Someone in another forum made a comment about farts and how you could light one with a match & it would burn. This got me thinking so I looked into it and found some interesting things.
Chemical Composition of Farts
The exact chemical composition of human flatulence varies from one person to another, based on his or her biochemistry, thebacteriainhabiting the colon, and the foods that were eaten. If the gas results from ingesting air, the chemical composition will approximate that ofair. If the fart arises from digestion or bacterial production, the chemistry may be more exotic. Farts consist primarily of nitrogen, the principal gas in air, along with a significant amount ofcarbon dioxide. A typical breakdown of thechemical compositionof farts is:
Nitrogen: 20-90%
Hydrogen: 0-50% (flammable)
Carbon dioxide: 10-30%
Oxygen: 0-10%
Methane: 0-10% (flammable)
Human flatus may containhydrogen gasand/or methane, which are flammable. If sufficient amounts of these gases are present, it’s possible tolightthe fart on fire.
EXXON Mobile is spending millions to improve the yeast output of alcohol. I wish them the best in their ind-ever but I think they would have better results using the hundreds of thousands of sewer treatment plants, converting this waste into useful energy.
I have toured sewage treatment plants as part of college level microbiology classes. One I went to harvested and stored the methane it produced, but it only got enough to heat its own buildings through the winter.
Only about 1/3 of humans ever have methane in their farts, anyone may have hydrogen gas. For most of us, therefore, the ingredient that burns if you light it is hydrogen.
Source: QI (Quite Interesting), a sort of panel quiz show on BBC2.
As I understand it, that’s not an uncommon arrangement on livestock farms, too. The manure goes into a digester, where the methane produced can be collected. But like you said, this generally only produces enough gas to heat the farm’s own buildings.
A different arrangement I once heard a scientist advocate on NPR’s Science Friday years ago is to use sewage treatment plants as algae farms. The algae would help break down the sewage and remove CO2 from the atmosphere. The algae could then be harvested to produce biofuels, creating a carbon-neutral fuel source.
Mythbusters did a whole episode on farts. In it, they set up a contraption to capture a fart in a bathtub so they could analyze its contents.
I don’t recall the results, but good luck getting this image out of your head.
That kind of technology is being tested out as well. That EXXON is investing in other research shows that sewage gas hasn’t so far proven itself to be a perfect solution that will solve all energy demands all by itself.
I totally agree; adding that it will not be just one new energy source, we will need to use them all if we are to save our hides before the sun bakes our ass’s dry
“a possible new source of energy, flammable farts”
Before you stuck your but into this discussion a few posters were trying to honestly discuss the energy potential of converting sewage treatment plants into self-sustaining facilities. The plants would get their power from the sewage they treat. I believe this could qualify as the first perpetual motion machine in our history.
I recall an NREL report estimating the potential for about an eighth of a quad’s worth of methane from domestic municipal wastewater, annually. Not much, but every bit counts. It’s a relatively low-hanging fruit. DC’s Blue Plains treatment plant has a digester hooked to a 13 MW CHP turbine. This just offsets some of the plant’s power needs; the plant is still a net consumer of energy. But I’ve been told their output stream is cleaner than the Potomac water they’re dumping it into. Other plants may have less stringent requirements, but I’m not up to speed on this.
1 quad = 1 quadrillion BTUs ~ 1 exajoule
We use about 100 quads/year from all sources.
