UI C OMPOST S YSTEM D ESIGN AND P ILOT Green Machine

P ROJECT G OALS  The purpose of this project is to design, develop, and implement a composting system for the University of Idaho by July  This system will incorporate 100% of the food waste created by the university.  It will also process any animal carcasses produced by Vandals Meats, the university dairy, beef or sheep units.  The design will be flexible and allow for the possible expansion of operation in size and capability.  Secondarily, the design will allow for the possibility of producing a commercialized product, and for research into composting and waste streams.

N EEDS  Compost 100% of University of Idaho Food Waste  Compost all Dairy, Beef, and Sheep Carcasses  Robust and Expandable  Low Cost  Low Daily Manual Operations  Instructional Use Material (Operations Manual)

S PECIFICATIONS - W ASTE S TREAM  Food Waste: Approx. 100 tons/year sorted  Daily Waste Volume: <900 lbs/day  Carcasses:  6-7 Full Bovine Carcasses/year  60 gallon drum slaughter offal/month  Dairy manure with bedding for mixing  Final Product:  Dairy Bedding, C:N Ratio near 30:1

C OMPOSTING P ROCESS O VERVIEW 1. Separation and Sorting (occurs at facility) 2. Establish initial pile conditions for feedstock degradation, including pile structure, nutrient balance, oxygen %, and moisture % 3. Biodegradation and stabilization of the compost 4. Collection of air from process and treatment in biofilter (if required) 5. Finishing step to develop level of compost stability required and ensure sufficient degradation 6. Removes physical contaminants (glass, metal, plastics, etc.) and oversized materials (rocks, bulking agents) down to specified size

P ROCESS C ONTROL P ARAMETERS Nutrient Balance- C:N Control Pile Moisture % Control Pile Temperature Control Pile Oxygen % Overall Feedstock Ratio by weight (food waste: manure: wood chips) 1:.28 :.63 Total weight per day treated: 1700lbs weekdays

M IXER B ENEFITS AND C OSTS  Using a mixer prior to loading compost bays would provide smaller and more uniform particles, speeding the composting process and improving quality of product  Range for Mixer Costs $6221-$30000  140 cu. ft from Patz Corp. = $20000  Carbon Steel Paddle Mixer 46 cu. ft from Hayes & Stolz $25000-$30000  Used 36 cu. ft Carbon Steel Paddle Mixer from Aaron Equipment = $7000  S-1with 5.4 cu. ft mixer from H.C. Davis Sons Manufacturing = $6221

C URING  Provides additional stabilization  Further degradation  Can proceed until desired C:N ratio is achieved as further biological activity will lower the ratio as CO2 is released  Only requirement is space

G ENERAL C OMPOSTING T ECHNOLOGY C ONSIDERATIONS  Capital and operational costs are related to processing capacity of the technology and its sophistication  Capital costs increase with technology  Operational costs decrease with technology  Area requirements decrease with technology  Process control capability increases with technology  Processing capacity increases with technology

C OMPOSTING T ECHNOLOGIES Low-Tech Windrows Mid-Tech Aerated Static Pile Aerated Bins High-Tech In-Vessel Systems

Windrow Composting

W INDROW C OMPOSTING - M ECHANICALLY T URNED  Aeration by natural/passive air movement with periodic turning to build porosity, release trapped gases and heat  Suited for larger waste volumes  Large area required  Equipment reqs:  Tractor/FEL  Windrow Turner Tractor pulled Self propelled

W INDROW C OMPOSTING - M ECHANICALLY T URNED  Extensive labor required  No enclosure, ventilation  Typically 1 acre can handle cy of composting material  Seasonal weather will affect pile size and process speed  5-6 Weeks 1st phase

W INDROW C OMPOSTING - M ECHANICALLY T URNED  Advantages  Turning processes mix and pulverize compost for uniform end product  May require less final screening  Disadvantages  Space limited  Weather considerations  Low process control  Odor Release  Labor intensive

Windrow Composting Cost Breakdown  Equipment Cost:  Tractor/Front End Loader: $50,000-$150,000 (dairy owns)  Windrow Turner: $30, ,000 (FEL could be used instead)

Aerated Static Pile

W INDROW C OMPOSTING - A ERATED S TATIC P ILE  Mix of food waste, bulking agents, carcasses placed over perforated pipe on prepared base  Aeration positive or negative  Negative allows filtration for odor control  3-5 Weeks 1 st Phase

W INDROW C OMPOSTING - A ERATED S TATIC P ILE  Advantages  More space efficient  Fewer, larger piles  Reduced temperature variation  Closer process control  Shorter composting time  Less labor  Disadvantages  Higher capital cost  Collection of final product difficult due to piping  Control System for blower regulation  Pile drying  Areas of Anaerobic activity caused by pile settling  Learning curve, trial and error by operators

Aerated Static Pile Cost Breakdown  Flooring  Concrete: $5,000-$7,000  Blower  $3,000-$5,000  Piping  120 $10 per foot =$1,200  Mixer  $6,000-$20,000  Total Costs = $15,200-$33,200

A ERATED B INS

 Aeration in covered or uncovered bays through porous floor plates or perforated pipes  Size of bays can be changed  Large number of bays may be needed for continuous processing  Compost 3-4 weeks  Equipment  Front end loader  Blowers

A ERATED B INS  Advantages  Easy in-and-out rotational system  Compact  Rectangular piles in bins for simple loading, unloading  Disadvantages  Expensive construction  Anaerobic areas can develop

Aerated Bins Cost Breakdown  Flooring  Concrete: $5,000-$7,000  Elevated Flooring  $4,500  Blower  $3,000-$5,000  Piping  120 $10 per foot =$1,200  Mixer  $6,000-$20,000  Total Costs = $19,700-$37,700

I N -V ESSEL S YSTEMS

 Varied technology for volume of waste stream  Often modular systems, more containers or “boxes” can be added to expand systems  Careful process monitoring and control possible  Mixing occurs with fixed augers or agitated beds  Aeration forced  Systems insulated to retain heat  Employ leachate capture and management (moisture recycle)

I N -V ESSEL S YSTEMS  Advantages  Close process control  Low labor, highly automated  Disadvantages  Require extensive screening/shredding before process begins  Very expensive  Loading and Screening equipment cost  Still require curing  Not recommended for mortalities composting

In Vessel Options

B W O RGANICS  We make the following proposal for your food, manure, and wood shavings up to 4 cubic yards per day. To make an excellent bedding for dairy cows.  One Model 405 B W Organics composter, portable, w/1/3 hp drive unit $ 39,  One Model 910 U-trough screw loading conveyor $ 3,  One Model 101 mixer $ 8,  One Single phase electrical control panel $  Total equipment package fob Sulphur Springs, Texas $ 52,  Delivery and installation to Idaho $ 3,  Total $ 56,  Note: Customer to furnish single phase service to the control panel  Note: We would suggest some type roof structure cover approx. 20 ft by 40 ft to protect system and waste materials from rain, snow, and bitter north wind.  Note: Terms: 50% down with order, balance upon delivery

GREEN MOUNTAIN TECHNOLOGIES- EARTH TUB  Earth Tub System package for University capacity would cost about $38,000  Would consist of 3 separate units

BIOSYSTEM SOLUTIONS  $ K  Includes: Grinder (Mixer), Biochamber, Computers to automate  Pros: Possible partnership, Shared PR, Research center to reduce cost- $ K Not all up front  Cons: Doesn’t include site costs

C OMPETITIVE A NALYSIS

R ECOMMENDED S YSTEM Choice: Aerated Static Pile/Bin Initial Costs are the most manageable System will incorporate both food waste and animal carcasses Smaller foot print Expandable

 Site picture, labels how system sits on site

S YSTEM O PTIONS FlooringBlowerMixerControlScreener Steel DeckingOne Larger BatchManualBatch ConcreteMultiplePTOAutomaticNone AsphaltNone Gravel

C OMPETITIVE A NALYSIS : F LOORING Steel Decking Cost: Free, provided Concrete Cost: $5,000-7,000 Positives: Affordable Easy to install Can be installed without outside help Negatives: Possible Drainage Issues Life Span Flexible Positives: Long Life Span Ridged construction Pipe/Drainage Control Aesthetics Negatives: Cost Labor Intensive

C OMPETITIVE A NALYSIS : F LOORING Asphalt Cost: $2000 Gravel Cost: $ Positives: Long Life Span Pipe/Drainage Control Negatives: Cost Flexible Positives: Inexpensive Negatives: Shorter life span Sorting Problems Possible Drainage Problems

C OMPETITIVE A NALYSIS : B LOWER One Blower Cost: 3,000-5,000 Multiple Cost: 3,000-5,000 Positives: Fewer Moving Parts Simpler Filter Design Negatives: Cost If it breaks down, the whole operation stops Positives: Simpler Control Scheme Energy Saving Easy to Expand Negatives: Control Difficulty Increase Housing Cost Complication of Filter

C OMPETITIVE A NALYSIS : C ONTROL Manual Cost: None/Time Positives: Cost Less Power Requirements Negatives: Increased Labor Increased Composting Time Limited Control Automatic Cost: <$1,000 Positives: Less Management Faster Compost Time Negatives: Cost Increase Operator Knowledge

Recommended Components  Surface: Asphalt  Cost: $2000  Blower: Single  Cost: $5,000  Control System: Automatic  Cost: $1,000  Walls: Eco-Blocks  Cost: Free; $35 a block  Piping: Industrial Grade PVC  Cost: $10/foot  Mixer (Used)  Cost: $6,221  Total: $15,421

Future Schedule  Finalize Conceptual Design (Dec. 4)  Interim design report (Dec. 11)  Testing (January)  C/N ratio  Moisture Content  Density  Material Acquisition (February)  Build conceptual design (March)  Testing components of design (April)

R EFERENCES 1. Leege, Philip B. and Thompson, Wayne H Test Methods for the Examination of Composting and Compost. 1st Edition. Bethesda, MD. The US Composting Council. 2. Haug, Roger T The Practical Handbook of Compost Engineering. 2 nd Edition. Lewis Publishers. Boca Raton, FL. 3. Recycled Organics Unit Food Organics Processing Options for New South Wales. 2 nd Edition. University of New South Wales. Sydney, Australia.

R EFERENCES 4. Washington State University. October Compost Systems. Available at: ompSys.html#anchor Accessed 20 October Renewable Carbon Management, LLC. Available at: Accessed 20 October Green mountain Technologies. In-Vessel Systems. Available at: Accessed 20 October 2009.