How to Build an Anaerobic Methane Digester

[tsns1]

Shoulda' known, Vaaders dietary skills involve 'Capturing small Engines, People & Planets'.

[luisthree]

I will make a biodigester, but I'd like to know for example with 5 kg of biomass for how long would you have continuous flame? thank you

[EllenJWard]

Hello, What kind of bacteria do you use to break down the waste? And how do you get hold of it in small quantities?

[LordVaader]

@EllenJWard

The bacteria are anaerobic or found in the lack of oxygen. These types of bacteria are found in animal wastes. You can also get small quantities in a powdered form by buying septic tank treatment powder which contains the same bacteria.

[muzicalman]

is there any welding involved? i'm thinking of building one but i can't use a welding gun to save my life.....

[LordVaader]

@muzicalman

No welding,only plumbing.

[AussieMatters]

One tomato per 55 gallon set up. I might look at wood gas ideas instead.

[alonso336]

How do you take the fertilizer out?

[LordVaader]

@alonso336

The fertilizer is liquid and can be drained out of the valve on the side into the ground.

[alonso336]

@LordVaader

- what can you put in the digester? can you put meat and other cooked leftovers?

- how do you control the liquid level?

- can you add materials every time you want, or do you have to wait until it has processed what had been put before?

thanks so much man, this is great and I'll build one myself!

[LordVaader]

@alonso336

Any organic material including food, newspaper and leaves.

You control the liquid level by draining the fertilizer valve periodically.

You can add materials anytime that you want. Materials will dissolve over time at different rates.

Keys to effective operation are temperature, the warmer the better, particle size of waste product, smaller the better. Good luck.

[Omnimeister]

This is cool! When he puts the tomato in the digester reminds me of Doc Brown in Back to the Future feeding the Mr. Fusion ....questions;

how many gallons of H2O in the drum?

what is your method to capture the methane?

how much psi of methane build up can you capture?

why have the digested product valve at what looks like 18" or so from bottom? Why not closer to bottom of drum?

Thanks!

[LordVaader]

@Omnimeister

1. Drum contains about 20 gallons of water, the rest food waste and headspace for the gas.

2. Gas bleeder valve on top used to collect gas into innertubes. About 3 psi pressure.

3. The waste valve is not on the bottom otherwise it would be too easy to clog with bottom sediment.

4. The digester will make fertilizer and methane but it does not have the 1.21 gigawatts to take you BACK TO THE FUTURE!

[muzicalman]

@LordVaader

IIIIIIIIIIIIIII SEEWATYADIDTHERE!

[elBrechtel]

Hi, is it possible to explain to me how the septi-pak helps? I can't find any information about how it would help to start a digester? Does it contain the methanogenic bacteria culture? thank you

[LordVaader]

@elBrechtel

Septic pack contains bacteria and enzymes that aid in the breakdown of the waste more efficiently. Each pack contains live bacteria for starting your digester. You can also use pig manure if you don't want to use Septic packs.

[elBrechtel]

@LordVaader

Is there any difference between them? why would i chose for manure if i could just buy the septic pak? Are there enough bacteria in a septic pak? thanks for you quick reply!

[Ade4120]

@elBrechtel pig and fowl dunks are the best they are free and esy to get i would even be using fowl dunks cos we have poultry which would be of no waste for me

[LordVaader]

@elBrechtel

The digester is basically a mini septic system. The septi packs populate the digester with active bacteria and enzymes that help break down waste. These same bacteria are also found in manure if you have access to it particularly pig manure. Check out the Rid X site for more details on how the Septic packs work.

[masterfireeater]

can you use baking soda for a small scale version

[masterfireeater]

can you use bakeing soda for a small scale version

[1andyc1]

.be-a-ant.com This site is no1

[chiluba123]

can u buy this anywhere

[tontosplay]

any tips for building a smaller scale version for laboratory research?

[LordVaader]

@tontosplay,

I started out with a windshield wiper fluid plastic bottle with a balloon over the top to collect gas. I placed a waste mix and water into it and set it out into the sun. After a while the balloon would fill up with gas. From this small scale display, I built the larger digester.

[chrisjoneschrisjones]

save the gas dufus

[vox1philippines]

nice biogas digester.... pls watch my first biogas digester project.... pls share some tips .....

thankz

Vox

[renewableenergy100]

good job

[sspence65]

Where is the gas collector?

How are you pressurizing the gas?

[LordVaader]

@sspence65 ,

I don't have a gas collector right now. I have a couple of designs in progress. I wouldn't pressurize the gas due to the amount of pressure and danger involved.

[jawbraeka]

@LordVaader would a small compressor do the trick?

[LordVaader]

@jawbraeka,

Haven't tried compressing the gas. Most people store the gas in air bladders or large tractor inner tubes.

[astrialkil]

@jawbraeka As the gas is flammable you cant use a normal compressor with out the risk of blowing your digester (and maybe house) apart! You need a specialized pump for flammable gasses like they use to compress oxygen. These pumps are expensive. Good luck even finding one.

[CopperFangunlimited]

did you have some H2S filter. some waste can produce a lot fo that (specially marine waste), is a problem with a metalic digestor and is very bad for the electric generator and other machines.

[LordVaader]

@CopperFangunlimited

I don't have an H2S filter, however I have some water columns filled with limewater that act to filter out H2S, but they are not hooked up right now. Should have built the digester out of plastic to eliminate corrosion issue.

[wleathers1]

How and when do you empty the solids or do they all break down.

[LordVaader]

@wleathers1,

I have a drain valve about half way down the side of the barrel for emptying liquid digestate. I usually empty the solids out of the bottom every couple of years and bury them in the garden.

[LordVaader]

@wleathers1,

I have a drain valve about half way down the side of the barrel for emptying liquid digestate. I usually empty the solids out of the bottom every couple of years and bury them in the garden.

[Nepaholic]

Lord Vaader

How much gas do this size of barrel produce?

I look for something that can heat my Greenhouse

[LordVaader]

Gas production depends on a number of variables. Your best option is to build one for the fertilizer generation and look at the gas production as a secondary benefit. I don't know if it would produce enough gas to heat a greenhouse.

[ncbookz]

can you not add the food below the gas line so you dont get any escaping gas?

[LordVaader]

The food is added below the gas line.

[dadigitechman]

I tried to use a plastic barrel with a snap ring lid such as the one in your vid. Mine leaked . Did you make any alterations to the gasket on the lid? What is your aprox. pressure on the digester? Thanx for the vid and your time... Happy digesting!

[LordVaader]

Use a little silicone on both sides of all gaskets to seal them from leaks. The pressure on this unit is less than 5 psi.

[jammerings1]

Amazing. So, how about a digester for dog waste?

[LordVaader]

It can be done. I have a friend that digests his dog waste and fertilizes a tremendous garden with it.

[xMasterTerrax]

Very Nice My Friend do you think it is possable incorporate into your system a Microbial Fuel Cell? Keep the good stuff up.

[LordVaader]

A microbial fuel cell sounds very interesting. The only trouble is it is cold most of the year where I live.

[ncbookz]

@LordVaader how do they clean the gas for use in autos? what do you use the gas for? is it like hydrogen does it explode when lighing? do you need to have a check valve so when lighting it doesnt explode the whole system?

[rigionspm]

I'd like to know how long you wait to drain the liquid. And my opinion is that if we are to use a food disposal or a blender, as long as we dont use the energy grid is alright; other than that we should use something manually to break up the food. I believe that we are in to this to save money and save the planet.Or I could be wrong. But regardless, I admire your work and commend you for it.

[LordVaader]

I drain a little bit of liquid fertilizer out of the unit each time that I add new materials to the digester. An alternate design would be self leveling. You don't need to have a disposal to break up the food it can be done by hand.

[madzi852]

Today i have bulid very similiar digester as you. I used bigger tube for emptying the digester. I hope that it will empty itself as i will add food waste and other stuff. This digester is just for test. If it will work i will use much bigger reservoir.

How much gas do you get from your barrel?

[LordVaader]

They make similar sized digesters like this one in India and they get enough gas to power a stove and lights in a house of 3 people. They also use the digested waste as fertilizer for their rooftop gardens. The key to successful gas production is a temperature at 70F or above and the right mix of waste material, finely ground. Check out the videos of the digesters in India, they even have a digester that eats fish waste from the outside market and powers lights over the market at night.

[ncbookz]

@LordVaader i was thinking the french guy would use dirt to get his bacteria grwoing for 2 weeks then he would surround it by a compost pile of 140 degrees i think they must like 120 degree or something

[marthale7]

EXACTLY what I want to build. Would you change anythng on your design? Why is the spiket on the side mid way up? Thanks you for posting this and do check out Jean Pain. Adding this setup to a compost pile will make this run much better for you.

[LordVaader]

I would change 2 things on my design.

1. Add a disposal to the intake to break up the food products into a easily digested paste.

2. Add a PVC drainfield for the digested waste.

The spigot is half way up so that it does not clog with the settled out solids on the bottom of the digester or the scum on the top. The middle is usually a liquid that can flow out of the valve.

[marthale7]

I have been thinking about using a blender on the front to break up the food for the organisms. Ahhh you are saying food disposal as in used in a kitchen sink nice touch... 2. PVC drain field so would you put this on the bottom of the tank? Interesting. I am thinking of putting multiple 55 gallon barrels together to make a large pool of these, as i don't have a large tank. Thanks for the input.

[LordVaader]

Post your video when you are finished. All of our minds put together can make something really great.

[sbflash311]

It can also be used to power a generator.

[LordVaader]

I will be making a larger version of this digester with a drain field and methane gas capture at my new house in the country by next spring.

[gorrashamati]

Very tidy design and nice video tutorial - Kudos for all your efforts.

we are 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. Thanks.

[Thebigbambeano]

have any problems wit smell

[historymaster]

That's a nice setup. I plan to build my own soon, and I'd like to build a fuel ethanol still as well. If anyone is interested, I suggest looking up Knowledge Publications. They sell a few books on biogas. I don't have any of their books on that yet, but I plan to get them asap. I do have a couple of dvds from them on hydrogen use in vehicles and engines that are pretty good. Anyway, look them up if you want to.

[Magganrchy]

I have researched Ethanol...almost to the point of producing it. What stopped me was the amount of sugar (or fruit or whatever) is needed to make a small amount of fuel.

[VedicHawaii]

How much would you sell one of these things and how much gas does it produce?

[quicksheep]

Well thought out..nice one!

[wenrolland]

Very nice! Please put more videos so we can see how you use or store the gas and the amount of gas generated. Thanks dude!

[Hamish121212]

Are you getting much gas off the digester? Is this your own design?