What is it?
The Grass-to-gas project is a 5-year, USDA-funded project that carries out research, extension, and education programs aimed at developing new approaches to Anaerobic Digestion that are economically beneficial to farmers and ecologically beneficial to farms.
The project is led by Iowa State University and Penn State University, with a team of partner farmers and companies all working together to grow this opportunity.
Demonstration Farms, where perennial grass production, cover crops, and their use in biogas …
Professor and Extension Economist
Agricultural Engineer in the Department of Biological and Environmental Engineering at Cornell University
Phone: (607) 255-2088(607) 255-2088
Fax: (607) 255-4080
Table of Contents
Anaerobic Digestion Nutrient Transformations
Anaerobic digestion (AD) is the process in which organic compounds are broken down by naturally occurring bacteria, including methanogenic microorganisms under oxygen free conditions, transforming organic matter into biogas (methane (CH4), carbon dioxide (CO2), water vapor, ammonia, and hydrogen sulfide) (Dugba and Zhang, 1999; AgSTAR, 2010b). The end products of this process include biogas, a renewable …
Anaerobic digestion is a manure treatment system that produces biogas. There are many benefits of digestion such as reductions in: odor, pathogens, and greenhouse gases (climate change). Producing biogas from manure yields useful by-products. The economics of digestion are dependent on state energy policies and co-digestion of off-farm wastes to generate revenue.
Cayuga County Regional Digester (New York)
This virtual tour highlights the Cayuga County Soil & Water Conservation District regional digester. This facility receives …
Most references on bomb calorimeter studies of manure indicate about 7,500 BTU/lb of manure dry matter. This value is similar to the energy in raw feedstuffs. One finishing pig will consume about 600 lb of feed. The energy content of the feed is about 5 million BTU. The pig will excrete about 150 lb of manure dry matter. Energy content of the manure is about 1 million BTU.
The water in manure must be vaporized before the manure will burn. …
When manure is anaerobically digested, the biogas produced is primarily composed of methane and carbon dioxide, with lesser amounts of hydrogen sulfide, ammonia, and other gases. Each of these gases has safety issues. Overall, biogas risks include explosion, asphyxiation, disease, and hydrogen sulfide poisoning.
Extreme caution is necessary when working with biogas. Adequate ventilation, appropriate precautions, good work practices, engineering controls, and adequate personal protective equipment will minimize the dangers associated with biogas. Wherever possible, …
Biogas generated from anaerobic digestion processes is a clean and environmentally friendly renewable fuel. But it is important to clean, or upgrade, biogas before using it to increase its heating value and to make it useable in some gas appliances such as engines and boilers.
While most large farms use their biogas for heat and power, it is worthwhile to consider all the options before deciding which path to take, including direct sale of biogas to an …