Harvest Power in Central Florida A Sustainable Approach to Organics Co-Digestion: Harvest Power’s Biogas Plant at Reedy Creek Improvement District WWTP
Presented by:Dale L Doerr. MBAFacility Manager for Harvest Power Orlando
Recycle Florida Today 2014 Annual Conference June 8 - 10, 2014
About Harvest
• Industry leader, managing >2 million tons of organic materials as the largest processor of yard waste & food waste in North America
• Operates 40 processing facilitiesin North America with more than 600 employees, >$160 million inannual revenue
• Operating 3 of North America’s largest commercial anaerobic digestion facilities.
Founded in 2008, Harvest is creating a more sustainable futureby helping communities meet the challenges at the intersectionof waste, agriculture and energy in the 21st Century
Reedy Creek Improvement District (RCID)
• Established in 1967, RCID is a special taxing district and the regulating authority for the Walt Disneyworld Resort and the cities of Lake Buena Vista and Bay Lake.
• RCID is a very sophisticated gov’t entity. Manages roads, horticulture, water, wastewater, waste management, building permissions, and power distribution within its territory
• RCID has long been an innovator in organic waste management, and composted everything (food waste, biosolids, green waste, animal waste)
• Project Drivers: Looking to eliminate odors and ongoing organic waste management responsibility
3Proprietary & Confidential
Start-Up: Fall 2013
Capacity: 130,000 tons/year Organics Recycling
Energy Output: 5.4 MW CHP
Product Output: 5,000 tons/year granular fertilizer, 300 tons/year struvite fertilizer
Location: Adjacent to RCID WWTP
Harvest Power Orlando
Major Facility Components
•TWAS receiving from RCID WWTP
•Organic Waste Receiving and Processing
•FOG Waste Receiving
•Anaerobic Digestion System
•Liquid Side Stream Treatment
•Digestate Management
•Odor Control
•Biogas Conditioning and CHP5Proprietary & Confidential
Exhaust From Dryer
Foul Air from Receiving Hall
Clean Air5
b.
c.
d.a.
1FEEDSTOCK RECEIVING & DECONTAMINATION
a. Food waste contaminant removal b. FOG receiving c. TWAS pumped from WWTP d. Mix tank
Simplified Process Flow Diagram2
a.
b.
c.
a.
Food Waste
FOGs
1a.
b.
d.
Exhaust
Electricity
3
d.
a.
e.
b.
c.
2 ANAEROBIC DIGESTERS a. Anaerobic Continuous Stir-Tank Reactor (CSTR) Digesters b. Post-digester c. Integrated gasholder
3BIOGAS CONDITIONING & CHP
a. Biogas scrubber, water and particulate knockout b. Emergency flare c. Engine gen-set d. Water jacket heat recovery for process heat e. Thermal oil exhaust heat recovery for dryer
4 DIGESTATE MANAGEMENTa. Digestate fine screen b. Centrifuge for liquid/solids separation c. Digested solids indirect dryer d. Struvite phosphorus recovery from centrate e. Liquid effluent Annamox de-nitrification
5 ODOR CONTROLa. Food waste receiving hall b. Collection ducts and blower c. Odor removal bio-scrubber d. Stack w/ odor monitoring
Wastewater sludge
c.
Fertilizer
Struvite
Effluent to WWTPMg+4
e.
b. c.
d.
Polymer
a. Digestate Screenings
Contaminants
7
Process Highlight – Food Waste Receiving
• Food Waste Receiving• SS-lined concrete receiving
pit w/clamshell Bucket
• Feed hopper
• Turbo-separator
• Rejects conveyor & bin
• 150 Ton/Day
8
Process Highlight – Feedstock Receiving• Fats Oils & Greases (FOG)
• Decanted/un-decanted grease trap wastes
• Manually cleaned perforated plate screen
• Pump mixing & heating prior to transfer
• Tank capacity 20,000 Gallons
Process Highlight – TWAS Receiving
• Thickened Waste Activated Sludge (TWAS) pumped directly from the WWTP
• Base Feed Stock− 50,000 Gallons per day
− 5% - 6% solids
• Mix Tank − Homogeneous
9Proprietary & Confidential
10
Process Highlight – Anaerobic Digestion
• Two Primary Digesters (CSTRs)• 1,200,000 gallons each
• Top mounted mixers
• Side mounted scum breakers
• Mesophillic (85° F - 105° F)
11
Process Highlight – Anaerobic Digestion
• Post Digester• 960,000 gallons
• Side mounted mixers
• Dual Membrane Gas-holder Cover
• Un-Heated
• 500,000 ft3 Gas Storage
• Centrate treated to meet effluent limits set by RCID
• 85% Phosphorus reduction recovery occurs in a fluidized bed of sand
• Struvite pellets discharged to dewatering hopper
12
Process Highlight –Side stream Treatment
• Nitrogen reduction using World Water Works Demon® process
− Anammox bacteria perform anaerobic ammonia oxidation effluent by combining nitrite with ammonia
− SBR system provides 85% Ammonia Nitrogen reduction
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Process Highlight – Side stream Treatment
14
Process Highlight - Digestate Management
• Algiar® Vibrating Screen
• Digestate screening system prior to dewatering
• Removes fibrous material prior to dewatering and
drying.
15
Process Highlight - Digestate Management
• Flottweg® Dewatering centrifuge, thickens digestate from 5% solids to 25% Solids
16
Process Highlight - Digestate Management
• Komline Sanderson® Indirect heat paddle dryer• Thermal Oil is Heated
by the exhaust heat recovered from CHP
• Dries thickened digestate from 25% solids to >92% solids and produces granular Class AA fertilizer
17
Process Highlight - Digestate Management
• Fertilizer load-out bin, 80,000 ft3 Storage
• Granular fertilizer registered with FL under the product name “Florganics” (NPK 6-6-0)
• Biofilter System − Odors from multiple sources
to biological filter
− Activated carbon polishing
− >99% H2S and >90% odor removal
− Treated air vented out stack (60’ high)
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Process Highlight – Odor Control System
• Odor Monitoring− OdoWatch® - Odor Smart
Monitoring system
− 24/7 odor measurement with eNoses
− Software models the atmospheric dispersion and displays the site’s odor plume
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Process Highlight – Odor Control System
20
Process Highlight – Biogas Conditioning
• Biogas Conditioning
• Wet scrubber for hydrogen sulfide removal
• Chiller Unit for moisture removal
21
Process Highlight – CHP
• CHP• 2 - 1.6 MW CAT
Generators
• 2.2 MW thermal energy
22
HPO Facility Benefits Summary
• 3.2 MW renewable electricity • 30,000 tons/year of NEW organic waste diversion• 55,000 tons CO2e offset
• Solved organics management & odor issues for RCID• All RCID organic wastes (except green yard waste)
processed for beneficial re-use
• Over 5,000 tons of granular fertilizer per year• 300 tons of phosphorus-rich struvite per year
