Improving the efficiency of a manure digester through co-digestion of high-energy containing waste products
Mentor: Dr. Stefan Grimberg
Department: Civil and Environmental Engineering
Code: rp2006017
Clarkson University is leading a consortium that is actively researching waste, energy and profitability solutions for struggling North Country farmers and the dairy processing industry. By using cow manure to fuel anaerobic digesters, farmers and dairy processing facilities can displace purchased sources of heat and power, reduce wastewater treatment and environmental compliance costs, and mitigate exposure to fluctuating power prices. The Clarkson dairy waste partnership will design and build a state-of-the-art digester/energy recovery system at a working dairy/tourist showcase farm to educate farmers and the public about this technology. In addition, substantial data on the mass and energy flows to validate a computer model will be collected and used to optimize the system.
Due to the relative low energy content in manure, digesters may become uneconomical for smaller farms, especially in northern climates where maintaining the digester at 37°C presents a challenge. Supplementing the manure feed stream with an energy rich waste stream may be one possible way to improve farm digester economics. Possible energy rich waste streams generated at farms are waste silage, waste milk, glycerol from biodiesel manufacture or cheese whey from cheese manufacturing. While the latent energy content of the compounds is higher than that of manure unknown is the net increase in performance of a digester receiving a mixture of the input feeds.
The goal of this research is to determine the methane gas potential that is generated for various farm wastes. Generated data will be used in a developed digester process model to estimate the net economic benefit of treating the mixtures of waste material and compared to the base digester treating only dairy manure.
