8. Biogas Production Summary (SW + AW Flow)
Year
Sludge TSS
Loading
(lb/day)
Average
Biogas
Produced
(ft3
/day)
Max Month
Biogas
Produced
(ft3
/day)
Average
Heat from
biogas
(MMBtu/hr)
2013 28,960 203,000 294,698 4.7
2023 31,150 216,000 334,868 5.0
2033 33,510 231,000 357,900 5.4
Average: 31,000 220,000 340,000 5
8
5% total growth of both raw and digested solids over 10 years
20 year design period
9. 9
Parameter AVG MAX
Thermophilic Tank (ºF) 131
Ambient to Thermophilic (ΔºF) Δ57 Δ77
Sludge to Thermophilic (ΔºF) Δ72 Δ77
Sludge Influent (GPD) 73,000 113,000
Heat Required (MMBtu/hr) 1.4 2.4
NOAA: Ambient Temperature 74ºF (Average), 54ºF (Low)
24. 24
Juan Oquendo, P.E.Juan Oquendo, P.E.
Group Mentor
Senior Environmental Engineer
Gresham, Smith and Partners
Sarina Ergas, Ph.D., P.E.Sarina Ergas, Ph.D., P.E.
Associate Professor
Civil and Environmental Engineering
University of South Florida
Tom Cross, P.E.Tom Cross, P.E.
Visiting Professor
Project Manager
McKim and Creed
25. 25
Margaret ConeMargaret Cone
margaretcone@mail.usf.edu
Matthew WoodhamMatthew Woodham
mwoodham@mail.usf.edu
Melissa ButcherMelissa Butcher
mbutcher@mail.usf.edu
Nicole SmithNicole Smith
ncsmith@mail.usf.edu
George DickGeorge Dick
georgedick@mail.usf.edu
26. Brown and Caldwell. (2011). “Evaluation of WRF Sludge Consolidation/Conveyance
Options.” Draft technical memorandum to the City of St. Petersburg on City Project
No. 09027-121, Brown and Caldwell, Tampa, FL.
2G-CENERGY. (2010). “2G A500 BG Twin-Pack® – 500ekW.” 2G-CENERGY,
<http://www.2g-cenergy.com/specsheets> (Apr. 11, 2013).
Capstone. (2013). “Turning Waste Into Power.” Photo available from
<http://www.capstoneturbine.com/prodsol/solutions/rrbiogas.asp> (Mar. 28, 2013)
CDL Life. (2012). “CNG Fuel Station Sites Will Double Capacity in 2016.” Photo
available from <http://cdllife.com/2012/technology> (Mar. 28, 2013)
Global Sources. (2013). “CNG Gas Station.” Photo available from
<http://p.globalsources.com/IMAGES/PDT/T1044903160/CNG-Gas-
Station.jpg>
(Mar. 28, 2013)
26
31. 31
Item Description Units Quantity Unit Price Total
Boiler Equipment
8'' Stainless Steel 316L, Schedule 40 Pipe LF 130 $109 $14,200
Biogas Purification Unit (Iron Sponge)
LS 1 $90,000 $90,000
Electricity & Instrumentation % 15 - $15,600
Installation % 60 - $71,880
Subtotal $191,680
Contractor (15%) $28,752
Subtotal $220,000
Contingency (30%) $66,000
SUBTOTAL $286,000
Engineering/Admin (30%) $86,000
TOTAL CONSTRUCTION COST $370,000
32. 32
Item Description Units Quantity Unit Price Total
Energy Savings
Natural Gas (TECO) Therm 14,600 $0.37 $5,400
Operation and Maintenance
Boiler (gaskets, inspection, cleaning) LS 1 -$170 -$170
Iron Sponge (media replacement, etc.) LS 2 -$150 -$300
Subtotal $4,900
Contingency (30%) -$1,470
NET MONTHLY SAVINGS $3,400
33. 33
Item Description Units Quantity Unit Price Total
Equipment
250kW ICE Twin Pack kW 500 $1,200 $600,000
Hot Water 6'' CPVC LF 100 $3 $300
Pump LS 1 $3,000 $3,000
8'' Stainless Steel 316L, Schedule 40 Pipe LF 130 $109 $14,200
Biogas Conditioning Equipment LS 1 $200,000 $200,000
Electricity & Instrumentation % 15 - $123,000
Installation % 60 - $204,300
Subtotal $1,145,000
Contractor (15%) $171,750
Subtotal $1,320,000
Contingency (30%) $400,000
SUBTOTAL $1,720,000
Engineering/Admin(30%) $520,000
TOTAL CONSTRUCTION COST $2,200,000
34. 34
Item Description Units Quantity Unit Price Total
Energy Savings
Electricity kWh 310,000 $0.0916 $28,400
Demand kW 425 $4.83 $2,100
Natural Gas Therm 14,600 $0.37 $5,400
Operation and Maintenance
250kW ICE kWh 310,000 -$0.01 -$3,100
Biogas Conditioning System Therm 32,000 -$0.08 -$2,600
Subtotal $30,000
Contingency (30%) -$9,000
NET MONTHLY SAVINGS $21,000
35. 35
Item Description Units Quantity Unit Price Total
Equipment
Fill Station at SWWRF LS 1 $500,000 $500,000
Fill Station at Sanitation LS 1 $500,000 $500,000
Biogas Conditioning and Upgrading LS 1 $2,013,000 $2,013,000
Electricity & Instrumentation % 15 - $452,000
Installation % 60 - $2,079,000
Tube Trailers LS 4 $350,000 $1,400,000
Subtotal $6,944,000
Contractor (15%) $1,042,000
Subtotal $7,986,000
Contingency (30%) $2,400,000
Subtotal $10,390,000
Engineering/Admin (30%) $3,120,000
TOTAL CONSTRUCTION COST $14,000,000
36. 36
Item Description Units Quantity Unit Price Total
Energy
Natural Gas to Fleet Vehicles Therm 32,000 $0.995 $31,800
Operation and Maintenance
Fill Stations LS 2 -$2,500 -$5,000
Biogas Upgrade (PSA) Therm 32,000 -$0.39 -$12,000
Diesel Fuel for Semi Truck Gal 60 -$4.00 -$240
Compression Therm 32,000 -$0.20 -$6,400
Boiler (gaskets, inspection, cleaning) LS 1 -$170 -$170
Biogas Conditioning Therm 32,000 -$0.16 -$5,120
Insurance LS 1 $7,500 -$7,500
Subtotal -$4,630
Contingency (30%) -$1,389
NET MONTHLY SAVINGS -$6,000
37. 37
Sample of a rotation schedule for tube trailers:
Trailer # Fri Sat Sun Mon Tues Wed Thurs Fri Sat Sun
TT 1 F-1200 F 300 W R 1500 W F 1200
F 300
R 300 W W
R 1200
TT 2 W F 900 F 600 R 300 R 1200 W F 900
F 600
R 400 W
R 550
TT 3 W W F 600 F 900 R 600 R 900 W F 600 F 900 W
TT 4 W W W F 300 F 1200 R 900 R 600 W F 300 F 1200
Total fill 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200
Total
release
0 0 0 1800 1800 1800 1800 850 400 0
F - Fill
R - Release
W - Wait
41. PrimeMover
CoreEngineType
Configuration
Arrangement/ Cylinders
Displacement/ BHP
CompressionRatio
2xMAN® 2G®A306
E2876LE302ccccccccc
2G® BiogasOptimized
2xIL6
12.8L/ 351BHP
14.8:1
-designed,
and post-
Module,
on-ready”.
acilities in
market.
equipment
h state-of-
mance and
generation
rts energy
nic engine
at provides
ncy. Items
izing and
gine jacket
echnology
2G2Gtwintwin--packpack®® ––500ekW500ekWBiogasBiogas
CHPCogenerationModuleCHPCogenerationModule
LeanCombustionTechnologyLeanCombustionTechnology
®
TWINPACK
41
PrimeMover
CoreEngineType
Configuration
Arrangement/ Cylinders
Displacement/ BHP
CompressionRatio
Speed
Frequency/ Phase
Voltage*
Electrical Output
ThermalOutput
CombinedOutput
ThermalHeat BTU
Ø WaterFlowHT
Hot WaterFlowLT
WaterTemperature
Electrical Efficiency
ThermalEfficiency
Total Efficiency
Consumptionm³/h
Consumptioncf/h
Consumptioncf/m
Cons. BTU/ ekW
ExhaustGasMass(Wet)
ExhaustGasVolume
2xMAN® 2G®A306
E2876LE302ccccccccc
2G® BiogasOptimized
2xIL6
12.8L/ 351BHP
14.8:1
1800RPM
60Hz/ 3-Phase
480V
500ekWcontinuous
626kWcontinuous
1126kWcontinuous
2,136,000(usable)
17,330gph/ 65,602L/h
8,454gph/ 32,000L/h
90°C/ 194°F
39.10%
45.90%
85.00%
221.8m³/h
7,846ft³/h
130.76ft³/m
8,789
2x1,140kg/ 2,514lbs
2x1,003m³/h/ 35,420ft³/h
efficiency. The 2G® CHP module integrates all cogeneration
components into one unique package that converts energy
more efficiently than conventional CHP systems.
The robust design utilizes full authority electronic engine
management, incl. CHP performance monitoring that provides
prolonged life, low maintenance, and high efficiency. Items
such as, engine & system controls, synchronizing and
paralleling switchgear, heat recovery (both for engine jacket
water and exhaust), the entire thermal heat technology
system, pumps, piping, plumbing, etc., are all included “within
the module” dramatically reducing the risk of cost overruns
and performance issues associated with conventional “site
built” systems.
The 2G® CHP module allows for optimized efficiency by
maximizing heat recovery and applying a more efficient
combustion technology, leading to a higher electrical
output.
ExtremelyDurableDesign EasyServiceAccess
(*OtherVoltagesareavailable).
®
Twin-PackContainer - Compact &SmallFoot-Print
TWINPACK
42. Main Control Module
STANDARDEQUIPMENTINCLUDED:
GEMisequippedwithafullyintegratedelectronicG
Control (Speed&LoadSharing, kW /kVAR) consist
Actuator
SpeedSensing&Control
3-PhaseMonitoringof Voltage&Current
LoadSensor
LoadManagement
RampGenerator for RampTimeandIdle
Power FunctionRegulation
VoltageRegulator Sensing&Control
Select Switchfor Isochronousor DroopMode
Controlsfor “RatedSpeed, Stability, Gain, Ramp
LowIdleSpeed, LoadGain, Droop, De-Droop”
Rheostat for Control of Speedfor Synchronization
MultipleProcessControl Features:
Space Ventilation, Ambient Air & Temperature, P
Volumes, Communication Interface with Digester
SupplyControls, GasTreatment, andmuchmore.
CHPControl System&SwitchCHPControl System&Switch
Digital 2GDigital 2G®® GEMGEM
General ElectronicManagemeGeneral ElectronicManageme
42
Main Control Module
NEMA Enclosure incl. separate CB Containment
Touch Screen (Multi Language Select Capability)
Gas & Air Mixing / Air – Fuel Ratio Management
Throttle Control & Gas Flow Regulation
Continuous Engine & Generator Measurements
Continuous Gas Fuel Process Measurements
Continuous Measurement of Exhaust, Cooling System (Mixture
& Dump Cooler), and Thermal Heat Distribution
Data Link – I/O Controller Technology
Complete Synchronization & Interconnection Control
The GEM Control & Switchgear is designed “plug-and-play”
reducing the time and effort required to integrate system
components. The universal connection standards greatly
STANDARDEQUIPMENTINCLUDED:
GEMisequippedwithafullyintegratedelectronicGovernor
Control (Speed&LoadSharing, kW /kVAR) consistingof:
Actuator
SpeedSensing&Control
3-PhaseMonitoringof Voltage&Current
LoadSensor
LoadManagement
RampGenerator for RampTimeandIdle
Power FunctionRegulation
VoltageRegulator Sensing&Control
Select Switchfor Isochronousor DroopMode
Controlsfor “RatedSpeed, Stability, Gain, RampTime,
LowIdleSpeed, LoadGain, Droop, De-Droop”
Rheostat for Control of Speedfor Synchronization
CHPControl System&SwitchgearCHPControl System&Switchgear
Digital 2GDigital 2G®® GEMGEM
General ElectronicManagementGeneral ElectronicManagement
Nicole [1 min] Good evening, we are NGM3 and we worked on the Biogas Utilization Project for the City of St. Petersburg at their SWWRF. I am Nicole Smith, the project manager and these are my All-Star teammates: this is George Dick, he designed the fleet vehicle and micro-turbine alternatives, Matthew Woodham designed the internal combustion engine alternative, Margaret Cone designed the boiler, and Melissa Butcher did permiting and editing for the group.
The highlight of this presentation is the preliminary design, but before that we will give some background on the current and anticipated treatment processes, the design parameters that we calculated, and then we ’ll review our project objectives and the conceptual design of our main alternatives followed by their evaluations. We will present the preliminary design based on the recommendation from the overall evaluation scores.
Melissa, see my edits in underlined italics. –Nicole The City has four water reclamation facilities. The focus of the Biogas Utilization Project was the Southwest and Albert Whitted Water Reclamation Facilities. The Albert Whitted has been operating at 50% of its permitted influent capacity. Therefore, the City plans to decommission the Albert Whitted facility and divert flow to the SWWRF. With the flows combined, Southwest will remain below its permitted capacity of 20 Million gallons per day and sludge production will increase .
Melissa This schematic depicts the current treatment process at the Southwest facility. This is an advanced secondary wastewater treatment facility that does not have primary clarification. The liquid treatment process goes through screening, de-gritting, biological secondary treatment, secondary clarification, then goes to filtration, and chlorination while Waste Activated Sludge from secondary clarifiers is stored in a sludge holding tank, dewatered by belt press, lime stabilized, and then transported for land application. (click for highlight) The mesophilic anaerobic digesters have deteriorated and have been decommissioned. There are also old aeration tanks and clarifiers that will be demolished with the 2 old mesophilic digesters. To replace the old sludge treatment process, the City ’s consultant has proposed this system for the plant. Sludge from Primary and Secondary clarification will be treated in a Temperature Phased Anaerobic Digestion system (also called TPAD system). Secondary sludge will be thickened in the gravity belt thickener before entering the main thermophilic digester. From here, all sludge will proceed to thermophilic batch tanks then to the mesophilic digester for final stabilization.
Melissa To replace the old sludge treatment process, the City ’s consultant has proposed this system for the facility. Sludge from Primary and Secondary clarification will be treated in a Temperature Phased Anaerobic Digestion system (also called a TPAD system). Secondary sludge will be thickened in the gravity belt thickener before entering the main thermophilic digester. From here, all sludge will proceed to thermophilic batch tanks then to the mesophilic digester for final stabilization. We assumed that this will be the existing system when our biogas utilization design is implemented. Therefore, we only considered the equipment expenses that are outside this pre-biogas-utilization system.
Melissa Anaerobic digestion produces biogas and we can expect a TPAD system to produce nearly 20% more biogas than a standard mesophilic system. Biogas is composed of approximately 60% methane, 35% Carbon Dioxide and 5% of moisture and other constituents. Depending on the end use of the biogas, treatment will be needed to remove moisture, hydrogen sulfide, and siloxanes because they can cause corrosion. For example, siloxanes caused Glendale Water Reclamation Facility in Lakeland to shut down their internal combustion engine and Howard Curren ’s lack of biogas treatment has resulted in a lots of downtime, frustration, and now they are planning to take their engines offline. Also, for our calculations, we used a lower heating value of 560 Btu per cubic foot of biogas – which is a typical value and is comparable to approximately 1000 Btu per cubic foot of natural gas .
Melissa [1 minute] The City initiated this Project with NGM3 to investigate biogas utilization alternatives and determine the most feasible alternative with the best financial return. We completed calculations for projected biogas production and heating requirements for the future digester tanks. These calculations allowed us to move forward with the evaluation of each alternative. Based on our client’s weighted criteria, we determined the optimal alternative and then produced the preliminary design.
Matthew [1 minute] These were used to size the engines in our alternatives. To design our alternatives, we calculated the biogas production we can expect from the combined Southwest and Albert Whitted flows. We did this using a 5% total growth of solids every 10 years for our 20 year design period. Sludge loading was determined based on influent BOD and TSS concentrations. Our average sludge loading over the 20 years is 31,000 pounds per day, which gave us an average biogas production of 220,000 cubic feet per day and a Max Monthly rate of 340,000 cubic feet per day. Our heat from biogas was calculated as 5 million Btu per hour based on the average production rate and used in our energy balances.
Matthew [1 minute] We calculated the expected TPAD heating requirements because of the possibility that biogas can fuel a system to heat digesters. Assuming a typical temperature for the sludge in the thermophilic tank, we calculated the increase in temperature necessary to account for heat loss and the heat needed to raise the sludge temperature from 59 degrees Fahrenheit (15 degrees C). With a sludge influent of 73,000 gallons per day, the average heat required would be 1.4 MMBtu/hr and a maximum of 2.4 MMBtu/hr. These are conservative numbers, and it ’s possible for the digesters to maintain their own temperature due to the chemical process in anaerobic digestion. Having said this, the average heating requirement was used in design to ensure meeting the maximum requirement.
George [1 minute] A foundational assumption for this project is that an alternative will be added to a pre-utilization system. This system I identified earlier as the TPAD system, which we assumed would be heated by boiler fueled by natural gas, while biogas is flared. We investigated three types of biogas utilization including: digester heating, producing electricity and heat with combined heat and power technologies, and removing impurities to upgrade the biogas to renewable natural gas that can then be used in natural gas applications. We investigated seven alternatives in total, but after our initial analysis we eliminated 3 unfeasible alternatives which were: using biogas in fuel cells to produce heat and electricity, sending RNG to Peoples Gas (the local natural gas utility), and sending RNG to Eckerd college (which is adjacent to the southwest facility). Our four systems selected for final analysis are shown here. Biogas could fuel boilers to heat the digesters, or it could fuel internal combustion engines or microturbines, or RNG could be used to fuel the City ’s sanitation fleet vehicles. The City was interested in all four of these alternatives, especially fueling fleet vehicles.
George [1 minute or less] - This is our first alternative, using biogas as fuel for a boiler. This process mimics the system we assumed would already be in place, but the difference here is that 2 MMBtu/hr would be treated for hydrogen sulfide and then sent to a boiler capable of burning biogas and/or natural gas. We determined that a 60 HP boiler would be sufficient to heat the digester, but a second boiler would be recommended for redundancy. Water heated in the boiler would go through the system ’s heat exchanger that we conservatively estimated to be 80% efficient.
George [1 minute] Our second alternative, Fuel for Internal Combustion Engines could use 4.4 MMBtu/hr that would need to be treated for moisture, hydrogen sulfide and siloxanes to prevent excess maintenance and it would have to be slightly pressurized. We determined that a 500 kW system would be the largest the average biogas production could fuel. With an 85% runtime, ICEs could produce 425kW to the facility and provide the necessary heat to the digesters.
George [1 minute or less] Biogas as Fuel for Microturbines is our third alternative and would require 0.2 more MMBtu/hr than ICEs to produce 85 kW less power. Microturbines would require the same constituents to be removed as ICEs, though the gas would need to be treated to a higher quality and compressed to a higher pressure. Microturbines would also heat the digesters.
George [2 minutes or less] Finally, our fourth alternative was the one our client was most interested in. Fueling the fleet vehicles would require all of the biogas produced. It would have to go through moisture, hydrogen sulfide and siloxanes removal, as well as carbon dioxide removal through pressure swing absorption. At this point, 3 scenarios were investigated: 1 was to simply hook up to the local natural gas line provided by Peoples Gas. This would have be the best scenario because it would involve minimal construction and a small hook-up fee to transport the gas, but because of Peoples Gas lack of interest and concern of the RNG quality this scenario was eliminated. The Second scenario was constructing our own pipeline that would be 6 to 8 miles long and 6 to 8 inches in diameter, gas storage would also be required. But because the high construction and storage costs as well as the disruption of the St. Petersburg citizens, this scenario was eliminated. The third scenario is the one that is shown here. Where we would compress treated biogas to 4000 psi and fill tube trailers. A tube trailer can hold 1500 therms and at least 4 trailers would be required to meet the daily truck fueling needs. The trailers will be transported using the City ’s diesel semi truck to the sanitation department where the gas will be released into a distribution field. Pressure is lost during the release and a second compressor would be needed to bring the pressure back up to 3600 psi. And fleet vehicles will require 32,000 therms per month (compared to our estimated biogas production of 36,000 therms/month).
Nicole [1:20 min] {30s} These are the criteria we used to evaluate the alternatives and the weights were determined by the City and show the relative importance of each criteria. The first three criteria make up the economic considerations (weighted at 80%) and I will discuss these in the next sides. Flexibility was determined as an alternatives ability to accommodate to future changes. We considered changes in biogas production and energy prices. An alternative was preferred if it utilized a greater percentage of the biogas produced because flaring excess gas represents a lost opportunity for savings. With the new anaerobic digestion system, the plant operators will be learning a new system. Therefore, we preferred an alternative with low system complexity. Finally, an alternative was preferred for minimal air pollutant emissions.
Nicole_53 seconds (looks good without the bullets!) We reached to vendors, subject matter experts, and literature to estimate he construction and O&M costs of this project. These list the general items we considered and I will highlight a few. Percentages were used to estimate the installation and electrical and instrumentation costs, and we included fees expected for construction. For O&M, the City would need to purchase additional insurance to transport the RNG in tube trailers. Finally, savings was calculated as the price avoided by not purchasing electricity or natural gas. This would be due to an alternative ’s ability to reduce external energy consumption.
Nicole_45secs With these costs and savings, we calculated the 20-year Net Present Worth of each alternative compared to not utilizing the biogas. This means that a negative number represents a cost offset. The first row shows the construction costs from $370,000 to $14 million for fleet vehicles. The second row is the total net savings of each alternative from over the 20-year design period. This was calculated as the total savings minus the total O&M costs. Where internal combustion engines result in the most savings due to their great power and heat generation, and fleet vehicles would cost the City more to operate then they would provide savings. Therefore, Internal Combustion Engines are the most cost-effective alternative.
Matt [1 minute] It was important to us to highlight the prominent advantages and disadvantages of the alternatives. The best advantage of fuel for boilers is its low system complexity only requiring the removal of hydrogen sulfide from the biogas. A disadvantage is its low biogas utilization, consuming less than 50% of total production. Internal Combustion Engines have a great advantage with their superior flexibility. They can operate on different fuels, and provide the best benefit should electricity or natural gas prices go up or down. But its disadvantage is that it can have the worst air pollutant emissions of the four alternatives. Microturbines are modular and engine sizes are capable of utilizing smaller fractions of the biogas, although adding smaller engines can help maximize biogas use, microturbines provide lower power per cubic foot of biogas then say ICEs. And one of the only advantages of fleet vehicle fueling is that RNG emission factors are comparable to NG and emissions would still be better than diesel emissions. Fleet Vehicles have very high system complexity requiring a fairly complex rotation schedule, high quality biogas conditioning and upgrading systems, as well as multiple high pressure compressors.
Melissa Alternatives were scored relatively for each criteria from 1 to 10 (with 10 being the best). We then multiplied those scores by the criteria ’s associated weight and added scores to get the overall evaluation scores. Fleet vehicles received the lowest score of 1.9 out of 10 due to their extremely high cost and high complexity, despite having low emissions. Microturbines and boilers scored higher, but Internal Combustion Engines received the highest score due to their high 20-year cost offset, great annual savings, optimal flexibility and only moderate system complexity. Therefore, NGM3 recommended internal combustion engines to utilize biogas at the Southwest Water Reclamation Facility.
Matthew [1 minute] We chose to base our recommendation off of a 2G-Cenergy system composed of the 500kW Twin Pack. Their containerized modules house two 250kW engines made by MAN with a combined overall efficiency of 85%. The units include most necessary components for operation, such as ventilation, thermal and exhaust heat exchangers, flanged water hookup, imbedded equipment for constant offsite monitoring (should the City choose this option), the switchgear and necessary components for electrical hookup, as well as a compressor for the incoming gas. The modular design is built for indoor or outdoor use and is closely integrated with the 2G Biogas treatment equipment consisting of hydrogen sulfide and siloxanes removal by their appropriate carbon media filters, and moisture removal facilitated by a liquid gas chiller. To transport the digester gas, stainless steel 316L schedule 40 pipe will be required with the appropriate instrumentation.
Matthew [1 minute] The water to sludge heat exchanger will be part of the TPAD system (shown in grey), next to the digesters. 50 feet to the east, where an old clarifier currently sits, the City ’s consultant has recommended placing the thermophilic batch tank. There will still be room in this area for the internal combustion engines and biogas treatment pad, which sit 10’ by 60’ and 10’ by 10’. In fact, if the facility were to somehow greatly increase biogas production, there would still be room to install a second internal combustion engine.
Matthew [1 minute] An exaggerated display of the planned piping and instrumentation exemplifies the need for control and study within the system. For damage prevention, Condensate traps will be located at the system ’s low and isolation points. Gas flow meters, pressure gages and water separators are located at each isolation point throughout the system. Flame traps need to be installed where there is a risk of an open flame. Therefore they should be installed on the dual pressure/vacuum relief valves on top of the digesters and at the waste gas flares, but not at engines or boilers. The arrangement of shut off valves allows for continued operation and manipulation of the system while some equipment is out of operation. The need for a gas pusher will depend on what kind of digester covers will be selected, but would provide necessary pressure to the system.
Melissa [1 minute] We investigated permitting requirements necessary for this project, which is subject to all state and federal regulations for air emissions. We calculated air emissions for different scenarios and found the worst case scenario to determine which permit we would need. Under our recommended system, this facility will not be a major source emitter. Therefore, it will not be subject to Title V rules and regulations but will be required to complete a Non-Title V application for air permit through the FDEP. Finally, we also investigated new rules that will come into play later this year. Specifically code of federal regulations subpart quad Z. Even though the facility will not be a major source emitter, it will be an area source emitter of Hazardous Air Pollutants and will have to comply only with subpart Quad J.
We were privileged to engage with many people in the professional community, these three people in particular. Our patient group mentor, Juan Oquendo, from GSP, our meticulous professor, Dr. Sarina Ergas, and our visiting professor, Mr. Tom Cross from McKim and Creed. We are very thankful to all of them and we thank you for your time. This concludes our presentation and we ’d now like to take your questions.
Nicole [24 sec] This project gave us many opportunities to engage the professional community and we have many people to thank for their help and guidance. Three people were especially supportive: Our mentor Juan Oquendo from Gresham Smith & Partners, Dr. Sarina Ergas our professor, and our visiting professor Mr. Tom Cross from McKim and Creed. It was a privilege to work with all three of them. This will conclude our presentation and we can now take your questions. Times new roman and size of font.
Melissa (1 min) Brown and Caldwell recommended installation of a temperature phased anaerobic digestion system, sometimes called a TPAD system. Design specifications for new digesters and primary clarifiers are in progress. The future process will receive sludge from both primary and secondary clarifiers. Waste-activated-sludge from secondary clarification will be thickened by gravity belt before entering the first thermophilic digester. After digestion, all sludge will be dewatered by belt filter press and transported for land application. The two main types of anaerobic digestion—thermophilic and mesophilic—are distinguished by two different operating temperatures and different microbial species. TPAD systems are designed to capitalize on the positive attributes of both thermophilic and mespohilic digestion- faster digestion rates and enhanced waste stabilization, respectively. Due to the higher volatile solids destruction of such a system, biogas production is maximized. Biogas from municipal wastewater facilities is made up of approximately 60% methane, 35% carbon dioxide and 5% moisture and other undesired pollutants. For our calculations, we used a lower heating value of 560 Btu per cubic feet, compared to 1000 Btu per cubic feet for natural gas. Depending on end use of the biogas, biogas conditioning to remove certain constituents may be necessary. The City seeks to utilize the biogas that will be produced by the new system.
Mention used John Zink Combustion enclosed flare emission factors Criteria Pollutants: Ozone, Particulate matter, Lead. (but these were not significant and not available from all manufacturers ). Lead still in diesel fuel? “ Three of the major air criteria pollutants”
Melissa [1 minute] • This project is subject to applicable laws specified in Florida Statutes. These statutes allow the Florida Department of Environmental Protection to implement and enforce regulations regarding air quality as part of the Florida Administrative Code. This project is also subject to rules and regulations in the florida administrative code. Applicable federal regulations include Title 40 of the Code of Federal Regulations. • To determine permitting requirements, we calculated emissions for the 3 operational scenarios that could occur under the recommended system. • These scenarios are: operational ICE with excess biogas flared, backup boilers operating with excess biogas flared and 100% flare. The last two scenarios are only possible in the event of ICE and boiler system failures, respectively. • Emissions of GHG, CO2, methane, NOX, SOX, VOCs and particulate matter were calculated for each scenario determine the worst. We extrapolated these numbers to find emissions in tons per year. • Based on these calculations, NGM3 determined that this facility will not be considered a major source of pollutants and will therefore not be subject to Title V rules and regulations. • it will not require a Prevention of Significant Deterioration preconstruction review, and will not be subject to acid rain provisions of the Clean Air Act. • The SWWRF will be required to complete a Non Title V Source Application for Air Permit through the FDEP. • • The FDEP Air Resources Division oversees the acceptance, review, and issuance of air permits in the state of Florida. The facility will be considered a minor emitter and will be required to complete the “Application for Air Permit – Non Title V Source” document available through FDEP.
Nicole_20secs With this presentation, we complete phase 2 of the project, phase 3 has already begun because our final report for the competition is due in 5 days. Once the report is turned in, we will focus review all our work to prep for the final presentation and competition in April. And ultimately, phase 3 will result in a preliminary design for the recommended alternative that we will show the City in a month.
