Small scale biogas digesters built with local material by local people.

[Travis Linds]

I'd like to include discussions regarding biogas generation in this group, if no one objects.

Brian from Inspiration Farms and I have discussed and plan on building a small scale biogas digester this spring and start planning for a larger unit that can handle the waste generated from his farm and collect the gas for cooking, lighting, heating and possibly powering a generator is sufficient volume is produced (possibly only during summer months). Ideal use of this biogas is to have it fuel a fuel cell and produce electricity much more efficiently and quietly than a generator.

Here is the pdf of the manual that we are going to use to help us with our full scale digester.
http://www.fastonline.org/CD3WD_40/JF/432/24-572.pdf

Here is a good video Brian found:

Anyone want to volunteer and help with this project?

[Heather K]

Yes! I'll help! And I'll pass the word when we need to gather more volunteers together.
Put me on your email list/phone list for dates & times. (I'll be away in February & early March).

I look forward to us celebrating together with our first cup of cow-poo brewed tea! :-)

I'm hoping there will also be interest in a stationary bicycle design for running a smoothie blender.

[Heather K]

“The production of biogas, which is regarded in many countries as a by-product of an efficient system of energy production, has become in China a comprehensive, controlled method of waste disposal, recycling resources, supplying energy & fertilizer, and improving rural health, as the digesting of wastes in a closed container kills many of the pathogens responsible for common human diseases.”
- quote from - A Chinese Biogas Manual (ISBN 0 903031 65)

A couple questions I thouht of: Is there any info you've seen on capturing human wastes to be included with the animal waste in producing the methane gas?.
I'm thinking of some combo of an enclosed bacteria-composting-potty connected to an 'enclosed septic tank-bio-gas generator', that both captures the gas from decomposition, and captures & stabilized the nutrients in a form they can later safely be utilized for maintaining soil fertility & tilth?

Do you know the ideal time range in our cool northern climate for allowing the anaerobic animal resources to stay in the enclosed container before coming out onto the earth?
And, is there a secondary aerobic composting process for these materials before they are added back to the soil's fertility cycle?

I'm wondering what type of 'fuel cell' you're considering using.

The links you posted are great! I'm trying to recall if we have a place on our Transition whatcom site to file good links like this into an 'online library' of sorts.

[Travis Linds]

The fuel cell would be something that could possibly come at a later date. Using fuel cells with biogas is still at a preliminary stage. The most common to date are solid oxide fuel cells (ceramic), which can handle the biogas stream without posioning the membrane. http://www.treehugger.com/files/2007/06/biogas-powered_fuel_system.php

The plan for the final digester would be to have it below ground, and well below the frost level, this allows for yearly production of biogas, although it would be slower in winter. If we we able to supply enough gas for running a generator, the heat waste can be captured (via heat exchanger) and routed to the digester to keep it warm and keep production up especially in the winter.

Once the digester is in operation and we prove that the temperatures are high enough to break down any pathogens found in human waste, I would think that it could be included. No doubt, these digesters in rural China and India include human waste.

[David Culver]

I am so glad you have started this thread. I would also like to help. Count me IN!
I'll be in touch. Thanks Travis

[Travis Linds]

I found a document on how to make a simple drum small scale digester. I have access to drums required and propose we follow this same method for the first, small scale test unit(s).

http://www.fastonline.org/CD3WD_40/CD3WD/APPRTECH/FB32BE/EN/B97_1.HTM
Some additional information is found in this earlier document.
http://www.fastonline.org/CD3WD_40/CD3WD/APPRTECH/FB31BE/EN/B96.HTM

I also really like this Biogas Handbook that uses a larger cylindrical steel tank as the digester inside of a greenhouse, something like a large fuel storage tank. We could probably find something suitable at Zees.
http://www.fastonline.org/CD3WD_40/JF/432/24-571.pdf

This website (http://www.fastonline.org/CD3WD_40/CD3WD/INDEX.HTM) has a huge wealth of infomation on biogas. Here are some that are useful for reference.

http://www.fastonline.org/CD3WD_40/CD3WD/APPRTECH/G32BIE/EN/B142.HTM
http://www.fastonline.org/CD3WD_40/CD3WD/APPRTECH/G33IME/EN/B975.HTM
http://www.fastonline.org/CD3WD_40/CD3WD/APPRTECH/G34BIE/EN/B112.HTM
http://www.fastonline.org/CD3WD_40/CD3WD/APPRTECH/G36ENE/EN/B512.HTM
http://www.fastonline.org/CD3WD_40/JF/432/24-569.pdf

[Travis Linds]

Tom Anderson directed me towards dry anerobic fermenting as an alterntive to the wet, slurry method. It certainly appears to have benefits over the slurry method. His suggestion is as follows. "My thoughts about how to do this on a small scale are to start with 4 reactor 55 gal drums, one liquid drum and one gas storage drum. That way you could set it up to fill one reactor drum per week and have a 4 week digestion period."

I am leaning towards dry, what do some of you think?

http://www.seagrant.wisc.edu/WaterQuality/portals/9/Williams%20Pres...
http://orgprints.org/6590/01/MET77.pdf
http://www.bekon-energy.de/english/BEKON-Processdescription.pdf

[Ed Lofquist]

Reality comes in 2 forms. There is the scientific facts and then there is the ignorant public's interpretation of the facts. The latter is the major reality.
Organic fruits and vegetables are an important commodity to many in Whatcom county. No matter what your good intentions might be connecting this commodity with human waste in any way will have profound negative impact. Can this human waste inclusion before it bites us all in the butt!
Ed Lofquist

Heather K said:

“The production of biogas, which is regarded in many countries as a by-product of an efficient system of energy production, has become in China a comprehensive, controlled method of waste disposal, recycling resources, supplying energy & fertilizer, and improving rural health, as the digesting of wastes in a closed container kills many of the pathogens responsible for common human diseases.”
- quote from - A Chinese Biogas Manual (ISBN 0 903031 65)

A couple questions I thouht of: Is there any info you've seen on capturing human wastes to be included with the animal waste in producing the methane gas?.
I'm thinking of some combo of an enclosed bacteria-composting-potty connected to an 'enclosed septic tank-bio-gas generator', that both captures the gas from decomposition, and captures & stabilized the nutrients in a form they can later safely be utilized for maintaining soil fertility & tilth?

Do you know the ideal time range in our cool northern climate for allowing the anaerobic animal resources to stay in the enclosed container before coming out onto the earth?
And, is there a secondary aerobic composting process for these materials before they are added back to the soil's fertility cycle?

I'm wondering what type of 'fuel cell' you're considering using.

The links you posted are great! I'm trying to recall if we have a place on our Transition whatcom site to file good links like this into an 'online library' of sorts.

[Tom Fisher]

Hi all,

I just joined and noticed this discussion. I personally am interested, and would like to meet with you about it, and help with it to. Also, would like to make video of it for my website.

I've been looking at an ebook on 'Build A Biodigester To Produce Biogas At Home', that teaches how to do this. Let me know if you have heard anything about it. I am about to get it myself.

I think biogas/methane is a very good way to go, but the commercial ones are way to expensive.

Looking forward to meeting.

Tom

[Travis Linds]

Here are some great links for biogas.

LINKS

[Tom Fisher]

Link didn't work. Just type the url. Okay.

Thanks,
Tom

Travis Linds said:

Here are some great links for biogas.

LINKS

[Travis Linds]

Whoops, try this:

www.green-trust.org/Al%20Rutan/

[Travis Linds]

TOM, did you get the e-book? How is it? Can you e-mail me a copy to [e-mail]

Tom Fisher said:

Hi all,

I just joined and noticed this discussion. I personally am interested, and would like to meet with you about it, and help with it to. Also, would like to make video of it for my website.

I've been looking at an ebook on 'Build A Biodigester To Produce Biogas At Home', that teaches how to do this. Let me know if you have heard anything about it. I am about to get it myself.

I think biogas/methane is a very good way to go, but the commercial ones are way to expensive.

Looking forward to meeting.

Tom