Transcript UI Compost System Design and Pilot

UI COMPOST SYSTEM DESIGN AND PILOT
Green Machine
PROJECT GOALS
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The purpose of this project is to design, develop, and
implement a composting system for the University of
Idaho by July 2010.
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.
NEEDS
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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)
SPECIFICATIONS- WASTE STREAM
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Food Waste: Approx. 100 tons/year sorted
 Daily
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Waste Volume: <900 lbs/day
Carcasses:
 6-7
Full Bovine Carcasses/year
 60 gallon drum slaughter offal/month
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Dairy manure with bedding for mixing
Final Product:
 Dairy
Bedding, C:N Ratio near 30:1
COMPOSTING PROCESS OVERVIEW
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
PROCESS CONTROL PARAMETERS
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
MIXER BENEFITS AND COSTS
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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
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CURING
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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
GENERAL COMPOSTING TECHNOLOGY CONSIDERATIONS
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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
COMPOSTING TECHNOLOGIES
Low-Tech
• Windrows
Mid-Tech
• Aerated Static Pile
• Aerated Bins
High-Tech
• In-Vessel Systems
Windrow Composting
WINDROW COMPOSTINGMECHANICALLY TURNED
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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
 Tractor
Turner
pulled
 Self propelled
WINDROW COMPOSTINGMECHANICALLY TURNED
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Extensive labor required
No enclosure, ventilation
Typically 1 acre can handle 5000-7000 cy of
composting material
Seasonal weather will affect pile size and process speed
5-6 Weeks 1st phase
WINDROW COMPOSTINGMECHANICALLY TURNED
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Advantages
 Turning
processes mix and pulverize compost for
uniform end product
 May require less final screening
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Disadvantages
 Space
limited
 Weather considerations
 Low process control
 Odor Release
 Labor intensive
Windrow Composting Cost Breakdown
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Equipment Cost:
 Tractor/Front
End Loader: $50,000-$150,000 (dairy
owns)
 Windrow Turner: $30,000-200,000 (FEL could be used
instead)
Aerated Static Pile
WINDROW COMPOSTINGAERATED STATIC PILE
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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 1st Phase
WINDROW COMPOSTINGAERATED STATIC PILE
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Advantages
 More
space efficient
 Fewer, larger piles
 Reduced
temperature
variation
 Closer process
control
 Shorter composting
time
 Less labor
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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
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Flooring
 Concrete: $5,000-$7,000
Blower
 $3,000-$5,000
Piping
 120 feet @ $10 per foot =$1,200
Mixer
 $6,000-$20,000
Total Costs = $15,200-$33,200
AERATED BINS
AERATED BINS
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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
AERATED BINS
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Advantages
 Easy
in-and-out rotational system
 Compact
 Rectangular piles in bins for simple loading, unloading
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Disadvantages
 Expensive
construction
 Anaerobic areas can develop
Aerated Bins Cost Breakdown
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Flooring
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Elevated Flooring
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120 feet @ $10 per foot =$1,200
Mixer
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$3,000-$5,000
Piping
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$4,500
Blower
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Concrete: $5,000-$7,000
$6,000-$20,000
Total Costs = $19,700-$37,700
IN-VESSEL SYSTEMS
IN-VESSEL SYSTEMS
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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)
IN-VESSEL SYSTEMS
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Advantages
 Close
process control
 Low labor, highly automated
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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 ORGANICS
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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.
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One
Model 405 B W Organics composter, portable, w/1/3 hp drive unit
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One
Model 910 U-trough screw loading conveyor
$ 3,450.00
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One
Model 101 mixer
$ 8,950.00
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One
Single phase electrical control panel
$
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Total equipment package fob Sulphur Springs, Texas
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Delivery and installation to Idaho
Total
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Note:
$ 39,400.00
650.00
$ 52,550.00
$ 3,500.00
$ 56,050.00
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
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Earth Tub System package for University capacity
would cost about $38,000
Would consist of 3 separate units
BIOSYSTEM SOLUTIONS
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$300-350K
 Includes:
Grinder (Mixer), Biochamber, Computers to
automate
 Pros: Possible partnership, Shared PR, Research center
to reduce cost- $150-175K
 Not
 Cons:
all up front
Doesn’t include site costs
COMPETITIVE ANALYSIS
Alternatives
Attributes
Initial Cost
Space Requirement
Smell
Maintenance Costs
Weekly Management
Animal Carcasses
Length of Composting
Time (typical) (Days)
Curing Time
Environmental Control
Aerated
Wind Rows
Static Pile
$
30,000 $ 15,441
High
Medium
High
Low
Low
Medium
High
Medium
No
Yes
60
1-2 Months
Low
In Vessel
Aerated Bed
$
56,050 $
19,700
Low
Medium
Low
Low
High
Medium
Low
Medium
No
No
28
1-2 Months 2 Months
Medium
High
21
21
2 Months
Medium
COMPETITIVE ANALYSIS
Weighted Alternatives
Additive Weighting Chart Wind Rows
Initial Cost
0.64
Space Requirement
0.00
Smell
0.00
Maintenance Costs
1.00
Weekly Management
0.00
Animal Carcasses
0.00
Length of Composting Time
(typical) (Days)
Curing Time (Days)
Environmental Control
Sum
0.00
1.00
1.00
Weighted Aerated Static
Value
Pile
Weighted Value
0.14
1.00
0.22
0.00
0.50
0.10
0.00
1.00
0.00
0.14
0.50
0.07
0.00
0.50
0.01
0.00
1.00
0.11
0.00
0.08
0.06
0.42
0.82
1.00
0.50
0.14
0.08
0.03
0.76
In Vessel
0.00
1.00
1.00
0.00
1.00
0.00
1.00
0.00
0.00
Weighted
Weighted
Value
Aerated Bed
Value
0.00
0.90
0.20
0.19
0.50
0.10
0.00
1.00
0.00
0.00
0.50
0.07
0.03
0.50
0.01
0.11
0.00
0.00
0.17
0.00
0.00
0.39
1.00
0.00
0.50
0.17
0.00
0.03
0.57
RECOMMENDED SYSTEM
•Choice: Aerated Static Pile/Bin
•Initial Costs are the most manageable
•System will incorporate both food waste
and animal carcasses
•Smaller foot print
•Expandable
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Site picture, labels how system sits on site
SYSTEM OPTIONS
Flooring
Blower
Steel Decking
One Larger
Concrete
Asphalt
Gravel
Mixer
Control
Screener
Batch
Manual
Batch
Multiple
PTO
Automatic
None
None
None
COMPETITIVE ANALYSIS: FLOORING
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
COMPETITIVE ANALYSIS: FLOORING
Asphalt
Cost: $2000
•Positives:
•Long Life Span
•Pipe/Drainage Control
•Negatives:
•Cost
•Flexible
Gravel
Cost: $500-750
•Positives:
•Inexpensive
•Negatives:
•Shorter life span
•Sorting Problems
•Possible Drainage Problems
COMPETITIVE ANALYSIS: BLOWER
One Blower
Cost: 3,000-5,000
•Positives:
•Fewer Moving Parts
•Simpler Filter Design
•Negatives:
•Cost
•If it breaks down,
the whole operation stops
Multiple
Cost: 3,000-5,000
•Positives:
•Simpler Control Scheme
•Energy Saving
•Easy to Expand
•Negatives:
•Control Difficulty
•Increase Housing Cost
•Complication of Filter
COMPETITIVE ANALYSIS: CONTROL
Manual
Cost: None/Time
Automatic
Cost: <$1,000
•Positives:
•Cost
•Less Power Requirements
•Negatives:
•Increased Labor
•Increased Composting Time
•Limited Control
•Positives:
•Less Management
•Faster Compost Time
•Negatives:
•Cost
•Increase Operator Knowledge
Recommended Components
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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
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Finalize Conceptual Design (Dec. 4)
Interim design report (Dec. 11)
Testing (January)
 C/N
ratio
 Moisture Content
 Density
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Material Acquisition (February)
Build conceptual design (March)
Testing components of design (April)
REFERENCES
1.
2.
3.
Leege, Philip B. and Thompson, Wayne H.1997.
Test Methods for the Examination of Composting and
Compost. 1st Edition. Bethesda, MD. The US
Composting Council.
Haug, Roger T. 1993. The Practical Handbook of
Compost Engineering. 2nd Edition. Lewis Publishers.
Boca Raton, FL.
Recycled Organics Unit. 2007. Food Organics
Processing Options for New South Wales. 2nd
Edition. University of New South Wales. Sydney,
Australia.
REFERENCES
4.
5.
6.
Washington State University. October 2000.
Compost Systems. Available at:
http://organic.tfrec.wsu.edu/compost/ImagesWeb/C
ompSys.html#anchor21101. Accessed 20 October
2009.
Renewable Carbon Management, LLC. Available at:
http://composter.com/. Accessed 20 October 2009.
Green mountain Technologies. In-Vessel Systems.
Available at:
http://www.compostingtechnology.com/. Accessed
20 October 2009.