Utilization of University Food Waste

Joseph Hummer * Cassidy Laird * James Rogers

Introduction:Recognize & Define Problem●Clemson University

○# People (Ballpark ~30,000)○ Lots of waste

●Food waste○ Dining Halls, food courts

○ # of meal plans (~8000)○ ~ 220 tons/year○ Composting in place

Define GoalsBiological

Design process to reduce amount of final ‘waste’For now, consume 285 lbs food waste a day

Viable products to offset time/costsStructural

Can fit within campus infrastructureOthers to be determined

MechanicalTo be determined - depends on systemAugur 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●Traditional Composting●Anaerobic Digestion●Black Soldier Flies

Traditional Composting●Static pile composting●Pros:

○Easy to maintain○Fertilizer

●Cons:○Very lengthy process○Not efficient reduction of waste○Releases methane

Anaerobic Digestion●Decomposition through anaerobic

microorganisms●Pros:

○Production of biogas○Faster than static composting

●Cons:○Keeping it anaerobic ○Higher costs - labor, implementation

Black Soldier Flies●Food consumption 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 )℉

Governing Equations●Mass balances:

○Waste in → waste out○All three composting methods

●Growth rates (Monod Model)○Detritivores

■Microorganisms for compost & anaerobic■Insects for BSF

●Thermodynamics/Heat Transfer○Possible heat generation○Specific conditions

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

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

Questions