Black Soldier Fly Digestion of Food WastesJoe Hummer, Cassidy Laird, James Rogers

19 October, 2015

Introduction: Recognize & Define Problem●Americans waste ⅓ food

○133 billion pounds/yr (513 Tg)○National food waste limit1

●Clemson University○Same situation○30,000 people○220 tons/year (200,000 kg)○Composting in place

http://www.clemson.edu/administration/pre-collegiate/facilities/dining.html

Define Goals

BiologicalDesign process to consume 130 kg food waste a dayViable products to offset time/costs

StructuralCan fit within campus infrastructure (Cherry Crossing)Batch or CSTR/PFR

MechanicalHeater and/or fanAugur or stirrers

Constraints/Considerations●Constraints

○Skills, time, Space, costs○Want to be able to implement○Equipment

●Considerations○Safety, ultimate use (LCA)○Sustainability○Ecological - Climate/weather, possible impacts

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 period for the cost of the system?○ How consistent does the system conditions need to be?○ How consistent are the outcome of 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 this problem?

Literature Review: Possible Solutions●Static pile

composting●Pros:

○Easy to maintain○Fertilizer

●Cons:○Very lengthy process○Not efficient

reduction of waste

●Anaerobic Digestion

●Pros: ○Production of biogas○Faster than static

composting●Cons:

○Higher costs - labor, implementation

■Aqueous system

Black Soldier Flies●Decomposition through detritivorous insects●Pros:

○Lipids for biodiesel○Fertilizer, proteins○Reduces waste amount significantly

●Cons: ○fairly new, not as much literature○Composition varies with diet○Requires warm environment (around 80 )℉

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

Existing System4 pods that hold 85 lbs of food eachconsumes 25 lbs of food per pod per dayproduces 1 lb of BSF per day (on average)

Possible Design ConsiderationsContinuous compostingYear round operation (winterize)Food waste homogenizerAerationManual egg inoculation (plug flow)Rotation/MixingLeachate

Governing Equations

● Growth rates ■Gompertz Growth Rate

Sigmoidal growth bestreflects experimental data

k = growth constanta = k*inflection timeb = k

Winsor, 1931Banks, Gibson, Cameron 2014

Growth Rate Continued

● Derivative correlates to appetite?

Governing Equations●Mass balances:

○Rate of accumulation = waste in - waste out + rxns

In the case of BSFsFertilizer accumulation = food waste in - food reduction by BSFs (reaction by BSFs)

Product accumulation = growth of BSFs

Mass Balance ContinuedFeeding rate affects:

decompositiongrowthBSF compositionEfficiency

Fertilizer Production?Lack of dataResearch nutrient concentrations

grams of food waste in batch digester over time

Governing Equations● Thermodynamics/Heat Transfer

○Heat generation○Specific conditions

●Thermal Energy Balance

●STELLA

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

Design Methodology & Materials: Analysis of Information

Chose black soldier flies - whyIdentify knowns/given parameters:

amount of food put in (130 kg per day)Need an efficient system (constant 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 of some sortMoisture contentRamp slope/roughnessFeeding rate

Synthesis of DesignContinuous modelSigmoidal Growth modelMass balance to determine:

Amount of pupae grown (weight)Amount reduction

Energy balance For winterization

Insulation and/or fansNext step to begin reactor design

Volume and retention timeMixing

Alternative Design OptionsPlain batch - many existing systems use thisContinuous

difficulty of how to include ramp for self-harvestPFR/modular - vertical composter idea, ‘pencil’ idea

https://www.google.com/patents/US6780637http://www.intergeo.com/en/industry/products_services/waste_management/X_Act_Rotating_Compost_Drums.html

http://www.agnet.org/library.php?func=view&id=20110804103107&type_id=2

Engineering Principles IncorporatedAssuming Continuous model:

Food input desired - 130 kg per dayRestrictions - 23-43 °C

Consider mass and energy balances, growth ratemass→amt reduction 50-60%, amt pupae 3.36 kg (1.00 kg oil, 1.34 kg

feed)energy → air flow rate of 1.2 kg/s

Digester design - V = 377 L, tau = 20 daysCurrent daily yield:

will complete in future, for now, with oil, protein, fertilizer, landfill savings $10/day

Overall: Not very lucrative, but the process is not even close to optimized

How Constraints HandledBiggest difficulty was finding info/sources with relevant

data

Difficult to find exact models Approximate model based on little data

Difficult to find sample dataNo data on metabolism, growthWaste reduction throughout lifeUse manure dataFind overarching trends and approximate

Sustainability●Ecological - Reduce waste going into

environment●Economic - Potential marketable products

○Composting - fertilizer○Anaerobic digestion - biogas○BSF - biodiesel, protein, fertilizer

●Social/Ethics○Aesthetics (smell), Bug cruelty (3 Rs)

Timeline

ReferencesWinsorhttp://www.pnas.org/content/18/1/1Banks, Gibson, Cameronhttps://researchonline.lshtm.ac.uk/1917781/1/2014_ITD_PhD_Banks_IJ.pdfDiener, Zurbrugg, Tocknerhttp://wmr.sagepub.com.libproxy.clemson.edu/content/27/6/603

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.

Clemson Composting Creative Inquiry. 2012. Clemson Dining Hall Food Waste Study. Available at: https://clemsoncomposting.wordpress.com/2012/12/13/499/. Accessed 6 September 2015.

EPA. 2013. Waste materials densities data. Victoria, Australia: Environmental Protection Agency Victoria. Available at: http://www.epa.vic.gov.au/business-and-industry/lower-your-impact/~/media/Files/bus/EREP/docs/wastematerials-densities-data.pdf. Web accessed 21 September, 2015.

ESR International, LLC. 2008. Bio-Conversion of Putrescent Waste: A Beneficial Arthropod. Available at: http://www.esrint.com/pages/bioconversion.html. Accessed 2 September 2015.

Executive Office of Energy and Environmental Affairs. 2015. Home Composting Tips: A Guide to Composting Yard and Food Waste. Available at: http://www.mass.gov/eea/agencies/massdep. Accessed 2 September 2015.

ReferencesGustavsson, J. 2011. Global Food Losses and Food Waste: Extent of food losses and waste. Food and Agriculture Organization of the United Nations. 4-10.

Kim, W., and Bae, S. 2011. Biochemical characterization of digestive enzymes in the black soldier fly, Hermetia illucens. Journal of Asia-Pacific Entomology. 14(1): 11-14.

Li, W., Li, M. 2015. Simultaneous utilization of glucose and xylose for lipid accumulation in black soldier fly. U.S National Library of Medicine 8(117): doi: 10.1186/s13068-015-0306-z.

Newton, L., Sheppard, C., Watson, D. W., Burtle, G., and Dove, R. 2005. Using the black soldier fly, Hermetia illucens, as a value-added tool for the management of the swine manure. Director of the Animal and Poultry Waste Management. 4-14.

Ngoc, U. N., and Schnitzer, H. 2009. Sustainable solutions for solid waste management in Southeast Asian countries. Waste Management. 29(6): 1982-1995.

Parfitt, J., Barthel, M., and Macnaughton, S. 2010. Food waste within food supply chains: quantification and potential for change to 2050. The Royal Society. doi: 10.1098/rstb.2010.0126

Popa, R. 2012. Enhanced ammonia content in compost leachate processed by black soldier fly larvae. U.S National Library of Medicine 166(6):1381-7. doi: 10.1007/s12010-011-9530-6.

Risse, M., and Faucette, B. 2012. Food Waste Composting: Institutional and Industrial Application. UGA extension.

University of Georgia. 2005. Using the black soldier fly, Hermetia illucens, as a value-added tool for the management of swine manure. Tifton, GA: University of Georgia.

Yue, B., Chen, T., Gao, D., Zheng, G., Liu, B., and Lee, D. 2008. Pile settlement and volume reduction during forced-aeration static composting. Bioresource Technology 99(16):7450-7457.

Questions