
Final Dewatering (BFP) cake-single belt conveyor to loadout
15 to 18%Solids
Pre-Dewatering Centrifuges
PC Pump to Cambi THP
Cake Bin
4/23/2012
15
Detailed business case evaluation of BFPs vs. centrifuges
Both technologies achieve ~30% solids
BFPs use less energy Net present value of options was
similar - space requirements also similar
No regrowth with either, but odor regrowth potential with centrifuge
BFP pilot testing in U.K. on Cambi/digested feed – to determine parameters for design
0
5
10
15
20
25
30
35
Cak
e S
olid
s (%
)
Belt Filter PressDewatering
CentrifugeDewatering
1 2 3 43 5 6 3 3 7 8
THP Site
Centrifuge Dewatering
Belt Filter Press
Dewatering
THP Site
Ca
ke S
olid
s (%
)
Power toBlue Plains AWTP
Maximize power production and meet steam needs of Cambi THP
12 bar (175 psi) steam
73 % overall power/heat efficiency
Low-NOx emissions from Solar Mercury 50 gas turbine
Flexible operation to meet peak steam needs
3 Turbine/HRSG system is being installed: ~13 MW total power, ~10 MW net power
HRSG
Duct Burner
Steam to Cambi THP
Gas Turbine(Solar Mercury 50)
Generator
CombustionAir
DigesterGas Compressor
Gas
Supplemental Natural Gas
Exhaust Gas
Single point responsibility for design and construction
Schedule advantages Ability to share risks
appropriately Earlier price determination Tunnel project decision was
already made-DB TH projects typically procured
overseas via DB
DB
A decade of TH evaluation, site visits and R&D work, resulted in sole-source decision in 2009
Determined that Cambi’s THP was the only TH system proven at the scale required for Blue Plains
DC Water then contracted with Cambi to define the interfaces for Blue Plains
Cambi THP – 4 Train System for DC Water
4/23/2012
16
61
MesophilicDigestion
Workshops to assess risks Market surveys of potential DB contractors Discussions with TH owners in UK/Europe Examined experience of other large vendor systems within
major project procurement
62
Conclusion: DC Water/Program Management developed Term Sheet for Cambi THP (scope/price/key terms established). Term Sheet expanded to Cambi subcontract by winning DB Team
Screening and Pre-Dewatering
Cambi THP
Main Process Train
Prescriptive RFP to insure facilities will “fit” and provide high-quality equipment/system
For critical equipment, specific vendors were named
Over 30 Performance Guarantees/Acceptance Tests were defined: capacity, performance, permit-related
Limited Technical Alternatives were allowed within the proposal process
6 SOQs received, then short-listed to 3 for proposals with price/technical evaluation. Successful DB procurement process
Main Process Train
MesophilicDigestion
Screening and Pre-Dewatering
Cambi THP
64
Dewatering
Lime
Store &Loadout
Class B
Mix
R
R
Screening and Pre-Dewatering
FinalDewatering
RecycleProcessing
R
LoadoutCambi™ THP
Steam Biogas
Biogas Treatment and CHP
Emissions
MesophilicAnaerobicDigestion
Class A
Power
R
R
GravityThickeners
Site Preparation
DBO DBB
DBB
DB
Blend Tank
DAFTs
4/23/2012
17
66
Perry Schafer, PE, BCEE, Brown and CaldwellDC Water Biosolids Management Team
April 25, 2012
Peter Loomis, PEDave Parry, PE, PhD, BCEE
CDM Smith
April 25, 2011
4/23/2012
18
Program Approach Project Approach Project Team Design
Requirements Design Issues &
Resolutions Summary
Solids Screening Building
Odor Control Towers Thermal
Hydrolysis Process (Cambi)
DigestersPreDewatering Building
Enclosed Flares
Combined Heat and Power Facilities (Not in MPT Project)
Digester Building
Existing Buildings
ThermalHydrolysis Cooling HEX
Tuning HEXDilutionWater
Pre-DewateringScreening
Pre-Dewatering
Building
DigestersThermal Hydrolysis
(Cambi) Process
4/23/2012
19
B&CArcadis
PC/CDM Smith Joint Venture,
Cambi
DC Water
OVERALL PROJECT MANAGER
DESIGN PROJECT MANAGERPERMIT MANAGERCONSTRUCTION PROJECT
DIRECTORCOMMISSIONING MANAGER
Design/build RFP/Contract with
design concepts DC Water design and
construction standards apply
Prescriptive Firm fixed price Cambi and Emerson as
required suppliers
Throughput of 450 dtpd firm capacity
Expandable to 675 dtpd Feed sludge is mix of
TPS & TWAS and highly variable
Class A biosolids produced
33 Process Guarantees in the Contract
4/23/2012
20
Digester building located underground
Concurrent installation of piles for all structures
Allows early mobilization of mechanical installers
Saves time and increases DC Water savings
Solids Blending Tanks Sludge Screening Pre-Dewatering Dewatered Sludge Storage and Pumping Thermal Hydrolysis (Cambi) Biosolids Cooling Digestion Digested Biosolids Transfer & Holding
Sludge Conditioning for THP
Sludge Viscosity post-THP
Biosolids Cooling Rapid Rise Event
Contingencies Gas Production Condensate Control
Screening required to 5 mm◦ Reduces wear on THP
components◦ Reduces risk of pressure vessel
failure◦ Increased life of pump stators
Dewatering to 15% to 18% DS (>16.5% avg)◦ Design basis for Cambi
throughput is 16.5% DS◦ Optimize processing time
4/23/2012
21
Preliminary work done by Dr. Matt Higgins
Thermal hydrolysis greatly reduces apparent viscosity
Digestion after THP further reduces apparent viscosity
Rheology similar to sludges at 1.7 to 1.9x concentrations
0.0010
0.010
0.10
1.0
10
0.1 1 10 100
2.0% MAD2.9% MAD3.6% MAD3.9% MAD3.9% Cambi-MAD5.5% Cambi-MAD6.1% Cambi-MAD
App
aren
t Vis
cosi
ty (P
a-s)
Shear Rate (1/s)
Max inlet T = 112.7°F Cooling water max inlet T = 81°F Discharge T = 100°F Velocity = 6.5 fps Viscosity = 20 cP to 35 cP
Hydrolyzed biosolids exit THP at up to 194°
Cooling sources◦ Dilution water◦ Solids blending◦ Tube-in-tube heat exchangers
Contract Requirement is 9.6 MMBtu/Hr per digester
Tuning HEX also at 1.3 MMBtu/hr per digester
4/23/2012
22
Freeboard in each digester Overflow wetwell (shared
between each pair of digesters)
Total storage is 400,000 gallons each digester
Additional standpipe storage allows overflow rate of 24,000 gpm
Mixers are bi-directional Considering standby power
for 2 mixers per digester
Hydrolyzed sludge biodegrades at a higher rate
Expect 55% VS removal (40% typical for MAD)
No gas storage other than headspace
Digester gas pressure 50% higher than typical (18” w.c.vs. 12” w.c.)
Significant H2S not expected due to high ferric dosing in liquids train
Condensate collection for each digester◦ Higher gas production◦ No gas storage◦ Reduces risk of plugging
Sideline condensate collection◦ Lower headloss◦ Minimizes plugging from foam
Project D/B team and approach
Benefits of 3D/4D Construction sequence Design details◦ Dewatering, screening◦ Cooling◦ Rapid rise◦ Biogas management◦ Condensate control
4/23/2012
23
Peter Loomis, [email protected] Parry, PE, PhD, BCEE
CDM SmithThank you!!!
“Thermal Hydrolysis Comes to America: DC Water’s Blue Plains Digestion Project”
Q & A Session