How to build biogas scrubbers at home
Getting my biogas scrubbers working is one of the last tasks in my new setup. I have always wanted to have the scrubbers and gas storage in the strawbale shed but until now it wasn't possible. With space now available I took the chance to upgrade the biogas scrubbers one more time, hopefully it will be the last. I really like these as they are easy to change, you can see in side them and they are relatively simple to install.
Scrubber 1: Water
Scrubber 2: Cat litter (any desiccant)
Scrubber 3: Iron wool
Materials list
2 x 3/4" Male BSP connectors
2 x 3/4" Male BSP to 25mm PVC adaptors
5 x 3/4" Female BSP to 25mm PVC adaptors
1 x 25mm PVC elbow
30cm 25mm PVC pipe
3 x 3/4" Brass male BSP to 8mm pipe
3 x 8mm to 4mm brass pipe reducer
2 x 3/4" Brass male BSP to 1/4" BSP
2 x 8mm barb to 1/4" BSP female thread brass coupler
1 x 8mm inline gas valve
3 x 10" Aquafilter inline water filter housing transparent 3/4"
Chapters
0:00 Intro
1:32 Moving the gas line
2:50 Scrubber materials
4:52 Putting scrubbers together
7:22 Inlets and outlets
8:30 Wall mounts
9:03 Mounting to the wall
9:45 Linking it all up
11:04 Filling the scrubbers
11:25 Moving in the gas bag
11:41 Opening the valves
I enjoy your videos each time, and you seem to always find a good second use for items. These filter housings are ideal. Well done. Keep it coming. -M
Thanks very much. Yes they are! Look really nice as well. Cheers
The Scrubbers are so cool. Good job mate!
Thanks 👍
Parece un excelente biodigestor hecho con mucho entusiasmo. Estoy pensando en seguir tus pasos para hacer uno en casa. Saludos desde Argentina y espero que puedas volver para ver los resultados.
Oh ok, I actually did not watch the full video, before asking the question. Now I understand everything. Thank you once again.
No worries!
He has the scrubbing backwards
You need water wool then litter
Thanks for nice explaination brother
hey there, excellent video. Just wondering how often you need to change your filters? Was wondering if you had an estimate for the throughput?
Good job mate... Consider adding three more cylinders to clean up some final residue. The idea is a six-stage scrub system; 1) H2O to remove CO2 2) Silica Gel to remove H2O 3) Steel Wool to remove H2S 4) NaOH solution to remove Sulfer (from the wool) and CO2 5) Silica Gel to remove H20 (from #4) 6) Activated Carbon to remove final trace CO2 & H2S These steps should increase CH4 concentration from 43% to 55% (15% power increase).
Interesting! Question, could you not replace the H2O with NaOH solution and the Silica with activated charcoal? Two birds in one stone kind of thing?? Cheers
@@GetMeOffGrid_ - I'm sure that would help as well. My understanding is that removing single elements per stage is simply more effective...
Hi from Britanny Why do you say that the process with 6 scrubbers could increase the concentration of CH4 from 43% to 55% , when the concentration of non purified biogas is 60% ( more 39% of CO2 + 1% of H2S ) ? So you could increase from 60% to how ? And what is the grade of efficiency with the scrubber filled with NaOH ? Cordially JF Louarn
@@mercermouth7571 Hi from Britanny Why do you say that the process with 6 scrubbers could increase the concentration of CH4 from 43% to 55% , when the concentration of non purified biogas is 60% ( more 39% of CO2 + 1% of H2S ) ? So you could increase from 60% to how ? And what is the grade of efficiency with the scrubber filled with NaOH ? Cordially JF Louarn
@@jflouarn1945 From what I'm reading, (I don't have the equipment to actually measure each component) the goal is to remove as much of the CO2, H2S, & H2O before storing/burning the CH4. I imagine that the original concentration of CH4 may also depend on the source of fermented materials. I'm fermenting Duckweed and house waste but no ruminate dung. The bottom line is to clean the gas as much as possible which will help prevent corrosion of metal fittings/appliances and simply burn more efficiently overall. I've seen plenty of examples where no scrubbers were used at all...
You are great sir
Thanks very much!
Any news on this build? Looks amazing, would love some stats on production.
I enjoyed the video. What thickness is the gas holder ?
Any update on gas production? Great looking system. Hope you can get the time for another video soon.
Not yet, unfortunately. I am no longer living at the property where I made this. I am hoping to go back for a week in June. Then I am aiming to get a video sorted on how it has fared over the last year and hopefully some gas. Thanks for checking in.
Thank you for the informative video, you are a great man! I understood all your teachings about the mechanics, but where I am lost is , apart from tubes inside the water filters, what else did you put in that does the scrubbing? Thank you 👍
Water in the first, cat litter (or activated charcoal) in the second, and iron wool in the third
I have seen you have 3 different types of scrubbers now, why not use them all? More purification is the objective, right? I do like the air stones idea, as well as being able to see in the filters as to what's going on. Is there a way to measure what you wind up with?
Nice work. Did you also think of adding your toilet waste to the biogas production? I would love to build such system eventually. If you will, I would love to see your process. Much love from Mexico
I have thought about it but I don't have the property to do it at the moment. Hopefully in the future I'll manage to find somewhere suitable to experiment with things like this. Saludos
Good job but how can I learn about it from the starting to the end
After purifying the methane gas, does it make the biogas better for compression into cylinder???
Nice video, thanks for sharing Will this setup requires any Flashback arrestor? 🤔
No, the water acts as a brake.
Hello well done. I have worked in energy producing plant from landfill area but we dont have scrubber for Co2. We remove the siloxane with silica gel. I have wondered some things about your purification of biogas. How it works efficiently? Have you ever been any checked your contents of bio gas? Also reaction of scrubber how long time it takes and what is the pressure of flow from digester?
Not sure how efficiently it work tbh, looking at details online I expect ~50% removal of impurities. The pressure is minimal.
Hello, best scrubber I have ever seen for gas! Question, what is the best storage container or bag to use for collecting the gas in.
I'd say bag, if you are going to use the gas regularly. If not then compress from a bag into a cylinder.
Air mattress
i would recommend trying to keep all tube accessories plastic until the end of the filter as you are using the iron wool to remove metal eating gas?
Good point! I hadn't thought of that, but makes perfect sense. Cheers
Hello, can i ask you what types of materials used as the scrubber material .i enjoyed your video . thanks
Water, cat litter and iron wool
The h2s scrubs better with humidity so you should go through the water then the wool then kitty litter
Thank you for sharing your knowledge. It’s such a great resource. My question is on clip 7:00, did I hear you call it bubble rocks? What are there for? I thought the idea is to allow the gas into the very bottom of the filter and out from the top. How does it work with the bubble rocks blocking the gas? Thank you. I will definitely experiment making biogas by building a biodigester. In case you’re wondering about why I’m so interested. I currently a post graduate student of environmental science and my concentration is in Global Environmental Policy and Management. It’s very fascinating to know what we can do with our own waste right from our homes. Thank you in advance for your response.
Thanks! The bubble rocks are to increase the surface area of the gas as it travels through the water. Meaning that more impurities will dissolve in the water. Good luck with your studies!
Hey chap, how’s it going? Having watched your films (and quite a few others) I have built one and burned its first gas today! Yay. It’s only been 9 days and I was not expecting it so soon and as such I have no filters or storage built yet. I would love to know how long you have run them and if you would recommend them. I have heard the steel wool filter is better mounted horizontally so the crumbling steel wool doesn’t block the inlet, any thoughts? Also and of extreme interest is an episode of 39 ways to save the planet (bbc r4 if you don’t know it) where they put damp wood ash in a plastic bottle and inject co2, a reaction occurs, the ash turns to pellets as it takes up the co2 and the bottle collapses as the gas is consumed. The pellets are then used as aggregate. I am keen to try this as soon as I possibly can. As my digester stands I am collecting in an inverted pint glass in a box of water which I intend to replicate in the morning on a 150l scale and I wonder if passing the gas through as much of the water in the box as possible before collecting it the floating drum would remove co2 as well, what do you think? Incidentally I am heating it with a 200 w 3d printer bed heater which along with substantial insulation is keeping it warm for very little power. Anyway all the best. Tanc
Hi Tanc. All goo here thanks. Not getting enough time to spend on fun things at the moment though. Great work on getting gas so soon, what did you use? Pure cow manure? I haven't run my scrubbers for long, one month so far. So far all I can say is they aren't leaking and they allow for easy checking of gas flow. That sounds interesting, I wonder what the reaction there is?! Let me know how it goes if you try it. Passing the gas through the water will remove some CO2 and a little H2S as well. It will mean your as is a bit "wet" but if you are not using a metal container for storage I don't think it will be too much of an issue. Interesting heating system. I'd like to down power my heater, I've got to get my temperature probe set up first so I can monitor the effects! Lots to keep us busy! Take it easy.
@@GetMeOffGrid_hiya I started it with 60lt straight from the slurry tank underneath the cows on a dairy farm. Farmer said the whole 180000gl tank is already loaded with some bacteria for breaking up the crust. I was slightly concerned that this would be counter productive but all good in the end. The only thing is I have no appliances to run from it. What do you use your biogas for? Is it easy to convert a camping burner? I am desperate to at least make my coffee on it as soon as possible. Also how much gas can be produced from a 55gl system. Also (sorry) have you ever run yours in the thermofillic range of 55-60C? I have read that retention time is much less so presumably lt/hour goes up? Anyway, back to it 👍
Any luck with the gas? What are you doing with your scrubbed gas in the bag? Are you going to use it to generate electricity or something else? Did you build a water heater to get the temperature up in the digester? I have a lot of grass and am wondering If I'd be able to produce bio gas from it. Hope you've not given up?
How are your systems doing??
You should add an activated carbon filter after the steel wool. My understanding is that it removes VOCs. Cleaner burn and you don't have to store them in your gas bag.
Also should consider adding a condenser to remove water vapor(perhaps mason jars in a water bath. It might work) after the water and before everything else.
ALSO ALSO I'm pretty sure that you want a base in the water to remove acids. Bleach should work. Water alone won't do much as it has a neutral PH. Plus there is already water vapor in the Biogas.
Good day. I hope your research is going well. Can you please list the materials used for this purifier? Thank you
I've added the info to the description.
It looks great although I think the bubble rocks in the dry cylinders work against you. Those bubble rocks can have pretty high back pressure, and since there is no liquid/gas interface, there is no advantage to having them. Hypothetically, in an extreme scenario where we have lost the grid, we will run out of steel wool, and cat litter. If it's the iron oxide that neutralizes the H2S, then could soil high in iron oxide content (really red soil) be used? I can't think of any natural dessicants...maybe do it with a cold trap? Anyway, that's a very clean installation. Subscribed!
Good point. Not sure why I put them there to be honest. Got an idea in my head and ran with it without thinking about it probably. I imagine that if you ran it through three water scrubbers you would remove most of the impurities that way. The dessicant would be the issue. Charcoal could work, or if you get silica gels you could remove them, heat them up to "reactivate" it after they are saturating and then use them again. A bit more work, but if the worlds ended I'm sure you'd have more time to do little jobs like that. I am hoping to get back to the house it is all installed in and give it an overhaul in the next few months. Hopefully I can then report back on any issue or successes. Cheers!
Please, help me by listing the items in the other bottle aside the water. Im not getting the pronunciation clear. Thank you and God bless you for the good work you are doing.
It is in the description my friend.
Could you tell me please effectiveness of the filters, does it leave any bad smells when the gas is burning
If the filters are working correctly, they are designed to remove H2S. This smells like eggs when on its own, or will smell like matches when burnt. If you can smell either of these then it could be that the scrubbers aren't working properly or your gas is very high in H2S, which could be dangerous. Other smells might be in your gas, it will depend on what you are feeding it. It is difficult to say what it could be without a better description of the smells.
Hey, are these bubblers essential? If possible can you attach Amazon links for us to find these items?
They are not essential, you can burn the gas straight from the tank. However, the burn won't be as clean and could contain dangerous chemicals. Here are the water filter containers: www.amazon.co.uk/gp/product/B01A5LSEHE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
How often do u have to change the filters and how do u identify it's time to change
How often is a difficult question. The cat litter will become visibly saturated, so you will be able to tell when you need to change that. The iron wool will rust and degrade as it reacts with the HS2, so you will be able to tell for that as well.
Cool , so many people do it in the wrong order and the steel wool rusts out before very long
Hopefully, using this system it would be quite visible whats going on, so people might guess before too long.
Where can we buy these materials and how can we contact you for guidance
It will depend where you are in the world. I got most from Amazon.
Where did you get your materials? I saw some on Amazon that looked about the same
These are the ones: www.amazon.co.uk/gp/product/B01A5LSEHE/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
My comment, How long the Gas take before it finished and how can I refill another one m
I am sorry I don't quite understand.
Hey mate, any update on how the new scrubbers went?
They seem to be working well. I haven't checked them in the last month as I've moved away from where I installed this system. I think gas production has dropped right off now the weather has got colder as well.
Bhai jaan jo jo gas ko purify karne ke liye system Lagaya Gaya Hai Isko kitne Dinon bad change karna hai.
Totally depends on the size of your digester and the food you are using.
How many liters is your digester and storage tank?
The digester is 200ltr and the gas storage is 1 cubic metre
Can this enter cylinder
It’s been a good 5 months. Any update on how it worked?
I made a mistake (see my video on filling up the digester). I fill it too much and only put two and two together recently, so I have only produced a small amount of gas. I have emptied a bit now so I am hoping that it can work, even with dropping temps. I am not living at the same property now, but am hoping to get a video out in the New Year.
Hlo wich substance use in tha scrbber. I don't understand your language. 1 woter 2 iron 3 ?
Read the description
What is that white thing in the middle called?
Cat litter
Wht is the compound inside the middle part ? (inside 2nd waterfilter)
Cat litter, anything that will remove moisture, will work. Activated charcoal is a good alternative.
sorry, sir. just curious.. so it's fine if the gas storage is a rubber?
No problem...a rubber what? Like a rubber inner tube? That's fine
How are the scrubbers working?
Yes, working so far. I haven't produced much gas as I have not been feeding much. I have been busy working on my PhD, so it and YT has taken a back seat.
so it means if there's a bubbles then the gas is passing through and if there's no bubbles then there's no gas passing through
Yeah exactly! I love it. Well, I will love it when I start seeing bubbles. Such a simple way to see if everything is working
Hey, this work is amazine and ibwould like a direct communications with you, this work exactly is part of undergraduate project and am having challenges starting it over but time is no longer on my side. So can i get so help from you, pleeez
Hey chap, reply me. Ain't you seeing my chat? Come on, am a subscriber to your channel
Sure, drop me an email tomoffgrid@gmail.com
What is the water for?
To remove CO2
@GetMeOffGrid_ how long does water last before it needs replacing?
Nice work sir, but how do I know the amount of gas I can get from a 15liters digester and what's the level the digester is to be fed with the feestock
That will all depend on the type of feed stock, temperature, size of digester etc. Varies a lot. The best way to find out is to experiment.
Are you producing any gas yet?
It did produce some gas. However, I have moved from this property now and so cannot access as easily as I could. Since it has got cold again production has declined a lot. I think there is still some room for improvement with some of the setup but haven't had the chance to play around with it recently.
Got any results yet?
I have moved from the house and so am not sure if the system I installed it working at the moment. I am going back today to check.
I guess you don't get pressure enough, might need an air pump to push it through.
I had a good night out with three scrubbers once
I so want to do this but I'm afraid of blowing the whole neighbourhood up into the ether.
Although there is a risk with unpressurised gas like this the risk is lower than when using pressurized gas
@@GetMeOffGrid_ Ok I get you so I will give this a try and maybe I can get it all set up for this coming winter
I did some research into methane, turns out this biogas production can cause quite a bit of methane emissions. One reason is leaks, so I suggest you should really try to avoid any of those. Second, the sludge that remains can also produce quite a bit of methane after it's out of the digester, twelve times more than if you would just compost the feedstock. As I read it, this is on top of the methane captured by the gas bladder. I couldn't quickly find a solution, so I'd suggest reading into it, we need a way to deal with the sludge without causing these emissions!
Interesting. How big an issue is it? Relative to the amount of gas captured? Does this take into consideration is the digester is stirred or is left static? I'd imagine if it is stirred you could convert more digestate into methane before removing the sludge.
The difference between zealous policymakers and actual scientists, is that scientists know methane is very unstable and breaks down when exposed to the UV spectrum in natural light. A rather inconvenient fact, in light of the agricultural policies being strongarmed into place at the moment.
The difference between zealous policymakers and actual scientists, is that scientists know methane is very unstable and breaks down when exposed to the UV spectrum in natural light. A rather inconvenient fact, in light of the agricultural policies being strongarmed into place at the moment.
The difference between zealous policymakers and actual scientists, is that scientists know methane is very unstable and breaks down when exposed to the UV spectrum in natural light. A rather inconvenient fact, in light of the agricultural policies being strongarmed into place at the moment.
The difference between zealous policymakers and actual scientists, is that scientists know methane is very unstable and breaks down when exposed to the UV spectrum in natural light. A rather inconvenient fact, in light of the agricultural policies being strongarmed into place at the moment.
If you're going to scrub it, why not compress it into a LPG tank too
That is the plan when it finally gets up and running and has produced enough gas
@@GetMeOffGrid_ oh I thought you had this all running already.
@@justawfulgamer7738 It has been producing gas, but I have moved out from the house and its has slowed right down in production. I haven't been able to get back over and troubleshoot the issues. From what I have been told it seems like it has been overfilled.
@@GetMeOffGrid_ please keep us posted. I'd like to do the same thing with an IBC tote. Do you have a discord or anything?
Dzień dobry
A very good one!
@@GetMeOffGrid_ 11:20 proszę dodać trochę rdzy, wejdzie szybciej w reakcję z siarkowodorem, kawałek miedzianego drutu z czernieje przy siarkowodorze. Na wszelki wypadek można zawiesić wyżej czujnik gazowy który wykryje ulatniający się metan, spryskanie wodą z mydłem po złączach nieźle bąbelkuje przy ulatniającym się gazie.
Hello sir, I am from India. I have a startup named Baramati Ecosystems. We have developed a biogas digester with capacity to provide constant pressure throughout the use of gas. I saw your work with the scrubbers and i think they are simple but quite effective. We are definitely going to include your scrubber tech in our product. I was wondering if you could guide us through some technical stuff with the scrubbers. How can we reach you.. A email address would be helpful..
Great, that you like the scrubbers. They are not my design, though. It's a common setup for small-scale biogas digesters. I am happy to help. My email is tomoffgrid@gmail.com
I would replace the water with calcium to remove the co2. Also the water directly beside the cat litter is counter productive... For more information read en.m.wikipedia.org/wiki/Calcium_looping
Can you explain why the cat litter after the water is counter productive?
Why is calcium hydroxide better?
Ca doesn't run lower degrees
Hi nice video very informative. Question, when do you replace the filters? thanks in advance
Good question. It all depends on the volume of gas you are producing, and how much gas is going through the scrubbers. The water will stop working when it becomes saturated with CO2, this will cause it to become acidic. So you can test the water to see if the pH has dropped. The desiccant will also become saturated and this is a bit easier to see, it will become visibly moist in the scrubber container. This is a huge benefit to these scrubbers: it is easy to see this. The iron wool will degrade visibly when it reacts with the H2S, so again it will be easy to see if all the iron wool has gone black/rusty.