biodigesters

I have heard and learned small amounts about biodigesters and what they do. I understand many less developed countries use them and that you can power refrigeration and cook using the methane gas produced from your own shit. I'm really interested and want to learn more about how they work and how to safely build one. Does anyone know of some good source for me to look up? websites, books, etc.
thanks

Also i have read that biodigesters work according to temperature. I live in upstate New York where we get cold and freezing temperatures every season. Anyone have ideas on how to work with this issue?

Here is a good video overview of a system.

http://youtu.be/W2SMQGUuY3g

I hope to have one of these systems in the future.

I think that with this system you have to be sure to spread the waste water evenly on your plants and not let any seepage happen,(to protect ground water).

These guys will sell systems to N A  when I emailed them about them they told me they had a system in Montana somewhere.  They CAN supply everything but the shipping  costs would be prohibitive.. The costs for me would have been $75 for most of the plumbing/fittings and a one burner stove. I would have to provide two water tanks and a length of rubber hose to take the gas from the digester to the stove. The cost of shipping just that stuff to central Canada would have been $375 US ( it IS  half way around the world after all) so. They do have a dvd about how to set a system up but they didn't tell me now much that would be.
http://www.samuchit.com/index.php?option=com_content&view=article&id=8&Itemid=10

The Director was very courteous and helpful and very quick to reply to my emails.

secondhandstardust wrote:
Also i have read that biodigesters work according to temperature. I live in upstate New York where we get cold and freezing temperatures every season. Anyone have ideas on how to work with this issue?

For temperate climates it seems to me like you'd want the digestion chamber to be located indoors (basement or heated outbuilding, perhaps?). I've always thought it would be cool for multi-family housing units in the city to have biodigesters in the basement that process the human waste. Some of the new Living Building Challenge projects are addressing this with composting toilets, but I haven't seen any biodigesters yet.

The first place I learned about biodigesters was EARTH University in Costa Rica. Here is a short video on the basics -> http://www.youtube.com/watch?v=pMR4KnGktds

For more information on biodigesters in the frozen north you might also make contact with the folks at Growing Power in Milwaukee, WI. I visited their urban farm a few years ago and they were installing a biodigester to process the animal manures & green waste generated on their site. They were hoping to generate enough methane to heat one of their greenhouses through the winter. http://GrowingPower.org

Dave

The people in India said that the system in Montana was put into the greenhouse and was being heated by hot water from a solar system.

Hello. I am new and have discovered this forum through Paul Wheaton's Youtube videos. I hope that I am not too late in posting this to this thread and that this somewhat messy/TL-DR compilation of resources will still be useful to the OP and others. I apologize for its wordiness (and my wordiness in general)... to be honest, it is an old list of digester-related materials that I compiled and sent to an interested uncle (and an individual on YT who saw a comment of mine on a biodigester video).

The list below was some of the best videos I had encountered at the time of making the list. There are probably better and newer videos out there that I have not seen yet. If you know of any, please let me know (thanks to the posters in this thread, I have added a couple of new ones... fanfare.wav). Most (if not all) of the videos come from the following YT playlist that I (often neglectfully) maintain: http://www.youtube.com/playlist?list=PLDF708513B8974349

I cannot vouch for the validity of any of the claims of systems seen in the various videos, I am merely fascinated by the topic. Some of the set ups are very likely to have aspects of their design or implementation that are less than ideal. For instance, when it comes to Western sanitation standards and a certain "ick" factor, I can imagine some ppl might not be so comfortable with some of the footage or designs found below. Likewise, several of the industrial-scale applications of this technology are a far cry from anything seen in something like "One Straw Revolution"/etc. Finally, as with anything (but especially with something like this which requires the containment of gas and use of that gas), SAFETY SHOULD BE YOUR FIRST PRIORITY. While I think this technology and what it offers is promising and I hope many people will begin experimenting with different types of systems, I do not think it is appropriate for casual DIY'ers (like myself) to take on something like this alone. It most likely requires the help of people who understand the proper installation of lines that are not leaking and so on (in my case, this person is a trusted uncle). Therefore, I urge everybody who undertakes even a small biodigester project to have others of exceptional skill and knowledge help you do the work, as well as check that work over repeatedly, test it thoroughly, and monitor and maintain the digester regularly once you are using it as designed. Reports of explosions and horrible accidents at both small and large digesters are out there (e.g., http://www.hindu.com/2009/08/27/stories/2009082761930100.htm ). It is advisable to take as many precautions as possible if designing, building and using a biodigester. Regardless of these very serious concerns, I do think there is a place for research and tinkering in this area by willing and (most importantly) able individuals out there in cyberland.

In conclusion, thanks to all of you for everything you post on this forum (and the net... and for all those great YT videos that led me here, and all the awesome ppl out there that are looking for new ways to do things, etc.). The more information and experimentation we have going on, the better (as far as I'm concerned)... Hope everybody had a great Turkey Day, if you are so inclined to celebrate it.

~Cantecleer

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General Videos

1. Biogas as an alternate to wood burning (which is both time consuming, contributes to erosion/ground water problems, and respiratory problems). The system discussed in this video is a "fixed dome" type... it contains a nice animation around the 2:30 time mark. It also contains a bit of discussion of how ambient air temperature and digester exposure to thermal heat from the sun are important to maintaining an environment where the anaerobic bacteria can thrive: http://www.youtube.com/watch?v=GQrr4KhP4Dc

2. "A high-tech space research organisation in Ahmedabad, Gujarat, uses its canteen waste to generate biogas. Thus taking care of the institute's waste disposal problem, and also partially substituting LPG with biogas for cooking in the canteen." http://www.youtube.com/watch?v=nqL8D3znqyE


A. ARTI/Floating Drum Digester

1. This one is for food scraps only... it won some "sustainable technology" award. Obviously, I'm not sure about the engineer's claim that it is 400 times as efficient as a traditional dung-based digester, but overall, it seems pretty on the up and up:
http://www.youtube.com/watch?v=BGSl72xZHNk

2. Here is a video by an guy that has an ARTI/floating canister set up in his backyard... I think he is affiliated with some stateside university... http://www.youtube.com/watch?v=bG5sjnwldjs

Here are a couple of videos where they did a timed burn test:
http://www.youtube.com/watch?v=HnYoRxDMvqo
http://www.youtube.com/watch?v=FankG3g0Ebo ***he takes awhile to get back to the biogas burn test. He shows an interesting gray water set up, though.

Here is a video of the German guy's kid explaining the biogas setup. It's in German, but is pretty self-explanatory if you've watched the previous videos. It is kinda funny when the exit tube for the effluent comes apart: http://www.youtube.com/watch?v=wvJ498BvIBo

TCULHANE's youtube "channel" is definitely worth looking at... lots of interesting projects. He's the guy who has videos of running a generator off of biogas (though he admits limitations to his mechanical knowledge with regard to the two stroke engine): http://www.youtube.com/watch?v=VCD6p1zxmLs

Anyway, one of many awesome channels on youtube.


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The following three videos aren't really ARTI/floating canisters, but they don't fit elsewhere and there are some superficial similarities to ARTI digesters, so I am just including them here....
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3. This one shows some ways to convert a single drum into a digester. The video is interesting because the guy shows a crude drawing of using other tanks to help remove CO2 and Sulfur from the gas. This is much better than A.5 imo, but it takes some of the designs from A.5: http://www.youtube.com/watch?v=l5e_2W71jMM

4. A video of some University of Florida's student's study on the feasibility of using food waste from a campus dining hall. Not a lot of hard numbers or build info, but interesting to think of how universities and large public institutions which generate a huge amount of food waste could offset a lot of their cooking/heating costs if they just used biogas generated from that waste: http://www.youtube.com/watch?v=r8HDb1at6dI

Oh, and here is a related video of UF students who apparently took over after the original guy graduated (and tried to make improvements on the design and continue the original guy's first steps): http://www.youtube.com/watch?v=NZFrPZZIFTs

5. Three videos of somebody's DIY single-barrel digester build. There are some good and bad things about these videos, tbh. For one, I don't think a setup like this would produce gas as well as one of the "floating canister" as seen in A.1 or A.2. Also, the foam he sprays on the inside of his barrel would probably leach some nasty VOC's into the effluent (and I would think twice about putting it on a garden or crops meant for consumption). Plus, he complains about the smelly effluent, but that is because he is using meat scraps... From what I have seen of the other digesters, meat is not really preferable and smell shouldn't be an issue if the anaerobic process is working properly. Finally, the way he used a drain pipe to disperse his effluent is problematic. Commenters rightfully point out that whatever he plants will eventually grow into the pipe, clogging it at some point. Anyway, here:
http://www.youtube.com/watch?v=SrVC4XKR2s4
http://www.youtube.com/watch?v=y-RyysPU1Hw
http://www.youtube.com/watch?v=1MP5wI132u4


B. "Polyethylene Lining in a Covered Ditch" Digester <--- one of my favorite types, if only it weren't for the use of plastic

1. This one is in Spanish: http://www.youtube.com/watch?v=hjoSNv_plZQ
But, if you look through the companion website found here: http://www.ruralcostarica.com/biogas.html ... you will find a translation of what they are saying in the video ( http://www.ruralcostarica.com/biogas-video.html ). The website also has a section about how to build one with some pictures. To be honest, you can just watch the other videos in this section and look at the ruralcostarica's build instructions (in English) and then the spanish only video makes sense...

2. A commercial grade operation in New Zealand. Nice visuals and explanation of the general set up. There is some attention paid to a "water filter" which some other digesters feature. It is essentially a water tank that the gas passes through prior to use... The H2O removes some of the CO2 from the gas, yielding a higher methane concentration at the point of use (you can see a crude drawing of the same thing for one of the DIY ARTI's above... that drawing includes a Sulfur scrubber, but makes no explanation of it.... it is A.3, I think): http://www.youtube.com/watch?v=JCJyyA8LlnY

3. Another very impressive, detailed video showing several steps of building a larger set up. There are dimensions provided for a much more modest sized unit though (3m length):
http://www.youtube.com/watch?v=8J3IoLLGmW4
http://www.youtube.com/watch?v=D_qqpHJSghQ

4. A very good video (poor image quality tho) that shows a build in Bolivia. I question the appropriateness of this type of digester there, where the temperature tends to be low. It seems the polyethelyne lining type digesters are better for warmer climates, imo. They do enclose it and use plastic to create a greenhouse effect, but from what little I know of Bolivia, I think the cold weather might inhibit methane production. Still, a good video (with interesting music): http://www.youtube.com/watch?v=3Sl0XEN5Bgo


C. Fixed Dome Digester

1. A very nice series of videos showing how to build a fixed dome design. This is a Vietnamese build. Apparently, the fixed dome design is very popular in several SE Asian countries (including the Phillipines... at least relative to the floating drum design/ARTI which is more common in India):
http://www.youtube.com/watch?v=ne3RdAmPIbw
http://www.youtube.com/watch?v=WJDl4jUsi7M
http://www.youtube.com/watch?v=6P5Fn7WsW2E

2. Another good video (from the same person) of another Vietnamese fixed dome build. This video is great because it pays extensive attention to choosing materials for this type of system. Unfortunately, the last three videos have not been translated yet, but they probably will be at some point:
http://www.youtube.com/watch?v=IpStsylTkKY
http://www.youtube.com/watch?v=4pmqIBOuU-o
http://www.youtube.com/watch?v=D1oUm8aKKcs
http://www.youtube.com/watch?v=nFiKCaIFd0g
http://www.youtube.com/watch?v=BUepndxHe54

3. This is from a series of videos about an organic farm in India. It's good because it shows the general operation of a fixed dome (nothing technical though).... But, it makes a point about the benefit of getting gas and quality organic manure from animal waste and that manure processed in a biodigester that is not dried when applied to plants = higher nitrogen content for plants.
http://www.youtube.com/watch?v=KM9SZyPpm-I


*** Of course, as with anything like this, there are MANY other videos and excellent sources of information. For example, this word document describes a "Four in One" build type that is common in China (and possibly the Phillipines): http://www.snisd.org.cn/enhtm/four-in-one%20biogas%20technology.doc ... For every video I link, there are probably 10 more that are equally good and illuminating. What I've sent is just to give a general overview of some of what is out there. Plus, the same applies to websites. The ruralcostarica one and the "four-in-one" plans that come from a website are just a sample of the resources and information available (with some digging).

P.S. Here is a PDF of the 4-in-1 design if, like me, you are having trouble getting the .doc link to work: http://www.ecosanres.org/pdf_files/4-in-1_Household_Biogas_Project_Evaluation-20110620.pdf

Of potential interest to the OP's and the matter of cold weather digesters:

"The greenhouse permits continued agricultural production even during cold winter. Survey results indicate that the average temperature in the greenhouse is about 16oC in winter, compared to -15oC ~-25oC ambient temperature...."

I think a 4-in-1/greenhouse type enclosure that surrounds the digester might hold some promise in providing the necessary warmth needed in colder months (not sure if it could overcome prolonged cold weather)... It would help if it were built to where the sun-exposed walls of the digester were fronted by 55 gallon drums full of water to provide thermal mass and radiate heat back into the space/digester during the colder night (a bit like what is seen in this video: http://www.youtube.com/watch?v=gshyZ0qJx2c ). Furthermore, something like a Walipini Underground Greenhouse might point the way toward a solution: http://www.bensoninstitute.org/Publication/Manuals/Walipini.pdf , http://peswiki.com/index.php/Directory:Walipini_Underground_Greenhouses , and even a forum topic from here: https://permies.com/t/2505/green-building/Walipini

Or, perhaps digesters could be built inside of a greenhouse type enclosure (or even as a standalone structure that stores passive solar heat gain in thermal mass), using principles found in Earthships/earth-bermed structures.

For instance, "Polyethelyne lining in a ditch style" digesters could possibly work well in colder climates if built like the classic "U"-shaped earthship (i.e., a south-facing greenhouse wall emitting light that warms thermal mass of some kind, which in turn is then backed by a thermal wrap/insulation layer and ultimately buried under an earthen berm or even carved into hillsides/etc.). An important point would be to make sure to keep the actual digester plastic out of ANY sunglight (the digester walls itself and/or nearby drums of water would absorb the heat and radiated it into the actual digester chamber). Think this: http://www.builditsolar.com/Projects/SolarHomes/Earthship/PkgEarthship01.png , the "rooms" of the house being the digester chamber (where the polyethelyne lining sits) and the only difference being that light hits a wall of thermal mass as soon as it enters the structure (and that wall, of course, is what protects the lining from UV damage).

I imagine there are other approaches that could work, but hopefully some of these suggestions prove fruitful.