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Cow Windmill
Power from cow farts without creating carbon dioxide | |
Cows generate up to 1000 liters a day of flatulent gases. This invention would see that some of this 'free energy' is put to use.
A small propeller with turbine is attached to an arm and harness sticking out the backside of cow. The propeller is positioned 'downwind', but not so close as to be in
danger of pooification.
The turbine is connected to a rechargeable battery pack slung over the back of the cow. When the cow comes in for milking, the battery pack is swapped out with another, and the charged battery is plugged in to power various items on the farm.
Cow Destroys The Planet
http://www.dailymai...climate-change.html [Amos Kito, Jul 27 2008]
Power Cows
http://jeq.scijourn...t/figsonly/32/1/269 [2 fries shy of a happy meal, Jul 27 2008]
The rest of the cow fart related ideas.
http://www.halfbake...energy_3a_20Methane Hey, if a joke is good once, it'll be ten times as good if you repeat it ten times, right? [jutta, Jul 27 2008]
[link]
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You've put the turbine on the wrong end. [Link] |
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[-] you intend to waste the gas to atmosphere after turning the propeller. if the gas has heat value, collect it using some automatic vacuum system & derive useful energy by burning it. |
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The mixture is not adequately rich to allow any real use. |
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It's nice to see that someone is actualy trying to harness the energy. |
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Gas fractionating is not as simple as it seems. |
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Could not find a direct source for the concentration of methane in a cow fart. Here's what I did. |
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various sources:
cow farts 10kg methane a year
cow farts 800 liters volume per day
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That's 292,000 liters per year. Density of methane is 6.67*10^-4 g/cm^3. There is 1.5*10^7 cm^3, or 15,000 liters of methane in a year of farts. |
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15,000/292,000 = 5.13% methane in the farts. |
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Wikipedia says the gas is flammable only between 5 and 15% in air. |
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These calculations suggest that you are wrong, [WcW]. No fractionation is required as the gas will usually be combustible in it's native concentration. |
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The vast majority comes out the mouth. |
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Yes but still worthless as a fuel as it would be impossibly bulky to store at that concentration. Even more important if used to power a generator that is only 60kWh per YEAR (at a comical assumed efficiency). We could debate the merits of fuel concentration (less is bad) but the simple fact that a few pounds worth of dried dung yields the same quantity of energy should help make clear the basic point. The issue is not that farting yields a vast untapped resource but that it yields an additional green house gas. Also that cows are a huge waste of the food that they consume thus that it should be otherwise worthless (unless you like turning nice food into very flammable farts and dung). |
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//without creating hydrocarbons// |
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WTF? The burps and farts are mainly methane. Methane is, practically, a hydrocarbon. |
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Maybe that's meant to say "without creating carbon dioxide", by avoiding the burning of said hydrocarbon, in an effort to reduce greenhouse gasses. Well, methane is a greenhouse gas, and probably should be burnt into CO2 before it dissipates. |
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When I read this, it seems that the idea is to just use fart power to spin a windmill, just by blowing. Folks seen to be reading in an assumption that it burns the methane, and arguing that. I see only that it uses the force of a fart to power a turbine, much as humans use the force of a fart to lift blankets. Combustion and methane flammability are nowhere in it. The subtitle maybe should be "without burning hydrocarbons". |
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If this is the non-combusting Le Pétomane approach, I suggest that the rig should be converted to capture the power of the cow's breathing. A turbine hung over the nostrils should get a lot more breeze. |
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No, we were working off a previous anno: //if the gas has heat value, collect it... & derive useful energy// |
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[WcW] //Even more important if used to power a generator that is only 60kWh per YEAR (at a comical assumed efficiency)// |
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Yes, it is comical if you have read too much between the lines. Simply consider a burner system (may be similar to domestic one) to burn gas for heating purpose i.e. a fully baked PNG (Piped Natural Gas) system. |
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I doubt that a system mounted to a cow would achieve an efficiency btu/kWh comparable to a generating plant. 60kWh is far less than the cow could be made to produce turning a mill for a single day. |
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Well yeaaah. But they fart and burp without training. |
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I like the battery swap out - how about a jersey of thermocouple tiles . Keep the cow warm and dry and charge batteries .
How much heat does a cow put out ? |
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Yes , a Peltier matrix coat for cows . |
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I think you'd have better luck putting the herd all in some kind of air-tight-ish barn where the ventilation is scrubbed for the hydrocarbons (could also use the hot gas as a heating source), which are then refined and then used as a fuel source elsewhere. moooo. |
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You'd probably generate more energy by either strapping a windmill to the back of the cow, or harnessing the power of her tail. |
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I remember a movie about hog emissions where they were kept in a thunderdome. |
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