Composting Technologies and Costs
Minggu 7
Overview
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Technology in Composting
• Materials Handling
• Biological Process Optimization
• Odor Control
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Capital Cost
• Increases with technology
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Operational Costs
• Decrease with technology
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Footprint (Area Required)
• Decreases with technology (usually)
Technology Classification
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Low - Tech
• Windrow
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Mid - Tech
• Aerated Static Pile
• Aerated Compost Bins
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High - Tech (In-Vessel)
• Rotary Drum Composters
• Box/Tunnel Composting Systems
• Mechanical Compost Bins
Windrow Composting
Long, narrow piles agitated/turned regularly
 Aeration by natural/passive air movement
 Better suited to larger volumes
 Composting Time: 3 - 6 Months
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Windrow Composting, cont.
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Equipment Needed
• Grinder/Shredder
• Tractor/FEL
• Windrow Turner
– tractor-pulled
– self-propelled
• Screener
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Manual labor costs
excessive without
equipment
Windrow Composting, cont.
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Footprint
• One Acre Can Handle 4,000 - 7,000 CY Compost Mix
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Costs
• Site Prep -Site Specific
• Asphalt/Concrete Pad ($12 - $27/square yard)
• Equipment
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Grinder/Shredder : $3,500
Tractor/Front End Loader : $50K - $150K
Windrow Turner : $30K - $200K
Screeners : $50K - $180K
Aerated Compost Bins
Aerated Compost Bins
Aeration Through Porous Floor Plates
 Composting Time: 2 - 3 Weeks
 Curing Time: 2 Months
 Durable Materials of Construction
 Equipment Needed: Front End Loader
 Vector/Vermin Control Needed With Food Wastes
 Capacities: 3 - 4 Days Food Waste + Bulking Agent
Per Bin

Aerated Compost Bins At Caledonia
12 Bins - Two Rows of 6 Bins
 Construction Cost - $40,000
 Footprint - 50 SF per Bin
 Capacity of Each Bin - 36 Barrels (35 - gal.) of Food
Scraps
 Blowers - 980 CFM
 Aeration Plates - 2’ x 2’, $89 Each
 Filling/Emptying - With Bobcat
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Aerated Static Pile

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Aeration Provided By Mechanical Blowers
Can Shorten Composting time to 3 - 5 Weeks (followed by
30 days curing)
Aerated Static Pile
Better Suited to Larger Volumes (landscape
debris and food waste)
 May Not Be Suited to Wastes That Need Mixing
During Composting, Like Food Wastes
 Difficult to Adjust Moisture Content During
Composting If Needed
 Odor Control Difficult With Positive Aeration
 Less Land Area Than Windrows, Still Labor
Intensive
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In-Vessel Systems
Rotary Drum Composters
Rotary Drum Composters
Rotation Mixes, Aerates Compost Mix
 Second - Stage Curing/Composting Needed
 Food Waste Grinding and Mixing With Bulking
Agent Needed Prior to Feeding Drum
 Recipe For Drum Composting Food Wastes:

• 2 Parts Wood Chips
• 1 Part Sawdust
• 2 Parts Food Waste
Rotary Drum Composting
at Brown Creek
Type 616 Greendrum Composter with Patz 9427
Chopper
 Mounted on Tandem Axle Frame - moveable
 Footprint - 200-300 SF
 Daily Loading Rate - 2,000 - 5,000 Lbs/Day
 Operating Capacity - 11 CY
 Retention Time - 1 Week, Curing Time - 2 Months
 Cost - Approx. $45,000

Box/Tunnel Composting Systems
Box/Tunnel Composting Systems
Auburn Correctional Facility, NY

Wright Environmental Model 1500 (Model 750 shown)
Auburn Correctional Composting
Capacity: 1500 lbs/day
 Composting Time: 4 Weeks
 Curing Time: 1 Month
 Labor - 2 Inmates
 Cost: $123,000
 Disposal Savings: $33,000 / yr. (4-yr. Payback)
 Footprint: 50’ Long x 10’ Wide
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Mechanical Compost Bins
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Green Mountain
Technologies “Earth Tub”
Modular Design, Batch
Operation
Capacity: 200 lbs/day
Composting Time: 4
Weeks; Curing: 1 Month
Footprint: 1 Parking Space
Cost: $6,000
Labor: 1 Operator
Summary
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Factors To Consider In Selecting Technology
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Available Space
Available Labor (Inmate or Staff)
Vendor Previous Experience With Same Feedstocks
Control of Odors, Vermin, and Vectors
Life - Cycle Costs
– Capital Costs And All O&M Costs Over Expected Life Of System
– Low - Tech: Lower Capital; Higher Operating Costs
– High - Tech: Higher Capital; Lower Operating Costs