anaerobic methane digester how to, including biogas scrubbing

[Rain4Fuel]

good video man, Side note....H2S is called Hydrogen Sulfide, not Sulfur Dioxide. Keep it up.

[dadigitechman]

Hey I use lime water to remove co2. Does it work for h2s as well? Right now I'm using iron chips from a machine shop for h2s removal. Finally silica gel for desicant. Then I use a refrigerator compressor to store the gas in compressor tank. Works nice, that way we can regulate the pressure back down and use the gas for pretty much everything. Oh ya, I llike the drawings. Wish I had a buck for every one of those I made. xD Looks good though!

[HomeDistiller]

@dadigitechman i think it would as the H2S is an acid, do you have the iron before or after the lime water scrubber? if you have it built i would keep it in the system just put it after the lime water. my plan was to compress the gas to i need to rebuild the system though because i used a steel tank that lasted about 1.5 years

[luisthree]

I will make a digester, but I'd like to know for example, with 5 kgr of biomass how much time of flame would I get?

Thank you.

[HomeDistiller]

@luisthree it depends on what size flame you use.. i was adding about 1 kg a day and was getting 50 ltrs of gas a day.. make sure you use a plastic tank otherwise it will rust through very fast as mine did

[nisha8759]

hello...great effort...may i know is there any solvent for methane?since my uni gas chromatography only inputs liquid form,i need to chnage the methane gas that i form from the waste into liquid form..so,do u know any solvent for methane?

[HomeDistiller]

@nisha8759 water will dissolve a small amount

[MrScorpion051189]

Hi, v.nice video. Thumbs up. I am currently constrcting a digester for poultry dung. Can u explain to me how can i couple a small 6kg gas tank to my set up instead of directly delivring z gas out. My concern is about pressurre in the system.Can u please guide in how the steel wool would help remove SO2 from the system. I shall use the lime water as recomnded by u. R u interested in SCADA systems for the remote control of the digester(3rd yr projct). I will be posting it soon.Thanks a lot :D

[HomeDistiller]

@MrScorpion051189 you would need need to compress the gas after removal of the so2 to use the steel wool all you need to do is flow the gas through it and wash it every few weeks, the lime water will remove the SO2 too. you need to make sure you have purged the compressor and any gas lines etc of air

[MrScorpion051189]

@HomeDistiller the pressure throughout the system, i.e in the storing gas tank, the pipelines as well as the anaerobic chamber will be z same order. I would like to couple a pump to pull out the gas at a low pressure in the pipes to a high pressure in the gas tank. Any guidelines on this would be mostly appreciated. Can u plz, plz snd me some calculations u did, if any, before z construction of z digester which wil be v. helpful for my project. thanks.... :DDD

[HomeDistiller]

@MrScorpion051189 i made no calculation just read some old books on the subject ("producing your own power" 1974 rodale press), i wouldnt suck from the digester because if you have any leaks you will draw in air to the mix and you could have a nasty explosion. your better off storing some under a small amount of water pressure then compressing from there

[MrScorpion051189]

@HomeDistiller thanks a lot for your video and assistance. Best continuity :D

[keemskie123]

How is water related to your study?

[aryan87samad]

@homedistller..

hey man,, i just want to know the scrubing method u are using, i have read your comments, but didnt got the exact i dea of the scubber u used,,plz elaborate that...

[HomeDistiller]

@aryan87when H2S dissolves in water it makes sulfuric acid, when CO2 dissolves in water it makes carbonic acid.. so if you make the water very alkaline then it reacts with the acid and makes salts so all the gas that passes has had most of the nasties removed

[aryan87samad]

@HomeDistiller

thanks for the rply

i didnt get the idea of the steel wool u are using??? i know how the reaction occurs,,, but i want the technical detail of the scrubber DEVICE u r using...plzz help me out with that ...thanks again!

[HomeDistiller]

@aryan87samad the steel wool will scrubb the H2S its just packe into some pvc drain pipe thats sealed so the gas must pass through the wool to reaction.. the alkaline solution will cause the same results

[aryan87samad]

@HomeDistiller

oh,,wow,,we just have to pass the gas through steel wool,,and all the H2s will be removed ??? :)..really??

[HomeDistiller]

@aryan87samad aslong as its not stainless steel then yes.. a trace will remain but most will be removed.. you will need to wash the wool every month or so though.. and pack it pritty damn tight

[aryan87samad]

@HomeDistiller

wow..! is it really so simple??i mean we just have to pass the gas through steel wool,, and the h2s will completly be removes and the gas is safe for power generators??

[slivace]

can you use just a cow urine for the biomass and if you can do you think it will be more effective.

[HomeDistiller]

@slivace nope, you need carbon as well, that will just add nitrogen, you need much more carbon than nitrogen

[magna59]

From the steel scrubber to the water scrubber why not run the tube in from the top and down to the bottom of the drum & use water as a seal, rather than having to find a mechanical valve.

[HomeDistiller]

@magna59 you could do that but with mechanical valves it stops any reverse flow

[ak47citizensoldier]

oh thanks

[ak47citizensoldier]

sorry to bother you but why must the CO2 be removed?

thanks

[HomeDistiller]

@ak47citizensoldier the co2 is not really a problem its the H2S that is but removing both means you have more energy per ltr of gas

[CRAMsuper]

i also want to make one. can i have a copy of the materials that you used in that digester???.

[HomeDistiller]

@CRAMsuper if you have a read through the comments you will find everything you need.

[thatstheone87]

If you have pressure building up to push the water to the elevated tank, would the pressure push the biomass out of the filling up pipe when you took off the cap?

[HomeDistiller]

@thatstheone87 thats what the check valve and the tap on the output is for. and you open the side vlave first to let out some old bio-mass first

[HomeDistiller]

you will need to make sure you keep it at a stable 37°C for best production, and a good mix of fresh animal poo (for some bacteria start say about %10 of the mix) and some sugar and vegetable products, that should give you an ok yield once the small one has started and going well if you scale up use the slops from in the small tank to get a head start on production (it will take upto 3 weeks to start fully on a large scale otherwise)

[matthew18452]

@HomeDistiller why is 37 degrees such a good temperature? Is warmer not better?

[HomeDistiller]

@matthew18452 37°C is the ideal temp for the bacteria that produces the gas.

[burzum19861986]

@matthew18452 you can operate an anaerobic reactor at higher temperatures (termophilic range), but the process become more unestable

[KLpyro]

For school, we need to do a science project....

My friend and i were thinking about a very small scale biogas generator...

Can you give us some tips? (we won't combust the gas, we'll use it as a heat source)

For example: whats the best biomaterial to use, should we use yeast,sugar,water,...

We'll start with a small scale test, just to prove the concept (2l bottle) and crank it up to a 10l tank or more.....

Thanks anyway ;)

[anthony20807]

Por favor pueden subir videos sobre los biodigestores.Gracias

[jawbraeka]

1:46 to 3:28 are the plans to world domination (with instructions) lol

[URAconstructor]

@jawbraeka the same thing we do every day Pinky, try to take over the world!!!!

[TemplarX2]

You should soda lime instead of water; it's more effective at removing CO2.

[HomeDistiller]

@TemplarX2 if you read the other comments below i have already discussed this many times. any alkaline solution will work

[SolarizeYourLife]

I like the big input, in the center idea, because you can add a big mixer/stir to spin the whole bottom settlement. Do you have something to mix with?

[HomeDistiller]

@SolarizeYourLife a long mortar mixer works quite well i use a sharpened one to chop it input feed for the tank also

[SolarizeYourLife]

@HomeDistiller I sorry, I meant the stir up the settlement at the bottom of the barrel, from getting thick and hard and keeping it liquified.

[HomeDistiller]

@SolarizeYourLife yeah a long mortar mixer, the problem is you dont want to introduce to much air or you will produce CO2

[TriciaGreenfinity]

Hi there--great video, thanks for sharing your design! Where did you find the material to scrub the methane gas? I'm building a similar model and would love to know what/where to buy scrubbing material. Thanks!

[HomeDistiller]

@TriciaGreenfinity steel wool for a hardware store. or bubble it through an alkaline solution, or use a combination, the steel wool will remove the SO2 and the alkaline solution will remove CO2 and SO2

[conkoumis]

how do you add waste without letting the gas escape?

[HomeDistiller]

@conkoumis the tube in the centre goes under the liquid level, so you just unscrew the top and add you slurry then screw it back on, it will get a small amount of air but not enough to worry about

[HomeDistiller]

i dont have any plans as such.. but i might make another video discussing thing that i would change and other ways to improve the system

[roberttobys]

Fantastic idea. I've also searched the web for biogas digesters and yours came up as the best solution. Do you have plans that I could get from you? I'd be happy to pay any cost to you.

I'd like to setup a similar unit here in Portland, Oregon for use with a wall mounted propane heating unit.

My father and I were just discussing corrosion of the steel barrel. Then I read your suggestion on a plastic drum. This would allow for long term use as opposed to having to rebuild every few years.

Thanks!

[blkcola]

@roberttobys - You can also run gas engines on fermented whiskey mash heated to 180 degrees (heated by exhaust pipe); basically a Vapor Carb concept.

[ShaggtyDoo]

Thanks for explaining - especially the cleaning part.

If i am just using biogas for burning in camp stoves (and maybe a LP gas fridge) do I need to bother cleaning the gas? I assume the acids are caustic?

[HomeDistiller]

@ShaggtyDoo if its just a gas burner then i think it should be fine, but to keep the fridge happy i would scrub the gas of HS2, steel wool will do the trick (not stainless steel wool but the rusting kind) HS2 when dissolved in water makes sulphuric acid so its very corrosive, this is also why i am now recommending to ONLY use a plastic drum for the fermentation chamber as steel get pin hole in it real fast, also you will need to change the jets to use this gas as LP has alot more energy in it

[HomeDistiller]

@ShaggtyDoo (continued) so you need at least 4 time the amount of gas for bio-gas, as for the gas stove i found it will burn quite clean with just a open pipe

[t1l1m]

(continued) to put this unit together. I have found a couple of 3 figures before the decimal parts that would work, but I was hoping to keep the price down to less than what one of those connectors cost. Welding is an option - if that is what I have to do. Any thoughts on where to get and have shipped to the Americas?

[HomeDistiller]

@t1l1m have you looked on ebay? you maybe able to use large tank flanges (like the one on the side of the digester but much larger and you could add a large ball valve instead of the screw cap)

[t1l1m]

@HomeDistiller, I'm quoting you on part of this video (I hope your still responding)

"I used an 100mm pot, that's just a floor flange, I've glued to it drilled full of holes (??) run through the steel.

I've read through the remarks/replies about what the device is your using on top of the barrel. You have a cap that is threaded, a stand pipe (threaded male) glued to what looks like a closet flange. I have typed nearly 100 different search terms/phrases trying to find parts (next comment)

[Flipbounce]

Wow, you have one of the best digester's on youtube. Thanks for showing us your scrubber idea, I would have never even thought to purify the gas coming off. I've got most of my parts ready to put together. Where did you get your barrel?

[HomeDistiller]

@Flipbounce the scrubbers work as long as they are not stainless, but i found in my research that lime water or a caustic solution will work better as it will also remove some CO2. the barrel i got from a feed store but get a plastic one as the steel ones rust out real quick from the H2S

[demios99]

Removal from fuel gases - Hydrogen sulfide is commonly found in biogas.

Reaction with iron oxide- gas is pumped through a container of hydrated iron(III) oxide,which combines with hydrogen sulfide. Fe2O3(s) + H2O(l) + 3 H2S(g) → Fe2S3(s) + 4 H2O(l)

In order to regenerate iron(III) oxide, the container must be taken out of service,flooded with water and aerated. 2 Fe2S3(s) + 3 O2(g) + 2 H2O(l) → 2 Fe2O3(s) + H2O(l) + 6 S(s)

On completion the container is drained and reused.

Source - Wiki

[HomeDistiller]

@demios99 lime water will also work and it will also help remove CO2 as they both (CO2 and H2S) produce an acid when dissolved in water

[ncbookz]

i just had a better idea! for 8 cent per day you can have an electric blanket keep the temperature up in the winter and you should be gaining more than the 8 cent to keep it at 90 degrees F. i think 13 gallons of methane is worth more than 8 cent per day 1000kwatts of power from the power grid! .08cent/kwhr

[HomeDistiller]

@ncbookz that kind of defeats the whole purpose, i was planing to heat the tank using gas produced through some peltier devices (or TEG's) and make some power at the same time as heating the tank.. you can get more gas from vegetable materials than manure as it has more available energy in any carbohydrates in the vegies. the only problem is getting the nitrogen up enough, fresh bird poo would be very good for this or just urine

[ncbookz]

if you add some manure you might double your 13 gallons per day, also if you add a small gas line out of the top and have a small portion heat the tank in the winter you will have the steady flow of gas you desire. in other words have 2 gas hoses one for heating the tank underneath itself

[ncbookz]

i just had an excellent idea! YOU COULD USE THE PRESSURE TO RUN A MOTOR LIKE AN AIR MOTOR. HOW MANY PSI ARE YOU GETTING? PLEASE

[HomeDistiller]

@ncbookz not much as the tank would pop open at about 2-3 psi

[jhillsmo]

@HomeDistiller afternoon- got my digestor built this weekend. i was able to start with 5 gals of chicken poop and food scraps. about how long does it take for process to begin? i don't have burner attched yet so i put a small balloon to watch it inflate as gas is created i did use a plastic drum. Is that good or bad?

[jhillsmo]

@HomeDistiller also i have seen videos where they change modify the orifice on the burner to accept the methane. i was thinking of getting a bunsen burner to burn the gas off so that i can have some metrics on how much waste produces how much gas and will burn x amount of time. would i have to have a methane burning bunsen or just any bunsen?

[HomeDistiller]

@jhillsmo im not sure its a strange gas and seems to burn very cleanly straight off the hose without any oxygen mixed i think the pressure would be to low for a bunsen. just use a piece of copper pipe to start with

[ncbookz]

excellent!

[HomeDistiller]

50 ltrs of gas a day is the most i got.. if you can maintain temp and a good feeding plan you should get at least this maybe more... but heating is the problem,

[ncbookz]

@HomeDistiller maintain the temperature with a compost pile around the unit! or use a small portion of the gas to heat the barrel have 2 gas lines from the top one to keep a constant flame and another to supply your appliance

[ramirezk2]

How much is the biogas production for this system (volume)? I mean for example after 50-60 days.

[HomeDistiller]

@sumedhbapat9 i tend to disagree.. this design worked fine, although the drum should be a plastic one and it should have some temp control. it worked great.

[pamplona1067]

que bueno que hablara en español

[jhillsmo]

Love this, getting ready to disconnect from utility systems. Am I understanding your comment about cold weather, it stops production? Our winters here are 0 to low teens, wouldn't breakdown of organics continue?

[HomeDistiller]

@jhillsmo no at 0 it will stop completely you must remember it is bacteria that does the break down the colder the slower they work the best temp is 34-37°C

[ncbookz]

@jhillsmo hey friend if you surround your tank with compost pile in the winter it will stay the 100 degree f you need. 140 degree is a typical compost pile temperature. a man did this 9 months out of the year and it worked i saw it on youtube somewhere

[Cstrife234]

Actually, if you put tubing coming down into the water, you wouldn't need a valve. It would just shoot the bubbles out and water wont come back up, nor will oxygen get in.

[HomeDistiller]

@Cstrife234 not when you open the top of the digester to feed it, the back pressure would push the contents out the top.. you would need at least a valve, the one way valve is just an extra safety

[Cstrife234]

@HomeDistiller I never had that problem, but I'm not disputing you either. At the least you could put a shut off valve for the hose going into the water and turn it on when you are going to open the digester. :D

[kelpend555]

GDay mate. Im going to build one of these at some stage. Do you know where I can get some plans and why does the pipe run from the lid to almost the bottom? Also why is there a reducer on this pipe?

Excellent work. Thanks for posting.

[HomeDistiller]

there is no reducer on the one i made. i did draw a reducer in the plans but didnt use one.. it goes to the bottom because you dont want air entering the chamber as it anaerobic(without oxygen) not aerobic (with oxygen)

[Nepaholic]

Hi

how much gas does this size produce?

Jens

[HomeDistiller]

you haven't read all the comments have you?

[chardnj]

why the inlet pipe..is to long?

[Duboisi]

For the gas going into the drum with water, you may consider a one way valve and a knee joint. pointing downwards to minimize any flushbacks.

[HomeDistiller]

that was mentioned in the plans :P

[Duboisi]

Maybee I missed something, but it seemed like the pipe was more at a slope. While a proper 90 degree bend will stop the flushback much better.

Great project though. I have no qualifications in the area, but urge you to take security precautions. -These things can be dangerous you know.:-)

[ncbookz]

@Duboisi i was thinking this as well ,, would a 90 degree bend inside prevent anything from being pushed back up? that would probably work

[machellebice]

Also you are not using a pressure gauge to keep the proper pressure instead of guessing. You also need a sent to add to it to be able to smell it if it leaks like natural gas.

[machellebice]

Ok, I see several very unsafe problems you have with your idea. The idea is sound just the wrong equipment. First you are using the wrong tank. An oil drum will not withstand the high pressure from forming gas. That is why there are special high pressure tanks used to store methane. Then the pvc, in using gas you use metal high pressure pipes and fittings. The pvc will not hold the pressure and the gas will eat through the line.

[tonymac96]

I agreed on this...This equipment is OK for I will say 30 to 100 inches of water ( no more than 4 psi) ...higher than that...and the drum will bulge..or something will break (not good). I have done the same with a HDPE drum and a 60 inches water column as a vent valve !!! it works pretty good !!!!

[FutureNews2point0]

Will this digest governmental BS? We have enough to power the entire world here in the USA.

[321gocog]

thank you for taking the time to share your plans, I do hope that you will post an update once you have completed this project.

[DominickBlack]

5 stars to you!

[sirHOAX]

Wonder if you can pump down this gas to a high pressure. Would be great alternative if you can get to use it everyday. Any clue if this is the case?

[HomeDistiller]

you can (and i plan too) useing something like an old fridge compresser, but you cannot liquidfy it unless you can get to realy high pressures (and very low temps) but just commerssing it is easy... although to save the tank and the compresser you need to scrub the gas

[marthale7]

Yes you can. Jean Pain did it look him up for composting, he made this gas in the center of a compost pile and ran his car on the compressed gas.

[ncbookz]

@marthale7 yes he used the compost pile to heat his house and he used the gas for cooking! right on!

[wormswood22231]

Question: Can you put normal food scarps ie, cooked foods, gravy, bones etc., into a digester?

Also how long does the process take (practically), before you have to empty out the reaction vessel and recharge it?

[HomeDistiller]

i wouldn't put bones or to much meat as it makes it really smell and the bone wont break down.. mine has been running for a year and i haven't had to empty it, this is a continuous type you feed it every few days and remove the same volume as you put in from the tap in the side

[Cstrife234]

I've seen them do methane harvesting in China. All they do is have terracotta pots in the ground, all piped together into the house. They put the pig manure and vegetable matter in the pots and pipe the methane right in, as is. It works very well. I don't think you have to worry about the co2 too much. If you're going to be burning it, you might as well have some plants in and around your house anyway.

[HomeDistiller]

scrubbing the CO2 out just makes the fuel burn hotter, and also makes it easier to run a generator on, and less gas to store for the same amount of energy

[Cstrife234]

Oh, not disagreeing with you at all. Just saying how simple it all actually is.

[cathairinmyfood]

Seen it too. They just drop a tube into the pit where they shove the pig poo and run the tube directly to the stove.

[SARKOZETTES]

black paint  would be better.

More heat for the mixture inside.

[HomeDistiller]

it is painted black now :)

[vibeslord]

nice plan!

[hot2warm]

Looks good. But since this is anaerobic, you will generate hydrogen sulfide instead of sulfur dioxide. Also, is the drum lined or coated on the inside? I am afraid that you'll get massive corrosion with it being an acidic environment.

[HomeDistiller]

its a food grade drum so its lined with plastic.. hydrogen sulfide doesn't matter ether it will all be scrubbed out via being bubbled through an alkaline solution

[jayceepark]

hey,does the methane have to be compressed at 500psi to liquidfy into usable gas, to transfer into bbq gas bottles for example?

[HomeDistiller]

at 500psi it will still be a gas... it would make storing some smaller but if you look at my design for the system the water will push the gas out of the storage tank so it can be used

[jayceepark]

oh sory i meant 5000psi compression, liquefying the gas...

[Magganrchy]

it takes 1000psi to compress methane

[HomeDistiller]

At -82.7 degrees centigrade it would take a pressure of 45.96 bar to get it to liquify (about 670psi) but it will NOT liquify above -82.7°C

[gorrashamati]

I'm also looking to build one of these ... but first, does anybody have a link as to how to modify LP appliances to operate properly with the methane that comes from the digester? We already have all LP appliances, not natural gas, I've read references that the oxygen feeds are different (?maybe other factors also). Thanks.

[ncbookz]

@gorrashamati i ordered an lp bunsen burner as soon as it comes in i will be doing some test to see if it works go get you a propane torch from the hardware store and try it

[smellex1234]

heya mate. Cool setup i am well impressed. Did you make those plans yourself?? and if so would you be willing to share the love??

[HomeDistiller]

yeah plans are my own although the digester itself is not my idea i used the idea from a guy on youtube.. but he was venting to the air

[yourroaddog]

the pipe with the steel wool instead of going into the bottom of the water tank come in through the top with a long tube and you will not need a check valve or have pressure problems

[HomeDistiller]

there is a reason for haveing the pipe at the bottom and its to help remove some CO² i may even add a small tube the has lots of holes to make the bubbles smaller

[shaunhh]

how did you go with this? Are you capturing decent amounts of methane?

[HomeDistiller]

it depends on the temp i get about 50 ltrs a day in warm weather but if it cools down bugger all

[cathairinmyfood]

what can you do with 50 ltrs a day? i'm curious because I've switched to a vegan diet and home and have all sorts of fruit and vegetable scraps leftover.... :-)

[HomeDistiller]

cook your vegan food with it? just get a natural gas burner and away you go

[cathairinmyfood]

i eat it raw :-) but how about heat? i just have no idea how much 50 ltrs of gas a day really means as far as heating my home, heating my hot water heater, etc... :-)

[HomeDistiller]

not much.. 50 ltrs would cook one meal and i only get that kindda amount in the summer, you will also get much more energy from cooked food than raw :P

[cathairinmyfood]

i beg your pardon. i get huge amounts of energy and nutrients from eating raw food! much more nutritious than the meat and potato diet! :-P

[HomeDistiller]

technically no but I'm glad its working for you i know i couldn't do it.. maybe veggie but definitely not all raw.. in a chef by trade and you can do allot more with veggies than just eat em raw :)

[cathairinmyfood]

i don't know about that. it's true that it's 'new' but have you checked out some of the raw food books? i'm looking through 'ani's raw food kitchen' and hope to whip up some recipes soon. and there's the added benefit that you will have loads of veggie and fruit scraps for your anaerobic distiller. i have so much that's how i ended up watching your video. i'd like to do something with them rather than just send them to the local dump. :-)

[davidwillis1690]

Thanks for sharing... It looks like a nice design, But unless I am missing something, you will not be able to produce the pressure to push that water into that last barrel... If you do generate that kind of pressure in the tank, you will run into problems with stuff coming out your input. Although, I may be missing something, I new to this, and just learning... Again, thanks for the video.

[HomeDistiller]

as all the outlets on the tank are valved or sealed there will be no problem with it over flowing (have a look at the second video). before i add more bio-mas to the digester i will open the side valve till all the pressure in the tank is released (and spent slurry) and then open the top and add the new slurry

[davidwillis1690]

That makes sense, I knew I was probably missing something. Does the spend slurry raise to the top, or bottom?

Anyway, I look forward to more videos.

[HomeDistiller]

as far as i know it doesn't really raise or lower.. so you will always lose some undigested stuff with it.. thats why in commercial plants the spent slurry goes into a smaller digester for secondary fermentation