Anaerobic Digesters

Started by tjm73, August 21, 2006, 03:06:28 PM

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tjm73

I'm trying to learn more about anaerobic digesters and their use to make methane gas, but internet searches are not turning up much.

Given the often suprising range of knowlegable folk here. I thought maybe someone might have a link or book or something they can point me towards.

Also if anyone has any info on modifications a regular old gasoline engine needs to run properly on methane gas, please post that too.  :)  From what I can tell it needs pretty much the same mods as a propane powered conversion. But any info on that is scarce at best it seems.




Miedrn

Another PDF talking about requirements and safety:

http://www.ext.colostate.edu/pubs/farmmgt/05002.pdf#search=%22methane%20gas%20to%20gasoline%22


It's enough to get someone started in researching the subject anyway although I don't know anything about it personally.

Amanda_931

#4
The Build-it-Solar seems to have a really nice page on biofuels in general--including, as suspected the links to the Rebel Wolf articles..

(And I think the pictures were of vehicles running on wood-gas--also in the build-it solar)

The Man in the U.S. was the late Al Rutan.  A lot of workshops and some writing.  You could run a search, but here are a couple.

http://www.builditsolar.com/Projects/BioFuel/biofuels.htm  This probably sends you to the Rebel Wolf article(s}.

.pdf from home power:

http://homepower.com/files/methane.pdf#search=%22Al%20Rutan%20Methane%22

And we've had a thread here involving Jean Pain, I think. Yep, that's him.  And an old Mother's article to start you out there.

http://www.motherearthnews.com/Organic_Gardening/1980_March_April/The_Genius_of_Jean_Pain

And I think that Glenn posted some pictures posted of a car (pre WWII) running on methane from a digester.  I've seen some somewhere.



Amanda_931

I had read some things by Rutan, but not the Homepower series, all collected in the .pdf above.

Start there.

It's wonderful.

He goes through what size tank you need to produce all the methane you need for the homestead, what's the most humane way to collect your manure, advises you to be aware that the critters in your tank are alive and need to be babied--he talks about somebody kicking his tank--it stopped producing for a while.

Jean Pain is using wood waste.  A completely different idea.  Maybe better for those of us who don't raise chickens.

glenn kangiser

I gave Gary at build it solar the links I had plus he has lots more - Amanda posted the link above.  Gary is a member here also - a real nice helpful guy. :)
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

Amanda_931

#7
When miedrn posted the link to Journey to Forever, I knew I'd seen it somewhere.

Of course, they're the people who post selections from a whole lot of old, but still useful books.   ::)

The Jean Pain article from Reader's Digest, of all places, came out roughly the same time as the one in Mother, for instance.

A really skilled tinkerer might be able to reproduce that system from the article.

Or Journey to Forever also has the link to Pain's website.  If your French is any good you can buy his book(let--I understand) from there.  At one stage they say it was available in English as well.

http://journeytoforever.org/biofuel_library.html

Glad Gary has copied your links on the subject, Glenn.

Have you done anything with methane digesters?

glenn kangiser

#8
Studied enough to know how to make and work one but haven't built one.

My own doesn't count -- does it?   :-/

Excellent heat source -- hard to maintain a constant flow --- caution----look out for burning cotton and never never ever use polyester - it melts. :-/
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.


JCL

In the 70s and 80s hundreds of biodigestors were built in Brazil, mostly from an Indian design, that was expensive and had parts that rusted easily. It seems that less than 5% of them are still in use.

It is hard work to feed constantly a biodigestor to obtain biogas in a steady flow, it can be smelly, require large amounts of manure and the digestion process speed changes with the temperature.

The actual success cases in Brazil use modified Chinese designs, developed by Brazilian universities and the navy.

They usually build clusters of small batch biodigestors as you can see on the link below, and put emphasis on the fertilizer production.

http://www.aondevamos.eng.br/boletins/edicao13.htm

Or build pairs of PVC tubes biodigestors to produce low pressure biogas. Those look too fragile.

http://www.gaia-movement.org/files/Manual%203p%20%20Biodigestor.PDF

There are also some improved large models, built with fiberglass, but I have no info about their performance.

http://www.fibraeng.com.br/pdcupulabio.jpg.

JCL

glenn kangiser

#10
Thanks, JCL -- great to see you back here.  

I read enough Spanish to get the idea on the plastic tubes.  I would worry about the plastic degrading in UV and releasing all of the gas to atmosphere at once if it cracks.  I see they shaded it to help.  I have read that tractor innertubes would work - and be more durable.
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.