Human waste as fuel

Una,

I read your recent column on human/animal waste as a possible fuel source. The column was focused on large-scale energy production.

This is smaller scale, but I remembered reading this:

Wired News - Jul 16, 2005
Human Feces Powers Rwandan Prison
http://www.wired.com/news/planet/0,2782,68127,00.html

Seems the article skipped over a few points - one of them being Anaerobic digestion at wastewater treatment plants. The largest that I am aware of is Deer Island in Boston Harbor, which reportedly produces about half of all the power at the plant and heat for all but two months.

The dried sludge is then processed into pellets which are used as fertilizer.

http://web.mit.edu/seagrant/edu/res/bostonsewage/treatment/sludge.html

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There is also Thermal Depolymerization Processing, which may efficiently (or may not - I remain skeptical) turn waste products such as plastics, offal, and sludge into petroleum and gas products.

http://www.sovereignty.org.uk/features/eco/zwaste2.html

http://en.wikipedia.org/wiki/Thermal_depolymerisation

Welcome, foobar11235!

Normally, around this time, some comes along and welcomes you (check), then mentions that it is considered good form to reference the article with a link. You can easily make such a link by simply copy-and-pasting the url into your text, with a space on either end. Like this: http://www.straightdope.com/mailbag/mmanurefuel.html

That being said, excellent report, Una. I had no idea you were hip-deep in the subject, so to speak.

The city of Tampa has been burning poopy forever. If you live in tampa, the lights in your bathroom are powered by what goes in the toilet. Here is a link to the whole operation:
http://www.tampagov.net/dept_Solid_Waste/environmental_coordination_division/mcKay_bay/McKay_Bay_Refuse_to_Energy_facility.asp

Can you check your link? You link goes to a waste to energy site, which is not the same thing as what my article was about. Perhaps you had another window open? Because I see no reference at all to sewage sludge being burned on that page.

My article length and scope is tightly controlled by Ed to make it approachable to a wider audience.

Good link; I’ve heard of similar systems employed on very small (household) scales in China as test cases, but I’d never heard of this prison in Rwanda. Thank you.

If you can burn it, I’ve likely had to do a study on it…thanks!

Just don’t ask her about the time she was commissioned for the study on an asbestos-fired power plant…

[obligatory flirting]
Allways knew you’re hawt! :wink:

So how you doin? :cool:
[/o f]

Great report, Una.

It looks like San Franscisco is thinking along your lines: S.F. Examines Power of Dog Droppings.

for much of Tibet, the only fuel source is dried yak dung. It’s pretty odorless actually and works pretty well given the environment

Seems Una has tipped some enterprising soul(s) into a hog heaven of a goldmine! (To mix metaphors with atrocious aplomb)

Hog farms must deal with the waste eventually one way or another. Seems There ought to be a way to collect swine manure with little or no human intervention (Envisioning some Rube Goldberg contraption consisting of graduated screens, sweepers and scrapers)

Once collected, and allowed to dry or otherwise chemically altered to allow more testing up close and personal it could be the makings of a Nobel Prize for the SDSAB (Not to mention lots of well-heeled Straight Dope shareholders) :wink:

It’s like another question I’ve been asked a lot about lately: why can’t we just use machines to mine coal, instead of humans?

It’s a complicated process, and still labour-intensive, to gather biomass in an entirely automated manner. Improvements are made steadily, but even under the best circumstances giant hog facilities smell horrible.

Thanks for another great article, Una. I hereby authorize you to add an oak leaf cluster to your Hero of the Straight Dope medal.

Thanks! I can wear it next to my SDMB Purple Heart.

Fair enough. However, I would again state that there are many large scale hog farms in the US and around the world, and haven’t heard of any ever-growing mountains in Iowa beneath them, so the waste is cleared away regularly by some form of human intervention.

Whether it be as simple as cotton balls and a clothespin, or requiring environmental suits with SCBA, there has to be a viable way to overcome the olfactory issues involved with the collection/extraction of hog waste.

With that hurdle overcome, then it’s simply a matter of whether a fuel can be efficently produced for internal combustion engines and/or electrical generation.

I can see the slogan now, “Don’t be an energy hog, use Hog Energy!” :slight_smile:

Today’s New York Times has an Op Ed piece that takes a dim view of manure to energy plans. The author, a lawyer and cattle rancher, notes that small scale operations tend to use manure as fertilizer, which is probably a better use of the stuff.

Manure-power subsidies tend to encourage larger scale factory farms, whose volume of animal waste requires some extra management. These larger scale farms are not especially eco-friendly according to the author.

A Load of Manure (reg req, unavailable in 2 weeks).