Methane Biogas book recomendation

Hey Folks,

Still working on my methane digester idea and trying to self educate along the way. I have been watching a lot of You Tube vids and trying to glean as much as I can from online sources. While there is valuable info there I still have pieces of info missing. While a lot of the videos are very helpful, the ones I have found have assumed you already know all about biogas. The basic concept and digester mechanics I understand. I am having trouble finding good info on scrubbing the methane once it leaves the digester. I see some folks using water, some using steel wool, some using lye water, etc. but I don't exactly get what is going on in these scrubbers and why.

Can you kind folks recommend a "methane digesters for dummies" book that will help me fill in the gaps on the scrubbing end of the process?

Thanks,

Ray

Biogas Handbook, by David House.

I won mine from this forum a while back, and it's great!

Do some searching online, though. There is a lot of info about that. Here's a good place to start: http://www.cd3wd.com/cd3wd_40/cd3wd/index.htm

Thank you Abe! That will go on this months Amazon cart.

I appreciate the link as well.

Ray

I really recommend you reading up on Jean Pain, Al Rutan, David House, and search youtube and google for biogas. There has been so many things done, tons of manuals online, tons of videos.

Personally, I like the flexible tube design, which is basically a long bag. On each end of the bag, you make a simple inlet/outlet with a 4" PVC, and the bag is cinched around the pipe. Somewhere in the middle of the bag, you can has a gas takeoff. The nice thing about that design is that you keep all seams below the water level, so you only have low-pressure water seals to worry about, instead of a gas seal. These are super cheap, super low tech, and you could make one in an hour. Here's how to make it:
http://www.berglib.com/info/bf4a51be10h32i0

Thanks Abe for the input. I can't get the vid to work. I'm on an old IMac and the files says its MSDos executable.

what vid? that was pdf document. PM me, and I'll send it to you.

Hi Ray and any other mac users having a problem with the link,
Yesterday when I tried to download, put in the code, hit download, a little action happened and then nothing. Today, put in the code and a link to the actual pdf came up. Below is a link to the file, not going through berglib, that worked for me. Using alternative text because the address is long. Digester PDF

Ray Cover wrote:Hey Folks,

Still working on my methane digester idea and trying to self educate along the way. I have been watching a lot of You Tube vids and trying to glean as much as I can from online sources. While there is valuable info there I still have pieces of info missing. While a lot of the videos are very helpful, the ones I have found have assumed you already know all about biogas. The basic concept and digester mechanics I understand. I am having trouble finding good info on scrubbing the methane once it leaves the digester. I see some folks using water, some using steel wool, some using lye water, etc. but I don't exactly get what is going on in these scrubbers and why.

Can you kind folks recommend a "methane digesters for dummies" book that will help me fill in the gaps on the scrubbing end of the process?

Thanks,

Ray

Also, take a look at Steven Harris' stuff at http://www.solar1234.com

Lots of neat energy solution books there.

Hello
I found this one and http://www.permaculture.co.uk/videos/building-simple-two-barrel-anaerobic-digester it seems a much simpler set-up than the polythene bag. I hope it is helpful for you

THanks everyone. I am leaning toward the two tank system for a couple of reasons. First I already have everything except a few PVC fittings in my shed to make that kind and secondly I live in town and I have to be careful how things look.

The lady who lives behind me has already called city hall earlier in the spring claiming I was illegally dumping yard waste down the storm drains when she saw me piling sticks in the bottom my new garden boxes. She is a nice lady but I don't think she sees very well anymore and her imagination fills in what her eyes can't make out. I'm quite certain that if I had a large black plastic bag in my backyard she would have the police there looking for the body. LOL

I understand the actual digester construction fairly well. The main thing I need to learn now is how to scrub that methane to clean it up and make it safer for home use. Right now all I am planning on doing with it is running my BBQ grill. This is a test run for a larger house project in the future so I want to learn how to clean it up more than just what I would need for my grill.

Ray

you probably won't have to scrub it much. I think you can pass it through water and construction lime to help reduce the CO2

those 2 barrel systems look nice, but they are a PITA for adding feedstocks. Also, they can leak in the space between the 2 barrels, so be careful with that.

For a continuous system, you really want a horizontal layout. Each time you add feedstock (every day or so), it overflows slightly on the other end, and the feedstock slowly moves through the system. I can't remember the formula off hand, but you want it to take about a month for the feedstock to move through.

Of course, if you are only adding feedstocks once a month, a batch design like the 2 barrel is better suited towards that, but you won't have a constant gas production rate.

Ray, I am a biogas expert and always recommend "A Chinese Biogas Manual" for an introductory text to biogas. It is quite dated, especially regarding digester construction----the Chinese over-size their digesters 10 times more than necessary in order to produce sufficient gas in the wintertime. However, it is a very good introduction to the 5 basic principles of making flammable biogas and how to keep your digester operating at peak performance. The most important thing is to have a digester properly sized for your needs to avoid overloading it. It is available for free here...

http://www.fastonline.org/CD3WD_40/JF/432/24-572.pdf

And can also be ordered from Amazon or elsewhere for less than $20 or so.

People bubble biogas through lime water or through iron oxide "iron sponge" filters to remove a highly poisonous gas called hydrogen sulfide (H2S). This will be necessary if you plan on burning biogas indoors. We import these filters for small (less than 5 cubic meter/day) digesters and offer them for $19 + shipping if you are interested. Once the H2S is removed, however, biogas has no odor at all. I recommend installing a flammable gas detector---looks like a smoke alarm available at your local hardware store---within 6' of your stove. We also offer double-burner biogas stoves with the correct fuel-air mixture for biogas for maximum efficiency. Feel welcome to contact me for a catalog.

The biogas will not need any other conditioning to burn. Keep in mind it has a high water content and will accumulate in the gas outlet hose, especially near the outlet. This will need to be periodically drained back into the digester or it will block your gas flow.

If you look at our biogas digesters on the website http://www.hestiahomebiogas.com these can be used in the densest urban environments without any problems and are extremely easy to load. Pick up the lid, pour your bucket of compost in, shove in any floating material with the loading tool. Takes 2 minutes per day.

If you or anyone else is interested I am giving another 2-day biogas workshop on June 2-3 in Eugene, Oregon. The workshop will be conducted on-site with a working biogas digester at an ecovillage of 25 people and participants will have an opportunity to have hands-on experience with biogas, see it burn and cook stuff with it. Participants are guaranteed to come away with the knowledge to produce flammable biogas anywhere day or night, rain or shine.

https://sites.google.com/site/eugenebiogasworkshop/home

The last one in April was a huge success. I learned as much from the great group of participants as they got from me!

Not sure if you have experience creating flammable biogas before, but feel welcome to ask any questions here and I'd be happy to answer them for everybody to see. It'd be helpful if you had a guess how many gallons your digester is and what you are planning on feeding it.

There are essentially "Five Necessary Conditions for Anaerobic Fermentation." The first three are controlled by digester construction they are:

airtight environment, 90% water content (including the water content of your feedstocks), heating in one of the 3 temperature ranges: cryophilic (50-80 F), mesophilic (80-95 F) and thermophilic (120-125 F).

the remaining two are controlled by loading:

proper 25:1 C:N ratio, same as aerobic compost pile, and neutral pH balance (between 6-7.5).

Stirring and cutting up feedstocks into smaller pieces for bacteria to have more surface area to attack is helpful but not always necessary.

Here's a brief video of one of our home digesters and you can see the biogas actually burning in the rudimentary burner (we offer real double burner cooktops with the proper fuel-air mixture for biogas).

Hestia Home Biogas video

Hi Wayne,
I'm in Oregon, and would like to attend your workshop, but have a scheduling conflict for the June dates. I hope you will post any future workshops here at permies.
Thanks,
Gani

I will indeed, Gani. Thanks!

THanks for the info Warren and for the pamphlet. One more question. As I am working out my plan for my backyard I am including a methane digestor to run my outdoor gas BBQ grill off of and about three gas lights on the back patio. I use my BBQ grill often but not daily. I am sure the same would be true of the gas lights.

That brings up this question. Will it harm a digester if you do not use the methane off of it regularly. Since the system will continue to produce gas even if when you are not using it, is it possible/necessary to put a pressure valve in the system to safely bleed off the extra gas?

Ray

I saw in the Philippines where the pig's pop is used to get gas for cooking..

Ray, good luck with your project and I hope you'll post pictures and links for others to follow as biogas is simply amazing. The biogas digester will need to be used regularly to avoid excessive gas build-up. Our home digesters at Hestia have an inflatable top and when gas becomes excessive will begin to push the water up out the inlet and it will spill over out the hatch. Causing quite a mess, however, if left unattended it would eventually push enough water out to where the gas "burped" out the inlet and escaped. Without some such method of pressure relief, biogas can build up to very unsafe pressures.

What we are developing and you could do with your yard lights is to have a pressure switch in them that activated the light when the gas reached a certain pressure and burn it off with one of the lights. We are developing a decorative Victorian gas lamp to do this exact same thing and give people a cool light in the backyard on warm summer evenings when gas production is high.

So you are aware high-methane (60-70%) biogas if burned efficiently is not visible in daylight. This is a problem we have with our cooktops. It is best utilized indoors where you can see it as a pale blue flame and then of course can see it at night as a very beautiful blue flame.

Thanks for confirming my assumptions Warren. The gas lights I found were from china and made to be run off methane/biogas. They used a mantle like a Coleman lantern and look to burn fairly bright. Here is a link to the ones I found.

bio lantern

Ray

Warren,

WHen are you going to have the stove and latnerns available? I go to your website and all I can find is the digester plans and digester info. I can't find the stove for sale. DO you guys have anything with a BBQ grill type burner in the works?

Ray

Ray, yes, the Chinese make some very attractive biogas lamps.

Presently we do not offer any type of biogas BBQ, however, any kind of LPG barbecue will burn biogas or you could salvage burners off an old natural gas stove. You could do the same for LPG yard lamps. We are very much tooling up for manufacturing our own cooktops, but in the meantime we offer two burner cooktop imported from Puxin one of China's largest biogas appliance suppliers.

Biogas cooktop

here are some methane resources: http://www.builditsolar.com/Projects/BioFuel/biofuels.htm#Methane

This was a decent build of the style you are going for: http://biorealis.com/digester/construction.html

Thanks guys,

Thanks for the links Abe. Very helpful.

Ray