Composting Technologies and Costs Minggu 7

Overview b Technology in Composting Materials HandlingMaterials Handling Biological Process OptimizationBiological Process Optimization Odor ControlOdor Control b Capital Cost Increases with technologyIncreases with technology b Operational Costs Decrease with technologyDecrease with technology b Footprint (Area Required) Decreases with technology (usually)Decreases with technology (usually)

Technology Classification b Low - Tech WindrowWindrow b Mid - Tech Aerated Static PileAerated Static Pile Aerated Compost BinsAerated Compost Bins b High - Tech (In-Vessel) Rotary Drum CompostersRotary Drum Composters Box/Tunnel Composting SystemsBox/Tunnel Composting Systems Mechanical Compost BinsMechanical Compost Bins

Windrow Composting b Long, narrow piles agitated/turned regularly b Aeration by natural/passive air movement b Better suited to larger volumes b Composting Time: Months

Windrow Composting, cont. b Equipment Needed Grinder/Shredder Tractor/FEL Windrow Turner –tractor-pulled –self-propelled Screener b Manual labor costs excessive without equipment

Windrow Composting, cont. b Footprint One Acre Can Handle 4, ,000 CY Compost Mix b Costs Site Prep -Site Specific Asphalt/Concrete Pad ($12 - $27/square yard) Equipment –Grinder/Shredder : $3,500 –Tractor/Front End Loader : $50K - $150K –Windrow Turner : $30K - $200K –Screeners : $50K - $180K

Aerated Compost Bins

b Aeration Through Porous Floor Plates b Composting Time: Weeks b Curing Time: 2 Months b Durable Materials of Construction b Equipment Needed: Front End Loader b Vector/Vermin Control Needed With Food Wastes b Capacities: Days Food Waste + Bulking Agent Per Bin

Aerated Compost Bins At Caledonia b 12 Bins - Two Rows of 6 Bins b Construction Cost - $40,000 b Footprint - 50 SF per Bin b Capacity of Each Bin - 36 Barrels (35 - gal.) of Food Scraps b Blowers CFM b Aeration Plates - 2’ x 2’, $89 Each b Filling/Emptying - With Bobcat

Aerated Static Pile b Aeration Provided By Mechanical Blowers b Can Shorten Composting time to Weeks (followed by 30 days curing)

Aerated Static Pile b Better Suited to Larger Volumes (landscape debris and food waste) b May Not Be Suited to Wastes That Need Mixing During Composting, Like Food Wastes b Difficult to Adjust Moisture Content During Composting If Needed b Odor Control Difficult With Positive Aeration b Less Land Area Than Windrows, Still Labor Intensive

In-Vessel Systems Rotary Drum Composters

Rotary Drum Composters b Rotation Mixes, Aerates Compost Mix b Second - Stage Curing/Composting Needed b Food Waste Grinding and Mixing With Bulking Agent Needed Prior to Feeding Drum b Recipe For Drum Composting Food Wastes: 2 Parts Wood Chips2 Parts Wood Chips 1 Part Sawdust1 Part Sawdust 2 Parts Food Waste2 Parts Food Waste

Rotary Drum Composting at Brown Creek b Type 616 Greendrum Composter with Patz 9427 Chopper b Mounted on Tandem Axle Frame - moveable b Footprint SF b Daily Loading Rate - 2, ,000 Lbs/Day b Operating Capacity - 11 CY b Retention Time - 1 Week, Curing Time - 2 Months b Cost - Approx. $45,000

Box/Tunnel Composting Systems

Auburn Correctional Facility, NY b Wright Environmental Model 1500 (Model 750 shown)

Auburn Correctional Composting b Capacity: 1500 lbs/day b Composting Time: 4 Weeks b Curing Time: 1 Month b Labor - 2 Inmates b Cost: $123,000 b Disposal Savings: $33,000 / yr. (4-yr. Payback) b Footprint: 50’ Long x 10’ Wide

Mechanical Compost Bins b Green Mountain Technologies “Earth Tub” b Modular Design, Batch Operation b Capacity: 200 lbs/day b Composting Time: 4 Weeks; Curing: 1 Month b Footprint: 1 Parking Space b Cost: $6,000 b Labor: 1 Operator

Summary b Factors To Consider In Selecting Technology Available SpaceAvailable Space Available Labor (Inmate or Staff)Available Labor (Inmate or Staff) Vendor Previous Experience With Same FeedstocksVendor Previous Experience With Same Feedstocks Control of Odors, Vermin, and VectorsControl of Odors, Vermin, and Vectors Life - Cycle CostsLife - 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