Archive for August 2010
Colorado State University Professor Developing Anaerobic Digester to Reduce Cost of Waste Disposal, Particularly in Western States
A Colorado State University professor is developing an anaerobic digester that turns animal waste into methane using much less water than conventional technology, making it more economically feasible and easier for use by feedlots and dairies in Western states.
Anaerobic digesters are often applied at large animal feeding operations elsewhere in the country, largely in the Midwest or on the East Coast, because of the abundance of water resources, said Sybil Sharvelle, assistant professor of civil engineering. High liquid content waste is required by existing technology to enable pumping and mixing of the waste in addition to stimulation of the growth of microorganisms that convert waste into methane.
“In the arid West, you pay for water rights, so water use is very controlled and there’s a financial motivation for producers to conserve water, which is why management practices are different,” Sharvelle said.
Sharvelle and her graduate student, Luke Loetscher, are collaborating with Fort Collins, Colo.-based Stewart Environmental Consultants Inc. and the university’s Agricultural Experiment Stations to evaluate the feasibility of anaerobic digestion at Colorado feeding operations. She has an Extension appointment to help tackle issues related to agricultural waste throughout the state of Colorado.
Stewart Energy, a wholly owned subsidiary of Stewart Environmental Consults in Fort Collins, is working to commercialize the process and has an exclusive option to license the process from the Colorado State University Research Foundation, or CSURF.
Forbes Guthrie, CEO of Stewart Energy, said, “This process addresses a significant and underserved market of energy production from low-moisture biomass. In addition, the process will ultimately help the agricultural community to meet more stringent environmental regulations with regards to both air and water emissions and, at the same time, provide the operations with stable and predictable energy costs for multiple years in advance.”
Sharvelle’s system is unique because it separates the digestion process into two major steps. How it works: Water is trickled over dry waste in a vessel to capture organic materials and convert nearly 60 percent of the solid material into liquid organic acids. The liquid is put into another reactor which is heated to incubate the bacteria living in the digester. These bacteria then convert waste into methane.
That separation of processes also assists Western farming and ranching operations that must contend with rocks and sand in the waste when they scrape it from their lots. These materials are detrimental to operation of conventional anaerobic digestion technology. With Sharvelle’s system, remaining solids from the first step – known as hydrolysis – are separated and can be composted.
“Feedlots are huge and they produce a lot of manure, and the compost they produce is usually more than the area around them has demand for,” Sharvelle said. “Feedlots are often located in areas where there is not a lot of fertile farmland, so they’re ending up with this extra waste material that there’s nothing to do with.”
The methane produced in the digester can then be used as a source of energy to run a generator and used in a natural gas pipeline once byproducts such as carbon dioxide are removed.
Biological processing through anaerobic digestion became common practice with wastewater treatment in the 1960s and 1970s, Sharvelle said.
Sharvelle is based in the College of Engineering. Her research interests include biological waste processing, water reuse and sustainable water and waste management. She also contributes to the CSU Institute for Livestock and Environment with the goal of finding practical, economical solutions to minimize environmental impacts from the livestock industry.
Biodigester That Turns Manure into Methane Demonstrated at Farm Science Review
Farmers interested in alternative energy technologies for the farm can learn more about the small-scale biodigester developed by Ohio State University ecological engineers. The technology will be demonstrated at Farm Science Review, Sept. 21-23 at the Molly Caren Agricultural Center in London, Ohio.
Jay Martin, a researcher with the Ohio Agricultural Research and Development Center, has developed a modified fixed-dome digester that can make methane from manure, which can either be burned as an alternative to natural gas or propane, or converted to electricity using a generator. The 300-gallon biodigester, installed at Waterman Agriculture and Natural Resources Laboratory in Columbus, is designed specifically to cater to average-sized and smaller livestock farms – around 150 dairy cows on average.
“There are less than 200 digesters working on livestock farms in the United States, and those digesters are designed for large-scale industrial dairy operations in the range of 10,000 or 15,000 head. And they are expensive – around $1 million to implement,” said Martin, who is also an associate professor with the Department of Food, Agricultural, and Biological Engineering. “Right now, only farms with around 1,000 cows or larger can use digesters. You crunch the numbers and more than 95 percent of the livestock farmers in the U.S. can’t use this technology to create renewable energy.”
Recognizing the need for smaller-scale, affordable biodigesters, Martin and his colleagues turned to technologies widely implemented in China, India and South American nations like Costa Rica, and adapted a biodigester for Ohio’s climate.
The result is a biodigester that can generate 500 liters of biogas a day — 60 percent methane and 40 percent carbon dioxide. For now, 10 gallons of manure is added per day, and the renewable energy generated is enough to cook a few meals.
The biodigester technology being demonstrated at Farm Science Review is a mini version (about 5 gallons) of the Waterman model. The mini biodigester can create enough biogas to roast a few marshmallows.
Martin said that the technology being demonstrated is the first step in determining how successful biodigesters can be on Ohio dairy farms.
“One of the challenges of a biodigester is the air temperature. The microbes that turn the organic matter into biogas are sensitive to colder temperatures,” said Martin. “How the biodigester performs in winter will aid in determining if such technology can be successful in Ohio.”
The Waterman biodigester was installed last October and researchers, including graduate students Richard Ciotola and Juan Castano, began monitoring biogas generation this spring. If successful, Martin envisions scaling up the biodigester to 5,000 or 10,000 gallons.
“A thousand-gallon biodigester is probably the minimum right now that a farmer would need to get up and running, and the smaller-scale is much more affordable – about $100 per cow for the system,” said Martin. “The key to the design is based on optimum amount of manure that can be collected per day for the greatest amount of biogas produced.”
Researchers are still exploring minimum and maximum manure loads that the 300-gallon biodigester can handle. Too little manure, and not enough biogas is created. Too much manure, and the pH drops, killing off the microbes that create the biogas.
Martin envisions farmers using biodigester technology in such applications as heating water for cleaning milk parlors. In addition, through the conversion process of manure to biogas, the displaced liquid – rich in inorganic nitrogen and phosphorus – can be applied to field crops as fertilizer.
The mini biodigester model will be on display at Farm Science Review in front of the Firebaugh Building on Friday Avenue in the exhibitor area. There will be daily demonstrations of how the technology works.
Source : Ohio State University
Cow Power? County to unveil biogas pipeline proposal to convert farm waste into electricity
On Tuesday, Aug. 31, legislators will meet with members of the county department of planning and economic development, area dairy farmers and Cornell experts to discuss the feasibility of building a pipeline in Cayuga County to transport biogas and convert it into useable energy.
“This is one of only a few projects like this in the country,” said Frank Howe, a county planner working on the pipeline project. “It has garnered a great deal of attention and we’re being watched by the USDA in Washington as a model for the dairy industry in the U.S.”
Biogas is a mixture of mostly methane and carbon dioxide produced by the breakdown of organic material by bacteria. Many farmers produce the gas as a way to save on energy costs and reduce the smell of livestock waste.
The proposed 40 miles of pipeline would connect seven dairy farms on the south end of the county industrial park on West Genesee Street Road in Aurelius.
Special anaerobic digesters on each farm would extract biogas from cow manure and then send the gas through the pipeline to a generator facility where it could be converted to either electricity, heat or natural gas.
Kettering University Unveils Biomethane Powered Truck
It may be a white Chevy Silverado, but it represents the future of green in Flint.
Kettering University, officials from Swedish Biogas International, Flint Mayor Dayne Walling and others unveiled Flint’s first biomethane fuel truck during a ceremony in front of Kettering’s Academic Building on Thursday, Aug. 19.
Students, working with faculty members at Kettering, have converted a 2500HD Chevy Silverado to run on a dual-fuel system. The vehicle can be powered by biomethane gas, a renewable alternative fuel that will be produced at the new biomethane plant in Flint.
To accomplish this dual-fuel use, Kettering called on one of its alums to help out. Rebecca Royer ’81, owner and president of Baytech Corp., installed a kit in April that allows the biofuel truck to run on both natural gas and gasoline. The natural gas is stored in a tank in the truck bed and is piped into the engine bay, ending at the top of the engine.
The on-board computer switches automatically between gasoline and natural gas while driving. Because the composition of natural gas and bio-methane are so similar, the truck should run well with bio-methane in the tank instead of natural gas, said student Nolan McCann, research assistant to Brenda Lemke and Dr. Ahmad Pourmovahed, professor of Mechanical Engineering.
Kettering researchers plan to run the vehicle on the bio-methane produced from the Flint Wastewater Treatment Plant and Swedish Biogas project. The Swedish Biogas Project will produce alternative energy from waste removed from the city’s wastewater treatment plant. The project is a collaboration of Swedish Biogas International (SBI), Kettering University, and the city of Flint, with support from the C.S. Mott Foundation, Swedish agencies, and the Michigan Economic Development Corporation (MEDC).
Rwanda: Schools to Shift From Firewood to Biogas
In an effort to promote the use of environmental friendly energy in the country, the government will finance the construction of biogas facilities in the three major schools of the Southern Province, to a tune of Rwf192m.
The three schools will be the pilot centers before the programme is rolled out to schools across the country.
The three schools include; St. Joseph Kabgayi, Ecole des Sciences Byimana, and Notre Dame de Lourdes, all located in Muhanga and Ruhango districts.
