The Use of Biogas at the Dickinson College Farm
by Hannah DelSordo* (Advanced Biofuels USA) In recent years, Dickinson College of Carlisle, PA, has been interested in innovative environmental practices that will improve the community and foster a hands-on learning experience for the students. In 2008, students and staff at the College Farm began experimenting with small scale biogas systems, mainly for demonstration and education. Later, in 2015, the use of biogas began to develop as a new 1000-gallon capacity biogas system was installed on the farm.
The gas produced by the biogas digesters has been used to heat cooking appliances and to fuel other heating systems, as well as some low power generators that are used on the farm. The use of this biogas has been a great success in contributing to Dickinson College’s goal of going carbon neutral, which it reached in 2020.
The college has done so through the purchasing of carbon offsets, to offset the expenses from cooling and heating, as well as from travel. Along with the offsets, there has been a big push to increase the efficiency of technology in buildings and encourage sustainable practices in student’s daily lives.
The Dickinson cafeteria encourages students to use specific portion sizes when ordering food to not produce that much waste, however, the food that does end up as waste goes to the College Farm. This waste, along with livestock manure, goes through a process of anaerobic digestion to produce biogas and effluent. The researchers at the farm have found that “co-digestion” of organic materials along with manure has yielded the most success. The effluent produced is used around the farm to fertilize plants, while the gas made of carbon dioxide and methane is stored and burned.
Tony West (Dickinson College ‘21), a senior biology major, conducted research with the farm in the summer of 2020. His main goal was to enhance the biogas system and conduct research on how to upscale the biogas digester. Part of his role was to extend the hose that came out of the digester, to expand the places on the farm that could obtain effluent. This was necessary to increase the fertilization of the crops as well as become storage for the large amounts of effluent they had been producing during the summer months.
This summer the farm also made an effort to increase gas storage. Tony was able to make biogas bags, using rubber for sealing, to store the gas emitted from the biogas digester.
Due to Covid-19 and the lack of students on campus during the summer, the farm turned from getting food waste from campus, and instead looked toward local businesses. The local brewing company Molly Pitcher contributed their food waste to the farm, along with Carlisle High School. The contributions were necessary as they allowed the farm to keep consistent production of the biogas throughout the summer farming months.
The plans of the Dickinson College Farm biogas digester project are to continue increasing the efficiency of the system and the storage, as well as to find more innovative ways to use the gas.
Students are also researching ways to extend the biogas digestion season through heating systems and furthering the use of biogas as engine fuel on the farm.
Sources: http://blogs.dickinson.edu/farm/biogas/ (includes VIDEO); Tony West (Dickinson ‘21)
*Hannah DelSordo expects her BA in International Studies and French from Dickinson College in 2022. She’s interested in doing public relations work for an environmental nonprofit.
Thanks to Dickinson College for the photos.
Household Scale Anaerobic Digesters (BioCycle Magazine)