biosolids drying systems - architects & engineers
TRANSCRIPT
Biosolids Drying SystemsCan they be part of an energy efficient project?
Agenda
Biosolids: The Problem
Biosolids Dryers
Case Studies
Proposed Approach
Biosolids: The Problem
What are Biosolids?
Biosolids Processing Optionso Thickeningo Dewatering o Drying
Treatment Technology: ThickeningGravity Thickening Flotation Thickening Mechanical Thickening
Advantages
• Lowest capital, energy, and O&M costs
• Simple to design, operate and maintain
• Good performance • Highest performance (4% to 6%)
• Require small to moderate size for working area
• Simple to design and operate
Disadvantages
• Lowerperformance
• Require larger footprint
• Aesthetic and odor concerns
• Highest capital, energy, and O&M costs
• Significant operator attention to operate and maintain
• Require larger footprint
• Medium capital, energy, and O&M costs
• Two waste streams (filtrate and belt washwater)
Treatment Technology: DewateringNatural Dewatering Mechanical Dewatering
Advantages
• Simple to design and operate• Requires less energy • Lower operational and chemical
costs
• High performance (20% - 35%)• Adaptable to varying influent solids
conditions• Moderate disposal and hauling costs• Requires small land area• Low capital costs
Disadvantages
• High capital costs• Effectiveness depends on climatic
conditions• Require periodic excavation and
removal of dewatered sludge -> expensive
• Require large land area
• Medium to high energy and chemical costs
• Requires moderate to significant operator attention
• Two waste streams (filtrate and belt washwater)
Treatment Technology: DryingOpen-Air Drying Mechanical Drying
Advantages
• Simple to design and operate• Requires minimal energy input• Lower O&M and chemical costs
• Achieve up to 97% solids• Low disposal and hauling costs• Requires low to moderate land area
Disadvantages
• Effectiveness depends on climaticconditions
• May require years to achieve the desired solids content
• Require large land area• Lower solids content output
• Higher energy, thermal, and chemical costs
• High capital costs• Two waste streams (filtrate and belt
washwater)
Biosolids Dryers
Graphic courtesy of Gryphon Environmental, LLC.
Operating Principle
Graphic courtesy of ELIQUO STULZ
Benefits
Disposal Methods• Burial in a Landfill • Beneficial Reuse
Regulatory Requirements/Guidelines
• Design residuals treatment processes:o 10 States Standardo AWWA Water Treatment Plant Design
• Disposal:o 1972 Clean Water Act (NPDES/USEPA) –
Regulation of Discharges to Natural Waterways, Regulation of Discharge into Sewer Systems
o Subtitle D of the Resource Conservation and Recovery Act (USEPA) – Regulation of Permanent Lagoons and Landfills
o 40 CFR 503 and 40 CFR 507 (ASCE/AWWA/EPA) – Regulation of Land Application
Type of Sludge Quality & Quantity
Disposal Types Available
Regulatory Restrictions
Sludge Quantity Reduction
Treatment Processes
Design Selection
Evaluation Approach
Desktop Analysis
Biosolids & Drying• Biosolids composition• Biosolids conveyance, storage and end
user loading• Alternate means of disposal during dryer
outages• Reduce costs and provide flexibility in
operation• Daily operations• Final equipment sizing and costs• Fuel source gas cleaning, blending,
compression, safety, and distribution.
Case Study:
Onondaga Water Environmental Protection (WEP)
Sludge Disposal Cost $3.4M Annually
Sludge Dryer Cost $14.5M (installed)
Dryer Fuel & Power Cost $500,000
Sludge Disposal Savings -$2.1M
Simple Payback 9.1 years
Diesel FuelEnergy Savings
23,700 Wet Tons Sludge Hauled Reduction
99 Miles of Hauling
234,000 Gallons Diesel Fuel
32,300 mmBTU in Energy Savings
Landscape Spreading Energy Savings
39,000 Wet Tons 15,000 Wet Tonnage
180 BTU/LB 16 BTU/LB due to Increased % Solids
14,000 mmBTU 500 mmBTU
13,500 mmBTU in Energy Savings
Case Study:
Village of Endicott Wastewater Treatment Plant
Project Driverso Address Failing
Infrastructureo Address Inefficient
Processo Do What Is “Right”
What makes a successful project?o Maintain Class A
Biosolidso Eliminate Existing
Compost Operation (Energy and Labor Costs)
o Enhanced Septage Receiving
What Are My Options?
o Do Nothingo Modify the
Existing Process (Can We Make it More Efficient?)
o Change the Process
Dryer Design Criteria o Utilize Excess Digester
Gas at Dryero “Future Max Month”
Solids Loading conditions within approximately 40 hours of operation per week
o Disposal to farmers with potential winter storage under existing canopy structure
Sludge Dryer Cost $3.0M (installed)Dryer Fuel & Power Cost -$14,250
Project Savings -$0.3M
Simple Payback 9.5 years
Proposed Approach for Sludge Drying
ICE: INTEGRATED CAPITAL & ENERGY IMPROVEMENTS
exploring the seen
and unseen.
ICE Approach Planning Phase Design Project
Improvements Implementation Results
ICE Benefits • Save Money, Reduce
Energy, Operational, & Maintenance Costs• Increase Revenue• Integrate Energy Efficiency
into Capital Improvement Programs• Additionally - Meet More
Stringent Regulations
Onondaga County WWTP• A comprehensive ICE evaluation
was performed on the six WWTPs making up the County System
• Over $24.5 million of integrated energy and capital improvements
• Over 6.3 million KWHrs of electrical savings and $2.1M of savings annually
• $2.3 million in energy incentives
• 11.6 year payback
Questions
Washington CountyEnergy Performance Contract
City of North Tonawanda Wastewater Treatment PlantBiosolids Dryer Analysis
Endicott Wastewater Treatment Plant UpgradesEngineering Design & Construction Services
Onondaga CountyEnergy Study & Energy Performance Contract
Town of AmherstBiosolids Dryer Analysis
Village of GowandaBiosolids Dryer Evaluation
Erie County Water AuthorityBiosolids Dryer Evaluation
Private Industrial ClientDryer Procurement & Design
Drinking Water Sludge
EPC for Biosolids Drying
Currently in Construction
Increased Revenues &
Biosolids Drying
THANK YOU