Ohio Water Environment Association December 3, 2015 Biosolids Workshop. Southerly Renewable Energy Facility

Transcription

1 Ohio Water Environment Association December 3, 2015 Biosolids Workshop Southerly Renewable Energy Facility

2 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

3 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

4 Skimmings Biosolids Skimmings NEORSD Wastewater Treatment Plants Westerly Avg: 26 MGD Easterly Avg: 94 MGD Biosolids Force Main Pumps 1.3 billion gallons of wastewater solids to Southerly each year for processing and disposal Largest WWTP in Ohio. Can treat up to 736 MGD. Southerly Avg: 126 MGD 4

5 WWTPs, Service Areas, Major Sewers E W S

6 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

7 Biosolids Handling Before REF DPS Sludge Storage Gravity Thickening NORTH To Ash Lagoons TCSTs MHIs Dewatering Zimpro Gravity Belts EAS

8 Southerly Biosolids Handling (before REF) Thermal Conditioning System (Zimpro) produced Class A biosolids; 5 equipment trains psig; ºF; gpm 4 Thermally Conditioned Sludge Thickeners 6 Humboldt 53 DTPD High Solids Centrifuges ~ 47% solids 4 Multiple Hearth Incinerators 3.6 DTPH permitted feed rate; 2.7 DTPH actual capacity 4 Waste Heat Boilers produce 425 psi HP steam, primarily for Zimpro

9 Biosolids Handling After REF To Ash Lagoons DPS Renewable Energy Facility Sludge Storage Gravity Thickening NORTH Gravity Belts EAS

10 Facilities Decommissioned After REF Also Decommissioned: Skimmings-only FBI at Easterly WWTP NORTH GRAVITY BELT THICKENERS HUB, OFFICES 2 VCUs ZIMPRO 2 VCUs DEWATERING & CONVEYANCE MHIs WASTE HEAT BOILERS THERMALLY CONDITIONED SLUDGE THICKENERS 2 VCUs Site of REF MAINT. BLDG. SLUDGE STORAGE TANKS DIGESTER TANKS

11 Renewable Energy Facility Layout NORTH Hub, Offices Dewatering Incineration Substation, MCC Turbine Generator Bldg. Truck Loading

12 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

13 Biosolids Production After Zimpro Decommissioning Average biosolids production was projected to increase by about 40% because volatile solids would no longer be thermally destroyed. Actual increase is probably closer to 20%. %TVS with Zimpro ranged between 41 and 69 with an average of 58. From Jan. 1, 2015 through Sept. 30, 2015, %TVS (without Zimpro) ranged between 52.6% and 80.1% with an average of 65.5%.

14 Biosolids Incinerated Per Year (DT) The annual avg. for is 20% greater than the annual avg. for

15 Anticipated Characteristics of Dewatered Biosolids Pumped to FBIs Parameter Chemically Conditioned (Polymer) Design Total Solids (%) 28 Total Solids Range (%) Design Volatile Solids (% VS) 68 Volatile Solids Range (% VS) Design Higher Heating Value (Btu/lb VS) 10,500 Higher Heating Value Range (Btu/lb VS) 9,500-12,000

16 2015 Monthly Averages - %TS & %TVS 68% 28%

17 BTU/lb VS during Stack Tests 10,243

18 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

19 Renewable Energy Facility What s inside? The 50,600 SF multi-story REF Building houses the following new systems: Three 100 DTPD Infilco Degremont FBIs; FBIs process Southerly and Easterly WWTP biosolids and skimmings from all 3 WWTPs Biosolids dewatering and conveyance: three Andritz 50 DTPD high solids centrifuges, one 32 CY receiving bin and two Schwing 50 DTPD dual piston pumps per FBI Steam produced by waste heat boilers in FBI trains turn Elliot turbine generator to produce electricity (2-3.5 MW)

20 Dewatering & Conveyance

21 Skimmings Skimmings (1-2 gpm typ.)

22 HMI Screen Capture for FBI Train

23 Incineration System Process Flow Diagram 1550 F Steam 300 F 1550 F Freeboard 1075 F 700 F 635 psig 350 F 1375 F 1200 F 425 F Natural Gas Biosolids Natural Gas Sand Bed Hot Wind box Waste Heat Boiler 200 F Fluidized Bed Incinerator 100 F Fluidizing Air Blower Boiler Feed Water Induced Draft Fan 125 F

24 Incineration System Plan View (Typ. of 3) PHX FBI WHB SHX WSC IDF

25 Fluidized Air Blower FBI PHX

26 Fluidized Bed Incinerator

27 Fluidized Bed Incinerator Roof Sprays 6 Ports Upper Freeboard Refractory Dome Biosolids, Skimmings 4 Ports Lower Freeboard Natural Gas 20 Ports Fluidizing Air Windbox

28 Primary Heat Exchanger Exhaust Gas from FBI Heated Fluidizing Air to FBI Windbox Fluidizing Air from FAB Exhaust Gas to WHB

29 Waste Heat Boiler Steam Drum Exhaust Duct on Economizer Waste Heat Boiler

30 Waste Heat Boiler Steam Drum Economizer

31 Secondary Heat Exchanger Scrubbed Gas from IDF Scrubbed Gas to Stack Exhaust Gas To WSC Exhaust Gas from WHB

32 Wet Scrubber Exhaust Gas From SHX Scrubbed Gas To IDF Wet Scrubber Pre-Cooler

33 Induced Draft Fan Scrubbed Gas from WSC Scrubbed Gas To SHX Pre-Cooler Stack

34 Monthly Operating Data for 2015 Total Dec Nov Oct Sept Aug July June May April March Feb Jan FBI FBI FBI Operating Operating Operating Number of days with 0 FBIs in operation: 1 (2/11/15) Number of days with 1 FBI in Operation: 44 (16% of the time) 3, DT processed; DT/day/FBI Number of days with 2 FBIs in operation: 227 (83% of the time) 27, DT processed; DT/day/FBI Number of days with 3 FBIs in operation: 1

35 Dry Tons per Day During 2015 (Monthly Avg.) December November October September August July June May April March February January FBI FBI FBI

36 Hours of Autogenous Operation Per Month During 2015 Total Dec Nov Oct Sept Aug July June May April March Feb Jan FBI FBI FBI ,206 Best performance by a single FBI: 93 hours of autogenous operation for FBI 3 over a 96 hour period on April 9-12, 2015 ~ DT processed; DT/day; %TVS = to Best performance of two FBIs concurrently: 23 hours of autogenous operation for FBIs 1 & 3 on September 27, ~ DT to FBI 1; DT to FBI 3; %TVS = No. of calendar days FBIs operated autogenously: 16 ~ FBI 1-0 days; FBI 2-4 days; FBI 3-12 days No. of calendar days FBIs operated autogenously for at least 12 hrs/day: 86 ~ FBI 1-11 days; FBI 2-26 days; FBI 3-49 days

37 600,000 Total Gas Usage at SWWTC in MCF 200,000 $5.30/MCF = $1.06 Million in annual savings 500, , , , ,

38 1.86 MCF

39 Comparison of MHI & FBI Emissions Year Type of Incineration Tons of Pollutants* Dry Tons of Biosolids 2010 MHI , MHI , MHI , MHI , MHI & FBI , (Jan. Sept.) 2015 (12 month est.) FBI ,469 FBI ,959 * Summation of the following pollutants: CO, NO x, SO 2, PM f, OC & Pb. For the FBIs, its VOC instead of OC, and PM f plus PM c instead of PM f.

40 Comparing FBI and MHI Emission Factors (in lbs/dt) Pollutant FBI 1 Emission Factors (9/23/14) FBI 2 Emission Factors (9/3/14) FBI Emission Factors (10/7/14) Avg. Emission Factors for the 4 MHIs CO NO x SO PM f PM c VOC Pb

41 2015 Southerly FBI Emissions (Jan. 1 through Sept. 30) Pollutant Tons for FBI 1 Tons for FBI 2 Tons for FBI 3 Tons for all FBIs CO NO x SO PM f PM c VOC Pb Totals DT of Biosolids 7,895 12,010 11,564 31,469

42 Air Pollution Permit-to-Install Original 2008 PTI contained the following requirements which where deleted in 2014 and 2015 revisions FBIs shall incinerate no more than 82,500 DT of biosolids annually FBIs shall consume no more than 100,000 MCF of natural gas annually All other requirements of the PTI are being met

43 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

44 Energy Production by the Steam Turbine Generator The steam turbine generator is designed to work in conjunction with two FBIs. If the third FBI is in operation, excess steam will be directed to the auxiliary condenser The steam turbine generator can produce up to 3.5 MW, but is currently producing 1.25 MW. At $0.066/KWH, the retail cost of this power is $1,980 daily, and $722,700 annually The power produced by the steam turbine generator is fed to Substation 21, the main substation for the REF The REF uses 6 to 8 MW on average The entire Southerly WWTC used 11.1 MW on average in 2015 (monthly averages in 2015 have ranged from 10.3 MW to 11.8 MW).

45 CONDENSATE TANK Steam System For Power Generation Process Flow Diagram WHB DEAERATOR CONDENSATE SUPPLY PUMPS BOILER FEED WATER PUMPS AUXILIARY CONDENSER MAKE UP WATER STORAGE TANK MAKE UP WATER PUMPS STEAM TURBINE MAIN CONDENSATE PUMPS GEN MAIN CONDENSER AUXILIARY CONDENSATE PUMPS HEAT EXCHANGERS COOLING WATER PUMPS Additional deaerator and boiler feed water pump being installed to improve redundancy

46 Energy Production Turbine Generator Main Condenser Auxiliary Condenser

47 Agenda Introduction to Southerly WWTC Biosolids Handling Before & After REF Changes in Biosolids FBI Performance Energy Production Future Improvements

48 40 CFR Part 60 Subpart LLLL Emission Limits for FBIs Pollutant Units Limit FBI 1 FBI 2 FBI 3 PM mg/dscm 18 Y Y Y HCl ppmvd 0.51 Y Y Y CO ppmvd 64 Y Y Y Dioxans/ furans TEQ ng/dscm 0.10 Y Y Y Hg mg/dscm N N Y NO x ppmvd 150 Y Y Y SO 2 ppmvd 15 N N N Cd mg/dscm Y Y Y Pb mg/dscm Y Y Y Compliance required by March 21, 2016!

49 Envirocare Mercury Scrubber (installed on top of existing wet scrubbers) Sorbent Polymer Composite

50 Sorbent Polymer Composite (W. L. Gore of Gore-Tex fame) Guaranteed to meet FBI emission limits for Cd, HCl, Hg, Pb, PM and SO x with the following conditions: Cd concentration 4.7 mg/kg in dry biosolids Pb concentration 140 mg/kg in dry biosolids Sulfur concentration 0.9% in dry biosolids PM concentration 10 7% dry O 2 at mercury scrubber inlet Hg concentration % dry O 2 at mercury scrubber inlet

51 So In Conclusion Biosolids Production is up 20% due to Zimpro decommissioning; a desired %TS easy to maintain; %TVS affected by factors beyond our control Autogenous operation is not the norm, but gas usage is down significantly, and Operations will continue to improve FBI performance FBI emissions are 26% of MHI emissions; mercury scrubber will further decrease emissions to meet new SSI standards Steam turbine generator is routinely in operation and producing electricity for REF; Operations will continue to improve performance and increase MW

52 Questions?