I keep hearing about how cattle are a significant contributor to greenhouse gasses…
How much would all that methane be worth (gross) if we could harvest it somehow? I’m thinking just the U.S. but world figures are cool too.
How much per cow per year or day?
We should invent a balloon of some kind that lets poop out but retains the methane. Heck just put a sack over their butts and catch the poop too, that will generate more as it decomposes!
Let’s all get rich
There’s some info about how much cows produce here. Apparently cow belches produce more methane than farts.
There is a relatively new process where farmers can collect manure and store it to tap the methane it releases. some info here, and a video
Methane from landfills can also be tapped. BMW has a factory that runs on it.
That doesn’t answer the question, but there is a lot of methane we could use without having to figure out a way to capture farts or belches.
Hmm okay so instead of balloons, we trap the cattle on a metal grated floor so all the manure can be harvested, and the whole building is air-tight with some kind of fart/belch methane extraction system.
Sort of like Mad Max Beyond the Thunderdome.
Hmm maybe that’s cruel.
But still would like to know how much cow farts are worth.
What’s one cow fart worth? How many times do they fart per day? Same for the burps.
I don’t know the volume of a cow burp or fart but they produce a good amount of methane in a day. That first link says no one knows for sure exactly how much methane they produce but “Some experts say 100 liters to 200 liters a day (or about 26 gallons to about 53 gallons), while others say it’s up to 500 liters (about 132 gallons) a day.”
Natural gas seems to be around $2 per gallon. So, between $52 and $264 from a cow per day? Wow. There’s a billion cows in the world, using 132 gallons times a billion, that’s $91 trillion per year.
I apologize if that last post was insulting, it wasn’t directed toward you.
All right then, let’s do it. We’re the next Microsoft!
Woot
MicroStool?
Termite flatulence is worse. Facts on Farts.
Good analysis, but a tad wrong!! You have to be careful with volumes when you deal with gases.
So lets assume a round about number of 100 gallons of pure methane (it probably wont be pure but lets assume for simplification) per cow per day. Lets assume that this methane is at Standard conditions ( 32 °F and 14.504 psia). That gives you about 13.4 SCFD (standard cubic foot per day) or 13.4 x 10^-3 Thousand SCFD (also written as kSCFD where k stands for kilo)
Natural gas (pipeline quality) sells for about $4 per kSCF - so potentially, you will have a revenue of around 5c/day per cow ( 13.4x10^-3 x 4 ~ 5). In a year, the cow will give you a revenue of ~$18.
Now the recovery system that will be needed to recover the methane from cows will be very expensive - and you will probably use more energy in blowers, filtration, etc. and it will probably be a huge money loser :). Moreover - it maynot be safe to let the natural gas concentrate around the cows because you will risk explosions.
Sorry for breaking your bubble
Obviously, this thread is going more in the direction of exploiting comedic potential rather than commercial potential, but where did you get the $2/gallon figure? Even before investigating, that just sounds grossly wrong.
The commodity market for natural gas is quoted per million BTU, and is currently under $4/MMBTU. Converting to volume obviously brings up questions of energy yield and so on, but we can ROUGHLY consider a million BTU to be 1000 cubic feet, presumably at STP, which I’m also presuming applies to the “cow yield” figures noted:
http://www.tulsagastech.com/measure.html
1000 cubic feet = about 7500 gallons. So I get $0.00053/gallon as a raw commodity. That gives us a production of more like a nickel a day per cow, being fairly optimistic about the cow’s output.
ETA:
am77494’s post crossed mine. Glad to see we independently arrived at a nickel a day.
A good portion (I can’t say for sure off the top of my head that it’s definitely ‘most’, but might be) of cattle manure is collected, often more or less exactly this way.
Not because the manure is valuable, but because the cattle are being grain-fed in sheds or pens, rather than roaming pastures, and the cattle-feeders just need to get it out of the way.
Ah, I had searched for “natural gas gallon price” because I didn’t want to deal with cubic feet and ended up with compressed natural gas
A horrible “moola” pun is almost irresistable here, but discretion and good taste prevail.
I think you have to value them much like other pressings, coins for example. What kind of shape are they in… uncirculated? Minty condition?
Bad assumption. Most biogas is less than half methane. Most of the rest is carbon dioxide. Then there’s a significant amount of water vapor that has to be removed before it can be made burnable. Also hydrogen, sulfur compounds, and a few other things.
The sulfur compounds don’t have to be removed if you’re just burning it and don’t mind the smell. But if you want to run an engine or generator with it, it has to be removed or it will corrode the metal it comes into contact with.
So you’re down to 2 cents per cow per day and more processing needed. The water vapor is usually removed with a mesh-filled cooling loop and I’ve heard of the sulfer compounds being removed by running it through a filter full of iron filings. And someone has to keep monitoring both and emptying the loop and replacing the filter when needed.
All things considered, anaerobically digesting the manure is the way to go. Digesters loooooove cow manure.
(Oh, the CO2 doesn’t have to be removed in order to use the biogas, it just doesn’t produce any energy so it decreases the value of any eructations in question.)