What is a biodigester and how it works - Biogas basics

First video of biogas basics

[@rod4607]

You’ve been absorbing information for days and finally you find the rock star who makes you aahhhhiiiiiii get it....

[@leefoster4133]

I have been studying this off and on since the 70's. The design in my nut is the following. First the material is feed into a Mesophilic tank where it is kept for about 10 days. It works like the solar city design; sort of as I have changes on your changes. It feeds it's output to a larger tank (1.5 times in volume) to a Thermophic tank where it is kept for 15 days. The reason is based on my research there is microorganisms that like room temp and there are other ones that like it just a bit warmer; 50C-60C as you mentioned. You still get gas production out of both tanks. The first tank breaks down the material sugars as you mentioned. The second tank breaks it down carbohydrates. The output solids and liquid is generally free of pathogens. However, I would use a centrifuge to separate it into liquid and solid no matter what the outlet it comes out from. The liquid has to be exposed to 3 days of sunlight to ensure the lack of pathogens. The solids will have to rot for additional year in sunlight and air in wind rolls. Then it can be safely used as it needs to have the H2S boiled off of it and the sunlight will again kill any remaining pathogens. Now, the way you are handling the gas purification is were we part company. For me, if I had the time to set this up. It would go through a bubblier in water where it can scrub the H2S from the gas initially. You would need a way to add fresh water in at the same time as removing the use water out. And it will smell. The general concept is a distillation column which it is fed into the water to absorbs most of the H2S. Yes, it will/could add some water to the gas but it's also just as likely to remove more than it adds. The column would be for a home setup about 1 to 1.5m and about 16cm wide. It would be filled to 1/3 to ½ of water. As the gas rises through the water, any water vapour should condense and fall back down. It's possible to add condensation collectors at the top of the column. In short, you have a number of tubes glued together that are about 10-30cm long and I don't know around 5mm wide. You are adding surface area to allow the water to condense. Then you just have to exchange the water every day or two. May need an overflow as I think it have more water it it in the process. If you place this column into a water bath then it will decease the temperature and more water and H2S will be extracted. Keep in mind that the H2S will just slightly dissolve in water but any reduce is better than no reduction at all. This step is to really to remove as much of the water and H2S as as possible. Call it a first pass filter. Then you would use the steel swarf and clay pellets for the final product. I was try to come up with a way to use Copper instead to create CuS04. Seems if we used copper powder then would would end up with CuS which wasn't what I was wanting. So for that there would have to be some other steps to be performed to give me CuS04. Well take whatever will serve you out of this mate.

[@TitoTheRaccoon]

I would make a couple tweaks to your design. First, when you have the food inlet tube on the side you have to have a nice and strong seal. Over time, because the weight of the tube and the pressure from the tube getting knocked around when inserting scraps, the seal will probably leak over time. Its just a lot of unnecessary stress on a seal that doesn't necessarily have to be there. The second thing I would change is I would add an elbow to your overflow pipe with another pipe coming straight down a couple of inches. You don't want it to be too long, and not too short. It should be collecting from the center of the liquid. This is because some stuff you put into the digester will float but most will sink. When collecting from the middle your affluent will contain even less solids. If its too long the solids will clog that pipe and if its too high you will collect whatever floating at the top.

[@nickinthefield4202]

Dude you rock! Very in-depth and informative. Respect ✊

[@umarpaillaleo2030]

Amazing work. Already subscribe and waiting more.

[@jasonbrown6362]

I used to work at a class 3 wastewater municipal plant. We had 2 digesters, 1 was the primary where the main digestion took place and the secondary was mostly the finishing off settling tank before removing the solids on a belt press and returning supernatant to the head of the plant for treatment. There's tons of little tid bits of extras in wastewater treatment that isn't included in your digestion talks. Like BOD, "biochemical oxygen demand" for example, and ph for testing proper happy digestion. If theres an unbalance of bugs, the acid producers are overfed and not enough methane producers, or vise versa with not enough food, your ph will be out of whack. If your system works for you, then that's good. I will be building my own digester system using my cattle manure. I will design my system similar to that of what i worked with but on a smaller scale of course. I will have a primary digester with a circulation pump to keep everything mixed up with it being ran thru a heat exchanger. It will pull from the middle of the tank and recirculate back to the top. I'll pull the solids from the bottom of the tank and transfer into the secondary digester. After the "time" is complete, I'll pull the solids from the bottom of the secondary tank and let them dry in sand beds. My main delima with all this is the supernatant, which is like ammonia water, very high BOD content and must be treated properly. Any thoughts on that would be helpful.

[@ndlovukazi5977]

Let me know how it geos I'm very much interested on biogas I grab every information

[@trira1171]

Very informative, thanks...😃

[@lukeschmidtke4400]

Mate this is great keep it up!!!!

[@ndlovukazi5977]

Thank you so much from south Africa

[@markgeurts258]

Great explaination! If started building my own digester from a IBC tank that i've covered with wooden panels and going to fill the space in between with some EPS (styrofoam) pearls. I used your (improved) design, for easy filling and without blokkages of the gasline.

[@mortarriding3913]

Why the EPS foam? Insulation for keeping it warmer?

[@markgeurts258]

@@mortarriding3913 Yes, that's right! It is standing outside beneeth the roof of the carport.. And I'm thinking about heating the water to 30° celcius.

[@mortarriding3913]

@@markgeurts258 have you looked at DIY solar hot water systems?

[@samlenlap]

Thanks for making this it was really helpful I am looking forward to make it for my self I live in India so temperature is not a problem will definitely consider your design suggestions

[@haydenryan441]

Great vid mate. I’m looking at hooking my house up to a digester as I’m on septic system. The digester will be an additional tank before the septic tank. What are you thoughts on this? Air gap at the top is a must I agree. I’m assuming people do it the other way to eliminate potential o2.? Keep the vids coming mate. Cheers Hayden

[@mortarriding3913]

Thanks for the explainers. Regarding using larger biogas digesters to feed electricity back into the grid. I have another idea! How about BioGas as a battery? You mention your concern about heating your digester during cold winters. Have you done the maths to see how much of the energy that you put in is preserved? Think of it like this: If you put in 1kwh from solar, and produce 1kwh of methane* you are essentially storing solar energy for later, while (effectively) sinking greenhouse gases. In this scenario, you would build a solar array that produces more electricity than you consume during daytime in Winter on a sunny day, filling your gas tanks for your generator. Then when you have overcast weather, you consume stored energy. It is in my view more sustainable / environmentally friendly than lithium battery backups, if you can build most of the system DIY and low cost as you have. Though as storage needs go up, you might go into interesting territory with large pressurised gas tanks. *Conversion efficiency of a generator will incur losses

[@leonmalheiros9551]

greetings from Sardegna, thanks a lot for sharing the knowledge! We have moved off grid in June, and slowly improving our little setup, been watching a lot of different videos and yours are definitely the most comprehensive but still easy to understand. i have 2 questions if you have the time: 1) how can we make it work with human waste? we do not have cows at the moment, giraffes are hard to come buy here too, we have 2 sheep but they roam free so not really possible to gather that shit. do you ever empty the tanks completely? or you just keep adding and the overflow pipe kicks off the digested stuff? 2) could you please include on your next video a bit more about the fertilizer biproduct. do you need to do anything to it? or is it ready to be mixed in the soil? thanks keep sending more great videos!

[@itanc1]

Hey dood, nice films I think I have watched them all now and some more than once. I am about to start my first 55gl drum digester. It is a treated steel drum with a 200w heater and is extremely well insulated. Having watched this film I am keen to know if it is safe for the bacteria to keep it at 60 Celsius? My school biology ghost is reminding me that we were taught that bacteria de nature at 45. I am hoping that it’s fine to do this as a shorter retention time offsets the small volume and we are short of space here. I would love to know your thoughts. Cheers. Tanc

[@user-th7cf8ey7d]

blessing from bharat

[@w4447]

So you feed your digester every 28 days or sooner depending on temperature? And how many kilo's do you add at a time? By the way. Another great informative video.

[@johnkilgallon207]

Thank you so much for the content. The sound quality and volume really detracted from the presentation though. Is there any way you could fix this?

[@aicram62]

Make a biogas playlist please and thank you.

[@LexBuildAdventures]

can those septic tank or rv tank bacteria/enzym pucks be used for the starter culture? or would that be the wrong kind for producing methane?

[@thumperhunts6250]

Hey 👋 I'm inspired to make one of these, would you still recommend your latest design in the video?

[@johnsun8791]

Can I store the bio gas in a stainless steel tank to prevent rust

[@uramalakia]

I have so many questions but I don'want to pester You. Is there any good books on the topic that You are familiar with and could recommend? I love Your chanel very much. Thank You for all the amazing content!

[@rosalee33]

I have two books I've been learning from.. "Small scale Rural biogas programmes by David fulford" and A chinese biogas manual. 📚💩

[@thatedoboy1874]

Please what's the outlet for? What passes through the outlet? The slurry?

[@hoosiersolarpower974]

hello i have an 250 gallon IBC Tank that i have turned into a BioDigester if i put a 35 gallon trash can of Cow Manure and 35 gallons of water together as a slurry 70 gallons and 180 gallons of space remaining, how much addition water should i add to the tank all feeder and and exits are on top of tank. Thank you any advice is helpful.

[@rashidmateshi2379]

Iron material can be used to construct biogas!?

[@supplies4reptiles228]

doesn't the pressure from the gas press the feed intake out

[@paulansette6145]

Sorry if you have already been asked these questions eleswhere. What wattage heaters are you using?

[@davidoutdoors74]

How are your two digesters doing, still producing lots of biogas?

[@danieltaurins86]

Yer mate still producing, more than I’m using at the moment.

[@robertpoynton9923]

G'day mate. Im looking at building a digester but trying to work out if its right for me. I have very little food waste so one question would be how often do i need to "feed" the digester? Also would i need someone to feed it if i was to go away for a week or so?

[@danieltaurins86]

Hey Robert, it is depending on size of your digester of how much and often you feed. With the 1m3 IBC I try to feed a bucket of food every 3-5 days, you can feed more regularly, also if it is up and running fine and has been for a while, I wouldn’t worry too much about going away for a week, give it a feed before you go.

[@robertpoynton9923]

@@danieltaurins86 i appreciate the reply mate. Is there a Facebook group or reddit that i could join to gain knowledge from a community of biogas people?

[@majidraza4969]

but i need help

[@aussiefarmlife3366]

Gday mate I’m building a digester currently on farm for pig effluent management Using old milk vat system I’ve been following your vid’s Would u be interested in coming out and you could give me some help Would b great for your channel too

[@majidraza4969]

sir i have made also

[@FightFilms]

Bacteria, not pathogens.