| Project Description: I am building a small anaerobic digester that will be tested with the intention of determining if methane yields would be sufficient enough to create methane for cooking and space heating fuel. Small Scale digesters are not commonly used in Developed Countries. The developing countries where small digesters are used are generally in warm environments. I plan to construct this digester in Trade, Tennessee at a local restaurant called Sharpies. This colder environment is an unusual place to implement a small scale digester. In some circumstances heating requirements of a digester for adequate methane harvesting can sometimes outweigh the benefits of the methane recovered. My design implements the use of a solar thermal panel to generate heat to keep the digester contents at the appropriate 95 degree temperature for high methane yields. Locating the panel lower than the digester will enable the system to thermosyphon, eliminating the need for an expensive solar thermal pump. The digester tank will be buried so that the external temperature is not a variable.
Food waste from restaurants is known to yield three times more methane than manure. Manure and sewage sludge are the most common feedstocks for anaerobic digestion. Utilizing the daily foodwaste output of 50 lbs. could potentially yield enough methane for cooking and water heating for this small restaurant. Perhaps we will discover that space heating may be an option, as well. Many of the materials needed for the research are being donated by the restaurant owner, however there is a still a great need for finances to implement the solar thermal aspect of the project. An old solar thermal that needs refurbishing is being donated, but I am still in need of piping for the solar thermal system and the digester's heat exchanger. I am also measuring the methane yields with an instrument that is being donated. |
