jjc senior final.pptx

Senior DesignUtilization of Food Waste Joe Hummer, Cassidy Laird, James Rogers23 November, 2015

IntroductionRecognize and Define

Problem• Americans waste ⅓ food

•133 billion pounds/yr (513 Tg)•National food waste limit (50% by

2030)1 • Clemson University

•Same situation•30,000 people•700 tons/year (635,000 kg/year)•Composting in place

1. Aubrey, 2015. Image from Briggs, 2013.

Define Goals• Biological

•Design process to consume significant amount of food waste (130 kg/day)

•Viable products to offset time/costs•Reduce food waste to usable compost (GI

> 80%)1

• Structural•Batch, continuous, or plug flow design•Able to contain decaying food waste

• Mechanical•Heater and/or fan to provide constant

temperature•Oxygen/Moisture control (varies)•Able to remove products for utilization

1. Zucconi et al, 1981

Constraints/Considerations• Constraints

•Required size can fit within campus infrastructure (Cherry Crossing: ~3 Acres )

•Must be compatible with existing transport and loading equipment

•Staff time is limited• Considerations

•Nutrient rich compost runoff can be a pollutant•Harmful and pathogenic bacteria present in

decaying material•Large amounts of fresh food can attract local

wildlife•Anaerobic reactions can produce potent

greenhouse gasses

User, Client & Designer Questions• User

•What type of training will I need to operate this system?

•What type of maintenance will the system require?

•How frequently will the system parameters need to be checked?

• Client•What is the expected return on investment?•How consistent do the system conditions need

to be?•How consistent are the properties of the

products?• Designer

•What state will the food waste come in as?•How much waste will come in per day?•What, if any, systems already exist to address

the problem?

Literature Review

Past Data

Compiled from the municipal waste documents of Tom Jones, Director of Custodial & Recycling Services, Clemson University Facilities

Past Data• Compost Analysis Report

Compound Wet basis [%] Dry Basis [%]

Total Nitrogen 1.01 4.10

Carbon 12.37 50.04

C:N Ratio 12.21 12.21

Crude Protein 6.3 25.6

Fiber - NDF 5.9 23.7

Nonfiber Carbs -- 33.1

Fat 3.5 14.3

Ash 0.8 3.2

Bulk density

399 lb/yd3

Moisture 75.28 %

Performed October 2014 by the Clemson University Agricultural Service Laboratory

Possible MethodsStatic Pile

Composting

• Relatively easy to maintain

• Fertilizer • Length of process

•1-6 mos., + curing 1

• Low mass reduction (20%)2

Anaerobic Digestion

• Production of biogas• Faster than static

composting (30+ days)3

• 40% mass reduction4

• More complex installation

• Higher costs - labor, implementation

•Up to $11,000-51,000 per year5

And...

1. Zucconi et al, 19812. Cornell Composting3. American Biogas

Council4. Appels, et al., 2011. 5. Michigan Farm Bureau

Black Soldier Flies

• Self-harvest• Valuable products • Waste reduction

(40-60%)1 1. Diener, et al., 2009.

Potential Models• Fed Batch

•BioPods• Continuous

•Vermicomposting (flow through)

Food waste in

Fertilizer

Food waste in

Fertilizer out

Habitable zone

Fertilizer

Habitable zone

Larvae

Food Waste Composition Over Time

1. Ritika, 2015.

Black Soldier Flies• Current system (BioPods)

•4 pods that hold 38.5 kg (85 lbs) of food each1

•consumes 11.3 kg (25 lbs) of food per pod per day

•produces 0.454 kg (1 lb) of BSF per day (on average)

•Cleaned every 70 days (depending on larvae density)

1. Approximate values from David Thornton, organics and Biofuels Project Director

Image from Binh Dinh, 2012.

Black Soldier Flies• Temperature ranges

•Survive- 0-45 ℃1

•Thrive- 23-43 ℃2 • Moisture Content

•Ideal- 50-60%3

• Available Oxygen •Habitable- 15-20%4

• Microorganism reduction•At 31℃, 99.99% reduction of E. coli5

• Composition varies with diet1. Newby, 19972. Newby, 19973. Houg, 19934. Houg, 19935. Liu, et al., 2008

• dm/dt equals zero in steady state (SS) conditions• Multiple reactions can occur in a given system• Sometimes easiest to analyze a process with multiple

mass balances

Mass Balance Equations

Steady State Non-Steady State

Ficks Law

• Where:•Fx is mass flux through the system•D is diffusivity, a constant of the

medium•C is concentration of mass•x is distance into system

Governing Equations• Growth Rate

•Sigmoidal model used in insect growth literature

• Most interested in knowing development time

k = growth constanta = k*inflection timeb = k1. Banks, et al., 2014.

Governing Equations• Thermodynamics and Heat Transfer

•Thermal Energy Equation

•Heat generation term - modified Arrhenius

1. Gillooly, et al., 2001.

1

Governing Equations• Aerobic Respiration

• Chemical Oxygen Demand•For complete oxidation

• Moisture Mass Balance

1. Houg, 1997

1

1

1

Heuristics• Past experience with BSF

•Joe and James• Internships - composting• Past data from waste stream composition

analysis• Experience in classes and labs

•Microorganisms and growth rates •Bioreactors and design•Mass and energy balances

Collected Field Data• Density

Volume of food waste added: 2 gal = 0.00757082 m3

Mass of food waste added 7.803 kg

Density (m/V) = 7.803 kg/0.00757082 m3

= 1030 kg/m3

Optimum Moisture Analysis• Confirmed optimum moisture of media as a

fraction of field capacity

Wightman et al

Confirming Development Time and Weights

• Pupation time has potential to be as small as 10 days

Design Methodology & Materials

Analysis of Information

• Based on the information gathered through journal articles, company websites, and heuristics, the Black Soldier Fly design is believed to be the best option.

• BSFs reduce food waste at a much faster rate and produce multiple valuable products

• Compatible with current research at Clemson

Analysis of Information

• Identify knowns/given inputs: •Mass flow rate (130 kg per day)•Constant daily influent•Needs to fit at Cherry Crossing

• Determine important design factors with black soldier flies based on sources

•Temperature - winterization (year round operation)

•Air flow/oxygen - fans/pumps•Moisture content•Ramp slope/roughness•Feeding rate

• Mass Balances with respect to:•Food: •Fertilizer:

• Biomass:

• Total BSF Mass Balance:

Mass Balance Analysis

0

00

0

Growth Analysis• Rgrowth = Final weight/development time = average weight

gain/time❖ Development time➢ affected nonlinearly for

feeding rate, temp, and moisture

❖ Final weight➢ affected linearly by

feeding rate

1. Data from Diener, et al., 2009.

Synthesis of Design

Fed Batch (BioPods) Continuous (Vermicomposting)

Image from Olivier, 2004.

Image from Vermivision, 2012.

Design Options

Sizing for Food Waste• Based on TOC analysis, 40 days are needed

for complete food removal• assuming:

•A habitable depth of 6” (0.152 m):•Food waste density of 1029 kg/m3 1

• Retention area:Aretention= (Ṁfood*τfood/ρfood)/(dhabitable)Aretention= (130 kg/day*40 days/1029 kg/m3)/(.152 m)=33.1 m2

• Daily thickness:130 kg/day*40 days ÷ 28.4 m2 = 0.44 cm

1. epa.vic.gov.au

Batch Process Reactions

Time (days)

Optimizing Population• For a given population:

•τBSF = development time = 7.57*Rfeeding

-0.379

•Rfeeding = Ṁfood/Population = Ṁfood/(Eggsin*τBSF)

• Can control feeding rate by adjusting daily egg and food input

• Change inputs to yield the most products

Dev

elop

emen

t tim

e (d

ays)

Gro

wth

rate

(g/d

ay)

Com

post

er B

iom

ass

(g)

Time (days)

Aeration of Media• Approached as a method of increasing

habitable depth and decreasing surface area needed

• Flow of oxygen in reaches equilibrium with oxygen uptake rate

• Needed to determine oxygen uptake rate

Carbon-Oxygen Demand

• O2 consumption directly related to growth/activity with microbes

• COD = 1.44 g O2/g FW• At STP:

•[O2]air = 23.2% (by wgt)•ρair = 1.20 kg/m3

•Volume of air required for total oxidation of daily food waste in flow is 168,350 L air/day

Aeration of Media• Assuming:

•Rrespiration = 0.5683 μl/mg/hr1

Fx = -D*(dc/dx) = Biomass*Rrespiration/AcomposterFx = 1000 mgBSF*0.5683 /0.621 m2= 915.1 μl/hr/m2

1. Nespolo, et al., 2003.

Flow of Oxygen

Moisture• Composting tends to be a dehydrating

environment•biological activity decreases at

moisture levels < 50%

• Assume:•Ss = 25%, Sp = 40%

• W = (1-0.25)/0.25 - (1-0.40)/0.40 = 1.50 g H2O/g dry FW

• Must lose 48.75 kg of water per day to maintain 60% moisture content in reactor

•or 1.50 g H2O for every gram of dry FW added

Side effects of Aeration • dm/dt = Wrespiration-Wevaporation≠ 0• Evaporation increases with

aeration•Water source needed with

aeration

Synthesis of DesignWinterization

• Determination of heat generation constants

`

1. Gillooly, et al., 2001.

Temperature-1 (1000/K)

ln (B

0/m3/

4 ) (W

/g3/

4 )

BO ≍ Eg in energy balance

Synthesis of Design• Flow of Thermal Energy

Synthesis of DesignAmbient Temp. (K) Method Final Temp. (K) Final Temp. ( )℃

318

(45 )℃

m= 0.9 kg/s 299 26

m= 0.9 kg/sWood insul., 1 in thick

299 26

m= 0.005 kg/sWood insul., 1 in thick

320 47

298

(25 )℃

m= 0.9 kg/s 298 25

m= 0.9 kg/sWood insul., 1 in thick

298 25

m= 0.005 kg/sWood insul., 1 in thick

300 27

273

(0 )℃

m= 0.9 kg/s 281 8

m= 0.9 kg/sWood insul., 1 in thick

293 20

m= 0.005 kg/sWood insul., 1 in thick

275 2

m= 0.9 kg/s, Full wood insul., 1 in 296 23

Extending Living Space

• Same amount of oxygen is needed, but aeration must supply minimum concentrations (15%) throughout

• Available oxygen must be greater than or equal to respiration rate or dead zone appears

Aeration Placement: Too Deep

Aeration Placement: Too Shallow

Goldilocks!• Placed 0.26 meters (10.2”) deep• Habitable zone greater than 0.4 meters

(15.7”)

Aeration Through Piping• Based on minimal oxygen concentrations

at 5.1”•dead zones are possible at 5.1” from

any air source•must space aeration to eliminate

dead zones

Far zone

5.1”5.1”

5.1”

x x

45°45°

x = sin(45°)*5.1” = 3.62”

Spacing = 2*x = 7.24”

Pipe Sizing• Using orifice equations:

•⅛” (3.2 mm) orifice diameter•8 radial orifices per segment•7.24” spacing•2” pipe diameter•alternating air flow between pipes

(below)•7 psi stagnation pressure

air

air

Crowe et al 2009

Physical Design• Side view

❖ Top View

How Constraints Handled

• Limited staff time•40 minutes per day for feeding•1 hour per day for BSF nursery

• Ramps on vermicomposter•Dividers w/ramps

• Winterization - heated air flow with limit

Evaluations

Sustainability• Ecological - Reduce waste going into

environment• Economic - Potential marketable products

•Biodiesel•Protein•Fertilizer

• Social/Ethics•Aesthetics (smell), Bug cruelty (3 Rs)•Changing household ideologies to

reduce the amount of wasted food

Budget/Economics

Bill of Materials

Evaluation of AlternativesFed Batch System Continuous System

Aeration N/A Aerated Non-aerated

Mass Reduction 43% 43% 43%

Space ~ 50 m2 ~ 13 m2 ~ 34 m2

Winterization Possibly Yes(air flow control + insulation)

Yes(air flow control + insulation)

SS viability Nonexistent Theoretical Probable

Costs ~ $14,000 ~ $1530 ~ $2800

ROI 19 years 2.5 years 4.5 years

Evaluation of AlternativesFed Batch System Continuous System

Aeration N/A Aerated Non-aerated

Mass Reduction 43% 43% 43%

Space ~ 50 m2 ~ 13 m2 ~ 34 m2

Winterization Possibly Yes(air flow control + insulation)

Yes(air flow control + insulation)

SS viability Nonexistent Theoretical Probable

Costs ~ $14,000 ~ $1530 ~ $2800

ROI 19 years 2.5 years 4.5 years

Conclusions• Goal achieved:

•Reduces mass by 43 %, converts rest to marketable products

• Costs: •$1530 overhead•$25 per day on labor•$1.40 per day on electricity

• Sustainability:•Reduces amount of waste going to

landfill

ConclusionsQuestions Answered

• User•What type of training will I need to operate this

system?•What type of maintenance will the system

require?•How frequently will the system parameters

need to be checked?• Client

•What is the expected return on investment?•How consistent do the system conditions need

to be?•How consistent are the properties of the

products?• Designer

•What state will the food waste come in as?•How much waste will come in per day?•What, if any, systems already exist to address

the problem?

Timeline

References• American Biogas Council. 2015. Frequent Questions. American Biogas Council. https://www.americanbiogascouncil.org/biogas_questions.asp. Accessed November 2015.

• Appels, L., J. Lauwers, J. Degreve, L. Helsen, B. Lievens, K. Willems, J.V. Impe and R. Dewil. 2011. Anaerobic digestion in global bio-energy production: Potential and research challenges. Renewable and Sustainable Energy Reviews. 15(9): 4295-4301.

• Aubrey, Allison. 2015. It’s Time To Get Serious About Food Waste, Feds Say. NPR. Available at: http://www.npr.org/sections/thesalt/2015/09/16/440825159/its-time-to-get-serious-about-reducing-food-waste-feds-say. Web accessed 16 September 2015.

• Binh Dinh, 2012. https://binhdinhwssp.wordpress.com/tag/binh-dinh/. • Briggs, Justin. 2013. US Food Waste. Food Waste. Stanford University. http://large.stanford.edu/courses/2012/ph240/briggs1/.

Accessed Nov 2015. • Cornell Composting. 1996. The Science and Engineering of Composting. Cornell Composting Science and Engineering.

Cornell Waste Management Institute. http://compost.css.cornell.edu/science.html. Accessed November 2015. • Gillooly, J.F., J.H. Brown, G.B. West, V.M. Savage and E.L. Charnov. 2001. Effects of Size and Temperature on Metabolic

Rate. Science. 293(5538): 2248-2251. • Houg, R. T. 1993. The Practical Handbook of Compost Engineering. Boca Raton, FL: Lewis Publishers. • Larson, Judd, Sendhil Kumar, S. A. Gale, Pradeep Jain, and Timothy Townsend. "A Field Study to Estimate the Vertical Gas

Diffusivity and Permeability of Compacted MSW Using a Barometric Pumping Analytical Model." A Field Study to Estimate the Vertical Gas Diffusivity and Permeability of Compacted MSW Using a Barometric Pumping Analytical Model. N.p., 2012. Web. 22 Nov. 2015.

• Liu, Q., J.K. Tomberlin, J.A. Brady, M.R. Sanford and Z. Yu. 2008. Black Soldier Fly (Diptera: Stratiomyidae) Larvae Reduce Escherichia coli in Dairy Manure. Environ. Entomol. 37(6): 1525-1530.

• Michigan Farm Bureau. Frequently asked questions about Anaerobic Digesters (ADs). https://www.michigan.gov/documents/mda/MDA_AnaerobicDigesterFAQ_189519_7.pdf.

• Nespolo, R. F. "Intrapopulational Variation in the Standard Metabolic Rate of Insects: Repeatability, Thermal Dependence and Sensitivity (Q10) of Oxygen Consumption in a Cricket." Journal of Experimental Biology. 206.23 (2003): 4309-315. Web.

• Olivier, Paul A. 2004. Disposal apparatus and method for efficiently bio-converting putrescent wastes. US 6780637 B2.• Ritika, Pathak, and Sharma Rajendra. "Study on Occurrence of Black Soldier Fly Larvae in Composting of Kitchen Waste."

International Journal of Research in Biosciences 4.4 (2015): 38-45. Web.• Vermivision, 2012. http://vermivision.net/?page_id=2• Zucconi, Franco, Antonia Pera, Maria Forte, and Marco De Bertoldi. "Evaluating Toxicity of Immature Compost." BioCycle 22.2

(1981): 54. Web.• Wightman, J. A., and M. Fowler. "Rearing Costelytra Zealandica (Coleoptera: Scarabaeidae)." New Zealand Journal of Zoology

1.2 (1974): 225-30. Web.

Questions?