Giving Up Oil, Turning to Cow Poop?

Until we stop eating meat anyway...
By Rachel Cernansky
Boulder, CO, USA | Tue Sep 29 13:30:00 GMT 2009

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Alternative Fuels | Biofuels | Electricity | Transportation | Waste Disposal

Until people stop eating meat and drinking milk, we will continue to have a lot of manure on our hands. Environmentally speaking, that's been a real problem, so it's about time that manure is turned into a resource rather than a waste we don't know what to do with. And it's starting—companies from Texas to Idaho to Washington are now using manure to generate electricity. And in the Netherlands, more than 90,000 homes have been powered by chicken poop (about 440,000 chickens, to be more precise) for over a year.

Basically, it goes like this: manure collected by sewage pipes that run under a barn is mixed with other food wastes and then heated in an anaerobic digester, where it is kept for five days. During that time, microbes are busy decomposing the manure, a process that produces methane gas which bubbles to the top and then runs into a diesel generator, where it is burned to produce electricity. Often, the liquids that are left over are used as fertilizer, and solids are processed to be used as bedding for the cows. (If you don't think that sounds nice, maybe think twice before ordering your next burger.)

Using manure for biogas puts a dent not only in our dependence on fossil fuels, but in our waste stream and greenhouse gas emissions as well—literally hundreds of thousands of tons of solid waste and methane, which is 25 times more potent a greenhouse gas than carbon dioxide. So instead of being released into the atmosphere, it gets trapped, turned into a resource, and becomes slightly cleaner in the process.

Watch the COOLFUEL episode where the crew powers themselves from Green Bay to Chicago on manure.

Related Posts:
How to Turn Dirty Cow Poop Into Electricity
Holy Cow! Manure-to-Biogas Could Generate 3 Percent of US Electric Demand
G-word: From Cow Manure to Money

Comment

I saw something on cable about each cow producing 50 pounds of manure per day. Think about how many cows there are in the US. Although I have heard that manure produces methane, which is a low quality gas, it can be burned and used to produce energy. Wonder what kind of gases are released from burning methane? CO2? Some manure is also used as fertilizer, of course, but theres plenty that could be used to produce methane? Wonder how much it costs to produce that methane from the digester?