Anaerobic Digester & Food Waste Management Lead Contact: Ashley Waldron BS CE 12 (Email: waldroae@clarkson.edu) Project Team: Tom Cruger Executive Chef (Email: Cruger-Thomas@aramark.com) Flavia Kobusingye E&M 12 (Email: kobusif@clarkson.edu) Request Budget Amount: $4877
Problem Need At this time, all of the food waste generated by Clarkson University is simply thrown into the trash and transported to a landfill, wasting all of its potential value and energy. However, it does not have to be this way; there is a $300,000 anaerobic digester sitting on campus that has the potential change the way our campus treats its food waste. A food waste management plan needs to be implemented in order to efficiently quantify, collect, and transport the food waste on campus to this digester. Once there, the anaerobic digester will process the food at 650 gallons per day, create methane gas that is converted into electricity and heat, and produce great quality fertilizer. This project is will have a significant positive impact because it reduce our waste and waste costs significantly, generate renewable energy, decrease fertilizer costs, and create more opportunity for research. Project Approach The objective of this project is to establish a food/organic waste collection system at the Ro-Bro cafeteria to initiate the use of the University s anaerobic digester. Results of this pilot program can then be used to expand it to other major food service locations around campus. In order to ensure success of this project, a detailed course of actions has been laid out. To give a quick overview of the system, staff at the food serving locations will be educated about the process, and pre-consumer separation (i.e., in the kitchen) will begin. Extensive advertising will be done about the program around campus to increase student s awareness. After a week of piloting the pre-consumer separation, post-consumer separation (i.e., in the cafeteria) will start. An assessment of the data collected during the piloting will determine how many food waste containers will be purchased. Food waste will be carried in plastic bags and then placed inside 32 gallon bins at the loading dock near each food facility on campus. The containers will be transported and emptied into the digester twice a day, once before breakfast and once after lunch. The project team and leader will be working together to monitor the process and carry through many of the tasks. The more specific details of the project have been organized below into the four main tasks: 1. Quantify the food waste The food waste generated by Ross-Brooks and Empire Diner will be analyzed first though this proposed effort in order to develop an effective collection and waste transportation system. Data about the quantities of food waste, both pre-consumer and post-consumer, will be collected with the support of the Aramark staff over a period of two weeks. Usually, an employee will tie up a bag of trash when it is full, send it down stairs using a dumbwaiter, carry it to the nearby dumpster and empty it there. This process with be modified slightly, starting with the purchase and use of 2-3 extra bins that will be used for separated food and some paper products for the digester. All managers of Ro-Bro and Empire Diner will be taught exactly which substances can go into the food waste bins and which must go in the trash bins. The managers will pass that knowledge off to their staff, at which time pre-consumer separation can begin. The staff will measure and record the weights of the bags of pre-consumer food waste followed by another week of weighing the separated post-consumer waste. From the data collected, we will obtain an average weight of food waste per bag, average weight of food waste per meal, and average weight of food waste per day. From these numbers we will calculate how many 32 gallon containers we will need to purchase to store the waste between pick-ups. During the two week period, members of our project team will open randomly chosen bags and analyze its composition to ensure that the waste is being separated correctly. Tom Cruger and his staff drastically changed the composition of the post-consumer trash from previous years by taking all of the plastic utensils, cups, and plates off the shelves. Thus, only potential non-food items that could go into the waste container are napkins, which can go
into the digester. Between the two week data collection and random bag checks, the process of separating waste will have been developed and sufficient data collected for the design of the food collection and transportation systems. 2. Collect the food waste The collection of post-consumer food waste will begin during the second week of the data collection period. All students and employees will continue to separate their trash even after the data collection period is over. When the separation process begins, the waste bins will all be labeled as either food waste or trash waste. Besides the few extra 32 gallon trash bins for the kitchen, no extra equipment or supplies will be necessary inside the building because the separation requires so little change. In fact, both students and employees are already familiar with how to separate their waste. Students scrap off their plates with their utensils into a trash bin, empty their cups in a large container, stack their cups, and hand their dining-ware to the employee operating the dishwasher. Throughout the process, members of the project team will randomly select bags to check, at least once a week, and any items separated incorrectly will be noted and brought to the attention of the parties that come in contact with the items. Commonly Misplaced Items posters will be created if the list grows too large. Once the anaerobic digester is operating, employees will switch from throwing out the trash bags in the trash bin outside to throwing them into one of the 32 gallon containers, similar to the ones shown above, except they will be colored green. The number of containers needed outside to contain the volume of food waste will be based upon the results of the data collection. 3. Coordinate the transportation and disposal of the food waste The 32 gallon bins for Ro-Bro will be stored outside by right side of the loading platform, in the empty space where the old trash bin used to be placed. A truck will be used to transport the bins from the loading platform, shown in the left, to the anaerobic digester by Cheel. The back door of the truck bed will be let down to load and unload the bins. A suitable truck will need to be found for this task and it will only need to be used for two hours a day. There are numerous trucks and vehicles owned by Clarkson that are capable of transporting these containers, only approval is needed. The containers will be transported and emptied into the digester twice a day, once before breakfast and once after lunch. Tom Cruger suggested these pick-up times because they will result with equally split food disposal volumes. A Clarkson employee, such as a student worker, would be paid for two hours work, one hour per pickup time. Once at the anaerobic digester the bins will be manually lifted and dumped into the digester opening during the pilot period. After the digester feasibility has been proven, an automated hydraulic lift will be needed to load the digester in a more convenient manner. Many waste commercial and residential containers are already designed to be handled by lifts, such as the ones on garbage trucks. One example is the lift that Purdue uses to lift the bins, flip the bins over, and empty them. A lift would be much safer, more reliable, and more efficient. To include this on our own system, a wider, funnel-shaped opening will be designed and added to the anaerobic digester s existing opening for accepting food waste. This would greatly reduce the amount of food
mistakenly dropped on the ground when emptying out the bins. Since the trash bins are widely used and mass produced, replacing them would be easy and affordable. Once a month, the container will be rinsed and washed out with a hose, to reduce bacteria growth. Before a lift is purchased, a platform of similar height to the one at Ross- Brooks will be constructed for use during he pilot phase of this project. It will be placed next to the digester s opening for food waste, to make lifting the bins from the truck up to it much easier. 4. Promote the campaign In order to educate the population of Clarkson about the new separation system, an elaborate advertising campaign will take place. There are multiple HDTV s, called the digital sign boards, around campus that accept advertisements for campus related events. Clarkson s TV station and radio station also accept guests to speak about campus activities. Placing notifications in the integrator and on letter size paper on doors, around campus hallways, and on bulletin boards are also very common ways to get the word out about events. On every table in Ro-Bro and Empire Diner there are napkin dispensers that have two sides of available advertising space. Tom Cruger has the template for them and will place advertisements for the separation system on them. He has also agreed to allow our team to hang posters around Ro-Bro and Empire Diner in order to inform the students. A Comments/Concerns box will be placed in both diners to allow students to give feedback to our system. A Powerpoint presentation will be created to educate watchers about the system and will be put on the big screen TV in the student center can be reserved and provide lots of publicity. All of these methods are completely free and extremely effective. Impacts & Assessment This program will dramatically reduce the amount of food waste sent to the landfill by the Clarkson campus. Even with only Ro-bro separating and diverting food waste to the digester, the system will greatly reduce the amount of money spent per year for trash removal. The reduction in trash reduces many other factors as well, such as: money spent on disposing costs, number of trips driven to the landfill, gallons of gas saved, CO 2 emissions saved, electricity generated, and so on. Many of these values will be calculated once the data is collected during the beginning weeks of the process. The expected operation rate of the anaerobic digester is 650 gallon per day. Using this operation rate, the following benefits will occur: 211 tons of waste diverted per semester $37,000 per semester saved per semester 19.7 trips saved to the landfill 3544 fewer miles driven per semester This project has the potential to pay for itself in savings after two weeks. Based on numbers and data given by the Ro-Bro staff, this volume of waste for the digester is absolutely within reach. The numbers can also reflect how many trips are saved by the 18 wheeler to the landfill, which is 90 miles away. The fuel use and greenhouse gas emissions saved by diverting this waste to a facility across campus instead of 90 miles away will be estimated in the future. The digester will produce biogas in its three 1,400 gallon reactors, which will be operated in series or in parallel. The engine, an ENI 20kW co-generation combustion engine, produces electricity and heat through
burning the produced biogas. The electricity and heat created will used on campus, thereby displacing natural gas and electricity that we would otherwise purchase. The goal of this project is not to just run a pilot program over a semester, but rather to lay the foundation for a lasting system that reduces and reuses our food waste to produce energy. It is in reality an investment, one that will pay for itself multifold in savings. This pilot will be phase one of the project and help develop the system into a smoothly run process. It will show that this school is absolutely capable of instituationalizing this process and benefiting from it as well. Like with all great, up and coming ideas, it starts out as a new step to learn, but then slowly becomes a way of life. Although it is not sustainable by generating its own money to run on, it does pay for itself by the savings in cost it creates. This proposal is only for Ro-Bro, but in phase two of this project, it will steadily grow to include other dining areas around campus, such as the Concrete Café and Java City. For phase two, which will be after the spring semester, all of the different steps to the process will be fully developed and the system will be able to run at the full capacity of 650 gallons per day. Project Management and Schedule The entire process will be coordinated by a new position created for this project called the Food Waste Collection Coordinator. This person would be in charge of overseeing the drivers, creating a schedule for the drivers and volunteers, communicating between parties involved (i.e., Aramark and student workers), collecting and organizing all data, and overall maintaining a smoothly flowing system. It will require about 10 hours of work a week for the 15 weeks of the semester. The project team that will be assisting the Food Waste Collection Coordinator will grow in size from interested students within the Civil Engineering and Engineering & Management Capstone Design classes. A budget of $3877 is requested to complete this project. Primary expenses include new bins for food waste collection, modification of the food waste entry location into the digester trailer to facilitate transferring food waste to the digester, and student time for organization and transporting food waste.
Budget: Capital Name Cost Per Justification Platform Materials $400 Need to build a platform at the digester, same height as the one at Ro-Bro to help life the trash into the digester, until a hydraulic lift is purchased and installed. Vehicle Use $210 $1.00/mile, one mile round trip, two times a day, 7 Funnel Addition to Opening of Digester days a week, 15 weeks per semester $300 The opening of the digester must be wider and angled to allow trash bins to be emptied into it Total for one semester $400 $210 $300 32 gallon bins (for indoor use). Two per food location. 32 gallon bins (for outdoor use). Eight per food location $29/bin $35/bin Project Supplies Extra storage needed inside for separation of waste. Three are currently needed. Needed to store waste outside between pickups. Can be lifted by person or hydraulic lift. Eight are needed. Fees for Services Student Grounds Workers $10/hr Needs to transport waste containers to digester twice a day, 1 hour per transport, 7 days a week, 15 weeks per semester. $87 $280 $2100 Food Waste Collection $10/hr 10 hours a week, 10 dollars an hour, 15 weeks per $1500
Coordinator semester. Need to pay someone to oversee the entire process, which includes: overseeing drivers, coordinating schedules, coordinating transport, all data collection, communicating with Aramark, etc. Total: $4877
Calculations Appendix: The estimated maximum number of tons of waste that can diverted from the trash next semester was calculated: We have the potential to save 211 tons of trash from going into the landfill next semester. The amount of money saved because of the reduction in waste was calculated as: Beyond just money savings, the number of saved trips by the 18-wheeler to the landfill 90 miles away was calculated, as well as miles saved: Assumptions: (source: Clarkson university Digester System, by Stefan Grimberg) (source: http://www.seas.columbia.edu/earth/abcpaperfinal.pdf) (source: http://www.clarkson.edu/sas/calendar.html) (source: Susan Powers)