two state programs designed to encourage farmers to install methane digesters, which capture methane gas that can be converted into electricity. In spite of these efforts, Minnesota farmers have been slow to adopt this technology.
This hesitancy may be due in large part to the significant upfront costs and low electricity purchase rates offered by utilities. Technical limitations of biogas production may also be a factor. Studies have indicated that profitable biogas production in Minnesota using current digester technology may be limited to large dairy operations (at least 300 cows) that collect manure by scraping rather than flushing. Profitable methane production requires a significant amount of manure to be gernated on-farm, and cows have been shown to have greater gas production potential than swine or poultry (measured in ft.3/animal unit/day).
A methane digester is reported to be the newest project at Green Meadow Farms. They produce methane and sell the methane gas to a company called North American Biofuels L.L.C. They take the gas and convert it to electricity. The manure will now be diverted into the digester before it goes into the treatment plant. By doing this they should also be able to cut down on the cost of the ferric chloride that they use in the treatment process.
Straus Creamery expects to generate up to 600,000-kilowatt hours per year, saving an estimated $6,000 in monthly energy costs. A digester is an airtight container that uses bacteria to break down manure. As part of that process, methane gas is produced and used to power electrical generators.
Progress is taking place, but more momentum is needed if the sector is going to make a significant contribution to greenhouse gas emissions in the next 10 years. Biogas digesters are not going to appeal to all. Biogas is one of those matters where results do not come immediately. It can take a
One great and as yet hardly tapped in the US, is the use for biogas is as a replacement for natural gas in our gas systems worldwide. Biogas must be very clean before it can be pumped into that system, to reach exacting natural gas distribution pipeline quality standards. It must be of the correct calorific composition for the local distribution network to accept. Carbon dioxide, water, hydrogen sulfide and particulates must all be removed if present.
Production of biogas is a mature technology, well established in many European countries. Experience in Sweden has shown that upgrading biogas for use as a transportation fuel, while a relatively new technology, can be done with high reliability and at reasonable cost. Even the sludge that comes out at the end makes an excellent fertiliser.
In the US concerns still exist about the production of biogas during the winter, costly dung collection arrangements, inadequate slurry handling systems and lack of outside financial help. These are even so just some of the constraints reported in the promotion of the program.
There are two great sites at which you can find out more about this developing subject and those are the electricity from methane digesters web page and the biogas digester web site. Take a visit now!
