Before compressing our wonderful biogas, we need to flush out the old LPG or Oxygen from the tanks for safety reasons, here is a look at a way to do this.
G'day Mate, love ya work. As biogas is lighter than air can you turn the bottle upside down, (probably in a jig to hold it), leave it over night so the air settles and then hook a flex hose with a burner attached. That way you take out the air and you know when you're letting out gas when you can light your burner. I'm probably over complicating things. Happy travels!
Because there is oxygen in the tank already I would be very hesitant to have the flame going until after the oxygen elimination phase even thou it’s upside down as lighter... but I honestly don’t know I’m just going with the cautious approach. 👍
Hello fellow Aussie here. Love what you are doing. Have you weighed your cylinder after filling and if so what is the weight in kilos. Also all the haters need to calm down about the gas being released. Earth's atmosphere consists of many gasses with Nitrogen being the most prevalent at 78% and Oxygen next at 21% , add those two together and you get 99% the next is Argon at •54% the rest shares the space with Helium, Methane and water vapour.
the tank needs to be pulled down to a vacuum with an A/C evacuator. you can buy them cheap at harbor freight the run off a air compressor and vacuum is created in a venturi. great video.. keep safe mate
OK this blows my mind that you can compressor with a garden hose and a compressor that would be from any hardware store. It looks like and that it doesn’t overheat
Turn down your VOLUME at 6 minute mark!! I think I just lost some hearing!! LOL!! Fantastic Video!! Thank you so much!! Getting ready to do my own build!
Good video. experiment with biogas to But I'm worried about one thing and that's crank air. If the piston moves downwards and sucks in gas through the intake, but also through leakage past the piston rings from the crankcase !! If you use a worn compressor where the leakage is large, a lot of air can leak past. I think a warning to people before something happens is good! To avoid this, I think an overpressure on the intake is a must and certainly not a small supply line that increases the vacuum. Maybe look at real biogas compressors how they work. Thanks!!
I wonder if turning the gas bottle upside down when venting. Air is heavier than methane and should all come out maybe with 1 session of venting. So even twice, it probably would eliminate all air a little better?
brilliant video, super informative with my research into biogas production! one question: when you release the gas from the tank to de-oxygenate, how can you be sure you are releasing oxygen? methane is lighter than air/oxygen so surely methan sits on top? if you were to invert the tank before de-gassing, wouldnt you in theory be forcing oxgen to the bottom of the tank and out of the valve at this point? am i missing something? anyway, great video and thatnks for the inspiration!5
Good day I love your work and appreciate your time sharing your experience, I'd like to give you an idea; what if we take out the cylinder valve and let the gas flow inside the gas cylinder for 5 minutes, I think it will be completely filled with the new gas then fixing the valve back
The density of methane at NTP is 0.668 kg/m³. The density of air at NTP is 1.204 kg/m³. The air is ~1.8 times heavier than the methane, so it sits below the methane in the tank. Your purging method is not venting the air out of the tank--it is actually venting the methane out of the tank--because the methane is at the top of the tank & the air is below it. To properly purge the air from the tank, do the following: 1. Invert the tank so that the valve is lower than the bottom of the tank. 2. Allow some time for the air to settle to the value end of the tank. 3. Open the valve to purge the air from the tank. 4. Close the valve after the air has been purged. To know when the air has been purged from the tank, you could attach a small diameter tube that is ~1 ft in length to the valve opening & then use a lighter flame to see when the output of the tube ignites. The air won't ignite, but the methane will ignite, so that is how you will know when there is no more air in the tank.
Hey Dan, Have you heard of anyone in Australia getting an EPA exemption for septic, by using composting toilets into a biogas system, like the HomeBioGas offering? Currently planning a move out to the Vic High Country, and trying to work out my options.
I'm sure this has been asked before but i'm new to your channel (love it by the way) but could you somehow run a stim to the bottom (like a keg) from a newly created and threaded hole and fill with water and as the gas fills it will force the water out the stem running to the bottom of the tank? Just a thought. Might require too much altering to the tank for the amount of times this process is required???
Love what you are doing!! Im wondering how much gas do you make a month? Estimated production? How long does the gas hold in storage, in a bag or bottle??
Great effort pretty work, now my question is what's the weight of biogas in a 12.5kg propane cylinder bottle. Is it the same weight in KG or biogas is more denser.
I love your videos. I am working on biogas plant as well but need to measure the volume of biogas produced, I am using a tyre tube as my storage. How can I measure the volume of biogas production?
Espectaculares ideas !! Que pena no poder escucharte en castellano ya q yo no se inglés. Pero prestando mucha atención se puede entender bastante bien . Una pregunta tonta . ¿ sería posible vaciar el aire del contenedor con el compresor ? Es decir en vez de usarlo para introducir gas metano ,invertirlo para quitar todo el aire del contenedor y lograr el vacío?
interesting ... just a question ... is there any reason you do not hook up a vacuum pump and pump out the cyclinder ? if the cyclinder was at 1/2 volume say at 7 psi would that save you having to vent ?
Me & my son made our first experimental biodigester at the weekend with cow manure, & the gas will be collected in a balloon & burnt off via a connected gun from a fence sprayer...I So thanks for the videos. I just wondered how much gas you collected on average...how often could you fill one of those small or large propane tanks? Thanks
Prior to when you connected the green hose to the storage bag, it was open to atmosphere. Isn't there oxygen in the green hose which you are connecting to the suction side of the compressor. Would it then be a good idea, prior to hooking discharge line from compressor to the lp tank, to first run it open to atmosphere for a couple of seconds?
thanks for all the great info mate. Good luck with the move! Looking forward to see what you do next! Perhaps you could take a couple of 20L containers of digestate liquid to kickstart the reactors when you set them up again up north? might be too gross to pack in with everything else though! In terms of bleeding the air out of the cylinders- do you do that every time? If you didn't let the tank get 100% empty, could you just fill it up again without having to do the refill/flush cycle? or are there contaminants I'm not aware of? And is methan heavier than oxygen, thus pushing the oxygen out or is it a percentage thing- each flush kicks out a percentage of oxygen down to a negligible level?
I don’t do this when using with appliances, typically air does not flow back in, and like I said biogas is very forgiving with air to fuel ratio anyway. People often ask about flash back arrestors too, but from what i have read it’s only needed for oxyacetylene.
Just a thought (fyi): for a mixture of any gaseous fuel and oxygen to be flammable (much less explosive) it needs to be in stoichiometric proportions. Even if the contents of the cylinder were somehow raised to flashpoint (bloody unlikely!), the small quantity of air (much less oxygen) remaining in the cylinder compared to the compressed biogas would NOT be explosive, or even noticeable when in use. My vote: don't waste your precious biogas! There is NO existential danger to you from the "oxygen" remaining in the cylinder. Additionally, if you have drained your cylinder of bigas (OR of LPG, come to that) to the point that it won't work in a cooker or heater, the contents of the cylinder is STILL going to be methane at atmospheric pressure, because air never entered at any point in its working life! Regarding the Loctite - try using yellow gas-proof Teflon/PTFE, then try the soapy-water test. I find that no gas gets past it, even screwed with moderate force, and it is never corroded by the gas itself. That way, you don't have to consider any of your plumbing "permanent" until you want it to be so. PS: Note this guy's experiments. You'll come to the conclusion that there is ZERO danger from any air left in the tank! czcams.com/video/NYTFQ6wvR9w/video.html
I have wondered what industry uses to compress biogass in countries where biogas is big. I always imagined high temp super hard plastic pistons that can never produce a spark even if the compressor shits its self. A freind transferred natural gass from a large house bottle using a very small tyre compressor .
Hi Daniel, hope all is good with you, I have a question if you have a minute? I have a heated and we’ll insulated 55gl drum digester. I have set the controller to 35c but the sensor is reading 48 and climbing. Should i cool it down or leave it till it gets to 55-60? And if it still wants to climb should I take the insulation off? Can they get too hot, should I rebuild it with a coolant coil, I have to say I didn’t see this coming! Anyway take care dood and thanks for the films!
Hey mate, thanks for all the kind words, I’ve been flat chat working. Make sure it does t get too hot, I’d rekon you would cook the good bacteria, think body temp, I would try at keep at 40C if I could 👍 all the best
@@danieltaurins86 thanks daniel, super excited to read your reply. I'm hoping its a sensor anomaly . going to try the fridge compressor into an leg bottle tonight! keep smiling and thanks again for all the info. big up the backyard biogasers!
@@danieltaurins86 hi Daniel, hope you’re good? Can I ask how you measure gas production and how much digester capacity you need per person to cope with gas requirements and available feedstock. There is a growing interest here in the uk for domestic digesters but generally not a lot of space so I am trying to work out the best compromise between space, waste flow in, gas flow out and running costs and practicability. In your opinion could a 200lt system ever eat all food scraps and poo from a family of four whilst at the same time replacing enough of the mains gas to make it worth the hassle? I have heard that a well running digester should produce its own volume of gas in 24 hrs, do you think this is true? If so will 200lt of uncompressed biogas run a family cooker for a day? Also ,if you don’t mind, I have started compressing into lpg bottles with a fridge compressor which I am taking up to 150psi. When you use your bottled biogas do you use a standard log regulator and if so what do you have it set on. I have noticed that modern air gun compressors are quite cheap and go up to 300bar! That industry also sells bottles to suit. Methane liquifies at 185bar or so and thus for a couple of hundred bucks it might be possible to have vehicle compatible CNG Anyway, I’ll be putting a film up of the system soon All the best and take care Cheers Tanc
Merhaba videolarını izliyorum ve güzel olduklarını düşünüyorum👍 Sormak istediğim birşey var. Biogaz doldurmak için lpg li arabalarda kullanılan tanklar uygun mu? Ve oksijensiz bir depodan biogazı kompresör yardımı ile direkt tank a basmak herhangi bir işlem yapmadan (oksijenden arındırmak için) nasıl oluyor?
Any thoughts on splitting your raw biogas output and redirecting +/- 20% back into the bottom of the digester? I'm setting up a tower digester with a CH4 aerator in the bottom to help with the agitation of the substrate while increasing efficiency... It's also reasonable to increase the CO2 scrubber effectiveness by as much as 50% by recycling chilled H2O. Lastly, I'm installing intermittent H2O absorbers to increase CH4 output concentration. 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).
No, to turn it into a liquid you would need to cool it to nearly -100 celcius, and compress it to nearly 700psi. Then store it in a cryo tank rated for 3600psi. That's not practical on a homestead. You can, however, store it compressed around 150-200psi to save space since the bladders are huge. It will give you about a 10-13x space savings to store it in a compressed cylinder.
Isn't methane(biogas) is lighter than normal air? So if we compressed biogas into the cylinder, the methane will be at the top of cylinder. So if we open the valve, wont the methane goes out instead of oxygen?
Daniel, Hi! Just getting started in the biogas world. I found your videos quite helpful. Here, in the states, there are two usual sources of gas - LPG (propane) and natural gas (which is mostly methane). I've converted a five burner stove and a clothes dryer from natural gas to propane by changing the orifice(s). I haven't heard whether you've changed orifices (jets) on any devices in which you're burning the biogas. I would think you'd need to use natural gas jets. Any thoughts or suggestions?
Howdy all y'all. New here to biogas. I've recently been looking into using biogas personally. Question I have is, do I need to do any special flushing of recently used LP tanks before filling with biogas? And/Or Does lp fumes and biogas mix without any problems? Thank you in advance for any and all help and information.
I realized you asked 6 months ago, so you may have found the answer by now. Natural gas is about 90% methane, and the rest is mostly propane, butate, and ethane. I wouldn't expect it to be any more dangerous, however you should note that propane is aboug 4x heaving than methane(scrubbed biogas), so any propane fumes in the tank will sink to the bottom, and may never actually get burned off during normal operation. You can flip the tank over, let it settle for a few hours, then open the valve to bleed it out if it's that important to you for the tank to be 100% biogas. However, think about it another way. Methane is lighter than air, so when the tank is empty, unless you turn it off immediately, the methane will slowly rise out and be replaced with the denser air. If you were to leave the tank with some propane fumes in it, when it's empty that just means pressure has equalized with the atmostphere. The propane is heavier than air, so the propane will not float out, but will stay settled in the tank. By keeping the propane fumes in the tank, you can pretty much rest assured that very little air will ever end up in the tank since it will be displaced by the propane.
@@r00ben no worries on time my friend. thank you for the valuable information. I had gotten sidetracked and t-boned by life and hadn't been able to do anything more with this. Once I get all this modern day world crap taken care of, I'll be able to get back to the biogas project. Another curiosity I have is, will biogas condense into a liquid safely by running it through a chilled condenser using an old window unit compressor and condensing coil? If so, then that will be sending me down another road of sustainability.
@@Sport--willow I looked into this recently. You can find videos on YT of people "liquifying biogas", but they never actually show/prove it was liquified. What I learned in my research is that it takes a TON of energy to liquify methane. You can google specifics, but basically, you compress it to 700psi and cool it to -100 degrees celcius, then store it in a cryo tank rated at 3000-3600psi. You'd probably be better off installing a 120 gallon propane tank on your property, and using a high pressure pump (such as AC or refrigerator compressor) to fill it to about 330-350 psi. At 390 PSI it would hold approximately 430k BTUs, which is the same as a small 20lb tank full of propane. Propane tanks are expected to fluctuate between 150-350 psi, but they're built and pressure tested to 600 psi. So while you could probably go higher than 330-350, I'd prefer to stay on the safe side.
I haven't done this, and am not necessarily reccomending this. This is for informational purposes. You can find portable 100lb propane tanks w/ wheels and a handle, online for about $75. If you filled one of those tanks to 430 psi, it would be the BTU equavalent to 1 gallon of propane. A 20lb propane tank is usually filled to about 3.9 gallons (they leave room for gas expansion). So 4 portable 100lb tanks on wheels would be relatively convenient, and would hold a decent amount of fuel. One of those tanks would probably run a small Honda 2200 inverter generator for 6-8 hours. Given the higher than usual pressures, I'd store them somewhere that doesn't get insanely hot, definately not in direct sunlight, like maybe in a venilated garage or toolshed
I think you'd actually want to turn the bottle upside down, let the air settle at the bottom for a few hours, then vent it, otherwise you're likely just venting methane, or a methane/air mixture. If you flip the bottle and let the air settle, you're venting pure air, which if left in the tank would create condensation which could rust the tank.
Propane tanks are designed to handle a large pressure range due to the fact that propane expands and contracts based on the temperature. This range is usually between 150psi to 200psi, however in extreme temperatures it can reach up to 350 psi. Tanks are built and pressure tested to withstand about double that for safety purposes. When you're looking for air compressors at the hardware store, they usually don't go much higher than 200psi. You should be able to safely store methane at 200psi in a propane tank. Methane could tolerate higher compression, but you would have to find a tank and compressor reated for those pressures as well. Industrial methane/natural gas tanks are cryo tanks, usually rated between 3000-3600 psi, and they hold the liquid methane around -100 celcius. In it's liquid state, you'd have a compression ratio of 593:1 (compared to 13.7:1 at 200psi), but achieving and maintaing those temperatures is not really practical or feasible in a home setting.
@@r00ben Thanks for the info. Where did you get your numbers if you don't mind me asking. I have searched online and can't get anything close to what you wrote.
@@w4447 I just used math. For example at 390psi, the compression rate is 390/14.7 = 26.5. A 120 US Gallon propane tank would hold a compressed volume of 120 * 26.5 = 3180 gallons. 3180 US Gallons = 425 cubic feet. Methane has a BTU rating of 1010 BTU per cu ft. 425 x 1010 = 429,250 BTU, which is just shy of the 430,000 BTU in a 20lb tank of propane filled 100% (which it never is). For safety purposes they usually only fill them to 80%, which is actually 93000 BTU * 3.9 Gallon = 362,700 BTU. If you wanted to find out the compression ratio to use to store 363k BTU worth of methane in a given tank you would do the math in reverse like this: 363000/1010 = 359.4 cu ft 359.4 cu ft * 7.48 = 2688 US Gallons 2688 US Gallons / 120 gal = 22.4x compression rate 22.4 * 14.7 psi (1 bar) = 329 PSI Therefore a 120 Gallon propane tank, filled with methane at 330 PSI would hold the equivalent BTUs of a propane tank you'd buy off the shelf filled with 3.9 gallons of propane. Hope that helps. If you find a mistake in my math, please let me know.
@@w4447 Also, when calculating for methane, you can take into account the entire cylinder volume (the WC/water capacity) since it's a gas and not a liquid. Liquid Propane is typically only filled to 80%, but compressed methane gas will fill 100% of the container. When you look up the volumes for different containers, sometimes the source may report the liquid volume capacity, rather than the total capacity, so it varies. Also if you use google for volume conversions, make sure you're the correct "gallons" (or whatever value) each time. I noticed that sometimes it will use US Fluid Gallon, and sometimes it will use Imperial Gallon, which are NOT the same, so keep an eye out for that.
@@w4447 Also, just remembered that propane tanks have a pressure relief valve to prevent the tank from exploding. I double-checked and it seems they are usually configured for about 375 psi, so you'll want to keep the PSI well below that.
It wouldn't last very long, maybe a few minutes. A generator goes through about a gallon of liquid propane in 7 hours. Liquid propane is stores at a compression ratio of 493:1. Compressed biogas is stored at a compression rate of 10-13x (it's a compressed gas, not a liquid). To put this into perspective, a 20lb propane tank holds about 430k BTU of energy. That same tank, filled with compressed biogas at 200psi would only hold about 8k BTU. You would need 54 tanks, or one of the large 250 gallon propane tanks to equal the amount of energy in a small 20lb propane tank. Another way to think of it... have you seen the tall propane tanks on the back of food trucks? Those are 100lb tanks, which old about 20 gallons, so imagine 12 of those filled with biogas-- that's about the same amount of energy you'd get from one small tank filled with propane. Could you run a generator from biofuel, sure you can... it's just not very practical.
Anyone else intrigued by the irony of the dart board in the background right next to a giant balloon holding flammable gas?😂 Gave me a good chuckle
G'day Mate, love ya work. As biogas is lighter than air can you turn the bottle upside down, (probably in a jig to hold it), leave it over night so the air settles and then hook a flex hose with a burner attached. That way you take out the air and you know when you're letting out gas when you can light your burner. I'm probably over complicating things. Happy travels!
Because there is oxygen in the tank already I would be very hesitant to have the flame going until after the oxygen elimination phase even thou it’s upside down as lighter... but I honestly don’t know I’m just going with the cautious approach. 👍
Are you thinking that would be more dangerous? I don't know anything about gases
Whats ur Facebook account sir im asking for how to compress biogas
🥩 Excellent advice, solid scientific base, practical solution!! 👏🏾👏🏾👏🏾👏🏾👏🏾👏🏾 🥩
I was thinking the exact same thing while watching this video.
Hi Thanks for video, Try a fridge compress, slower but higher PSI use a one way valve in line,
You are my go to guy for everything biogas. Love your channel and hope you keep making videos after your move. Good luck !
Hello fellow Aussie here. Love what you are doing. Have you weighed your cylinder after filling and if so what is the weight in kilos. Also all the haters need to calm down about the gas being released. Earth's atmosphere consists of many gasses with Nitrogen being the most prevalent at 78% and Oxygen next at 21% , add those two together and you get 99% the next is Argon at •54% the rest shares the space with Helium, Methane and water vapour.
the tank needs to be pulled down to a vacuum with an A/C evacuator. you can buy them cheap at harbor freight the run off a air compressor and vacuum is created in a venturi. great video.. keep safe mate
OK this blows my mind that you can compressor with a garden hose and a compressor that would be from any hardware store. It looks like and that it doesn’t overheat
Turn down your VOLUME at 6 minute mark!! I think I just lost some hearing!! LOL!! Fantastic Video!! Thank you so much!! Getting ready to do my own build!
Best of luck with the move bro.
A few months off yet, painting the house and packing up, would be good to catch up for a pub lunch or something with you guys soon !
Good video. experiment with biogas to But I'm worried about one thing and that's crank air.
If the piston moves downwards and sucks in gas through the intake, but also through leakage past the piston rings from the crankcase !! If you use a worn compressor where the leakage is large, a lot of air can leak past. I think a warning to people before something happens is good!
To avoid this, I think an overpressure on the intake is a must and certainly not a small supply line that increases the vacuum. Maybe look at real biogas compressors how they work.
Thanks!!
I wonder if turning the gas bottle upside down when venting. Air is heavier than methane and should all come out maybe with 1 session of venting. So even twice, it probably would eliminate all air a little better?
Yes that would work
Also add a check valve near the tank fitting and run the compressor for a few seconds before hooking it up to the tank to purge the lines of air
brilliant video, super informative with my research into biogas production!
one question: when you release the gas from the tank to de-oxygenate, how can you be sure you are releasing oxygen? methane is lighter than air/oxygen so surely methan sits on top?
if you were to invert the tank before de-gassing, wouldnt you in theory be forcing oxgen to the bottom of the tank and out of the valve at this point? am i missing something?
anyway, great video and thatnks for the inspiration!5
Good day I love your work and appreciate your time sharing your experience, I'd like to give you an idea; what if we take out the cylinder valve and let the gas flow inside the gas cylinder for 5 minutes, I think it will be completely filled with the new gas then fixing the valve back
The density of methane at NTP is 0.668 kg/m³.
The density of air at NTP is 1.204 kg/m³.
The air is ~1.8 times heavier than the methane, so it sits below the methane in the tank.
Your purging method is not venting the air out of the tank--it is actually venting the methane out of the tank--because the methane is at the top of the tank & the air is below it.
To properly purge the air from the tank, do the following:
1. Invert the tank so that the valve is lower than the bottom of the tank.
2. Allow some time for the air to settle to the value end of the tank.
3. Open the valve to purge the air from the tank.
4. Close the valve after the air has been purged.
To know when the air has been purged from the tank, you could attach a small diameter tube that is ~1 ft in length to the valve opening & then use a lighter flame to see when the output of the tube ignites. The air won't ignite, but the methane will ignite, so that is how you will know when there is no more air in the tank.
Hey Dan,
Have you heard of anyone in Australia getting an EPA exemption for septic, by using composting toilets into a biogas system, like the HomeBioGas offering? Currently planning a move out to the Vic High Country, and trying to work out my options.
Great video, would you be able to fit a T-piece from your bag.. Save some wear and tear on the connection.
And hope your move goes smoothly
isnt there a screw diver valve at the top where you fill the tank to let the air out?
I'm sure this has been asked before but i'm new to your channel (love it by the way) but could you somehow run a stim to the bottom (like a keg) from a newly created and threaded hole and fill with water and as the gas fills it will force the water out the stem running to the bottom of the tank? Just a thought. Might require too much altering to the tank for the amount of times this process is required???
I'm going into summer now, My digester is now starting to crank, I've already ran my gas generator on biogas this year.
Love what you are doing!! Im wondering how much gas do you make a month? Estimated production? How long does the gas hold in storage, in a bag or bottle??
Great effort pretty work, now my question is what's the weight of biogas in a 12.5kg propane cylinder bottle. Is it the same weight in KG or biogas is more denser.
What is the comparison of usage time on how long those tanks last compared to propane?
I love your videos.
I am working on biogas plant as well but need to measure the volume of biogas produced, I am using a tyre tube as my storage.
How can I measure the volume of biogas production?
Espectaculares ideas !! Que pena no poder escucharte en castellano ya q yo no se inglés. Pero prestando mucha atención se puede entender bastante bien . Una pregunta tonta . ¿ sería posible vaciar el aire del contenedor con el compresor ? Es decir en vez de usarlo para introducir gas metano ,invertirlo para quitar todo el aire del contenedor y lograr el vacío?
Air is heavier than methane, you should gas that cylinder upside down.
interesting ... just a question ... is there any reason you do not hook up a vacuum pump and pump out the cyclinder ? if the cyclinder was at 1/2 volume say at 7 psi would that save you having to vent ?
Me & my son made our first experimental biodigester at the weekend with cow manure, & the gas will be collected in a balloon & burnt off via a connected gun from a fence sprayer...I
So thanks for the videos. I just wondered how much gas you collected on average...how often could you fill one of those small or large propane tanks? Thanks
Prior to when you connected the green hose to the storage bag, it was open to atmosphere. Isn't there oxygen in the green hose which you are connecting to the suction side of the compressor. Would it then be a good idea, prior to hooking discharge line from compressor to the lp tank, to first run it open to atmosphere for a couple of seconds?
thanks for all the great info mate. Good luck with the move! Looking forward to see what you do next! Perhaps you could take a couple of 20L containers of digestate liquid to kickstart the reactors when you set them up again up north? might be too gross to pack in with everything else though! In terms of bleeding the air out of the cylinders- do you do that every time? If you didn't let the tank get 100% empty, could you just fill it up again without having to do the refill/flush cycle? or are there contaminants I'm not aware of? And is methan heavier than oxygen, thus pushing the oxygen out or is it a percentage thing- each flush kicks out a percentage of oxygen down to a negligible level?
I don’t do this when using with appliances, typically air does not flow back in, and like I said biogas is very forgiving with air to fuel ratio anyway. People often ask about flash back arrestors too, but from what i have read it’s only needed for oxyacetylene.
Just a thought (fyi): for a mixture of any gaseous fuel and oxygen to be flammable (much less explosive) it needs to be in stoichiometric proportions.
Even if the contents of the cylinder were somehow raised to flashpoint (bloody unlikely!), the small quantity of air (much less oxygen) remaining in the cylinder compared to the compressed biogas would NOT be explosive, or even noticeable when in use.
My vote: don't waste your precious biogas!
There is NO existential danger to you from the "oxygen" remaining in the cylinder.
Additionally, if you have drained your cylinder of bigas (OR of LPG, come to that) to the point that it won't work in a cooker or heater, the contents of the cylinder is STILL going to be methane at atmospheric pressure, because air never entered at any point in its working life!
Regarding the Loctite - try using yellow gas-proof Teflon/PTFE, then try the soapy-water test.
I find that no gas gets past it, even screwed with moderate force, and it is never corroded by the gas itself.
That way, you don't have to consider any of your plumbing "permanent" until you want it to be so.
PS: Note this guy's experiments. You'll come to the conclusion that there is ZERO danger from any air left in the tank!
czcams.com/video/NYTFQ6wvR9w/video.html
How long does the bbq bottle run the heater?
How's the digesters doing?
Vari good
I have wondered what industry uses to compress biogass in countries where biogas is big. I always imagined high temp super hard plastic pistons that can never produce a spark even if the compressor shits its self. A freind transferred natural gass from a large house bottle using a very small tyre compressor .
A viewer from the UK said a plant there sells the CO2 back to soft drink companies to carbonate their products...... I have never thought of that.
Podría utilizarse un compresor de frigorífico?
How long does the bottle last
Hi Daniel, hope all is good with you, I have a question if you have a minute? I have a heated and we’ll insulated 55gl drum digester. I have set the controller to 35c but the sensor is reading 48 and climbing. Should i cool it down or leave it till it gets to 55-60? And if it still wants to climb should I take the insulation off? Can they get too hot, should I rebuild it with a coolant coil, I have to say I didn’t see this coming! Anyway take care dood and thanks for the films!
Hey mate, thanks for all the kind words, I’ve been flat chat working. Make sure it does t get too hot, I’d rekon you would cook the good bacteria, think body temp, I would try at keep at 40C if I could 👍 all the best
@@danieltaurins86 thanks daniel, super excited to read your reply. I'm hoping its a sensor anomaly . going to try the fridge compressor into an leg bottle tonight! keep smiling and thanks again for all the info. big up the backyard biogasers!
@@danieltaurins86 hi Daniel, hope you’re good? Can I ask how you measure gas production and how much digester capacity you need per person to cope with gas requirements and available feedstock. There is a growing interest here in the uk for domestic digesters but generally not a lot of space so I am trying to work out the best compromise between space, waste flow in, gas flow out and running costs and practicability. In your opinion could a 200lt system ever eat all food scraps and poo from a family of four whilst at the same time replacing enough of the mains gas to make it worth the hassle? I have heard that a well running digester should produce its own volume of gas in 24 hrs, do you think this is true? If so will 200lt of uncompressed biogas run a family cooker for a day? Also ,if you don’t mind, I have started compressing into lpg bottles with a fridge compressor which I am taking up to 150psi. When you use your bottled biogas do you use a standard log regulator and if so what do you have it set on.
I have noticed that modern air gun compressors are quite cheap and go up to 300bar! That industry also sells bottles to suit. Methane liquifies at 185bar or so and thus for a couple of hundred bucks it might be possible to have vehicle compatible CNG
Anyway, I’ll be putting a film up of the system soon
All the best and take care
Cheers
Tanc
Merhaba videolarını izliyorum ve güzel olduklarını düşünüyorum👍
Sormak istediğim birşey var. Biogaz doldurmak için lpg li arabalarda kullanılan tanklar uygun mu? Ve oksijensiz bir depodan biogazı kompresör yardımı ile direkt tank a basmak herhangi bir işlem yapmadan (oksijenden arındırmak için) nasıl oluyor?
Any thoughts on splitting your raw biogas output and redirecting +/- 20% back into the bottom of the digester? I'm setting up a tower digester with a CH4 aerator in the bottom to help with the agitation of the substrate while increasing efficiency...
It's also reasonable to increase the CO2 scrubber effectiveness by as much as 50% by recycling chilled H2O.
Lastly, I'm installing intermittent H2O absorbers to increase CH4 output concentration.
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).
I just wonder how much run time you get from each full tank of biogas? And the size of the wattage/amperage of your generator! Nice!
I did a vid of it running through a 2kw gen, was about an hour for memory
@@danieltaurins86 watching... a year later! LOL!! Nothing like not receiving "notifications"!
Hi a very interesting video q does your bio gas actually turn into liquid.
Kind regards and keep up the brilliant work.
No, to turn it into a liquid you would need to cool it to nearly -100 celcius, and compress it to nearly 700psi. Then store it in a cryo tank rated for 3600psi. That's not practical on a homestead. You can, however, store it compressed around 150-200psi to save space since the bladders are huge. It will give you about a 10-13x space savings to store it in a compressed cylinder.
Isn't methane(biogas) is lighter than normal air? So if we compressed biogas into the cylinder, the methane will be at the top of cylinder. So if we open the valve, wont the methane goes out instead of oxygen?
Why? It all burns fine.
Would the air be lighter than the gas...and therefore collect at the top of the cylinder?
that would be my question also...
Pretty sure Methane is lighter than air
De todos modos se podría vaciar la botella de aire con el compresor creo supongo
The opposite.
How about using an old fridge compressor to create a vacuume?
Very possible, has been done👍
Bro just use a vacuum pump. Hook up the fitting, open the valve vac it down, close the valve while under vac, disconnect. bingo boingo
Daniel, Hi! Just getting started in the biogas world. I found your videos quite helpful. Here, in the states, there are two usual sources of gas - LPG (propane) and natural gas (which is mostly methane). I've converted a five burner stove and a clothes dryer from natural gas to propane by changing the orifice(s). I haven't heard whether you've changed orifices (jets) on any devices in which you're burning the biogas. I would think you'd need to use natural gas jets. Any thoughts or suggestions?
Hi Brian, yes the smaller LPG jets are too small for biogas, I just drill them to make them bigger 👍
METHANE IS LIGHTER THAN AIR ,,SO THE AIR IS AT THE BOTTOM OF THE TANK ,,YOU ARE RELEASING THE METHANE NOT THE AIR
Howdy all y'all. New here to biogas.
I've recently been looking into using biogas personally.
Question I have is, do I need to do any special flushing of recently used LP tanks before filling with biogas?
And/Or
Does lp fumes and biogas mix without any problems?
Thank you in advance for any and all help and information.
I realized you asked 6 months ago, so you may have found the answer by now. Natural gas is about 90% methane, and the rest is mostly propane, butate, and ethane. I wouldn't expect it to be any more dangerous, however you should note that propane is aboug 4x heaving than methane(scrubbed biogas), so any propane fumes in the tank will sink to the bottom, and may never actually get burned off during normal operation. You can flip the tank over, let it settle for a few hours, then open the valve to bleed it out if it's that important to you for the tank to be 100% biogas. However, think about it another way. Methane is lighter than air, so when the tank is empty, unless you turn it off immediately, the methane will slowly rise out and be replaced with the denser air. If you were to leave the tank with some propane fumes in it, when it's empty that just means pressure has equalized with the atmostphere. The propane is heavier than air, so the propane will not float out, but will stay settled in the tank. By keeping the propane fumes in the tank, you can pretty much rest assured that very little air will ever end up in the tank since it will be displaced by the propane.
@@r00ben no worries on time my friend. thank you for the valuable information. I had gotten sidetracked and t-boned by life and hadn't been able to do anything more with this. Once I get all this modern day world crap taken care of, I'll be able to get back to the biogas project.
Another curiosity I have is, will biogas condense into a liquid safely by running it through a chilled condenser using an old window unit compressor and condensing coil?
If so, then that will be sending me down another road of sustainability.
@@Sport--willow I looked into this recently. You can find videos on YT of people "liquifying biogas", but they never actually show/prove it was liquified. What I learned in my research is that it takes a TON of energy to liquify methane. You can google specifics, but basically, you compress it to 700psi and cool it to -100 degrees celcius, then store it in a cryo tank rated at 3000-3600psi.
You'd probably be better off installing a 120 gallon propane tank on your property, and using a high pressure pump (such as AC or refrigerator compressor) to fill it to about 330-350 psi. At 390 PSI it would hold approximately 430k BTUs, which is the same as a small 20lb tank full of propane. Propane tanks are expected to fluctuate between 150-350 psi, but they're built and pressure tested to 600 psi. So while you could probably go higher than 330-350, I'd prefer to stay on the safe side.
I haven't done this, and am not necessarily reccomending this. This is for informational purposes. You can find portable 100lb propane tanks w/ wheels and a handle, online for about $75. If you filled one of those tanks to 430 psi, it would be the BTU equavalent to 1 gallon of propane. A 20lb propane tank is usually filled to about 3.9 gallons (they leave room for gas expansion). So 4 portable 100lb tanks on wheels would be relatively convenient, and would hold a decent amount of fuel. One of those tanks would probably run a small Honda 2200 inverter generator for 6-8 hours. Given the higher than usual pressures, I'd store them somewhere that doesn't get insanely hot, definately not in direct sunlight, like maybe in a venilated garage or toolshed
sir gd mrng from philipine can i as you can u how can liquify biogas can i teach me pls.
Hi, I'm having trouble getting my gas bottle can you please help me
How much biogas does it take to fill up a 20lb tank?
It would hold about 240 liters of biogas
Why and how does venting the bottle as you fill it, release the oxygen?
I think you'd actually want to turn the bottle upside down, let the air settle at the bottom for a few hours, then vent it, otherwise you're likely just venting methane, or a methane/air mixture. If you flip the bottle and let the air settle, you're venting pure air, which if left in the tank would create condensation which could rust the tank.
@@r00ben makes sense.. thanks 👍
If You put the gastank in a freezer the gas wil be liquid . the pressure in the cylinder would also be very low.
Does your freezer get to -100 celcius? You need extremely cold temps, and very high pressure (nearly 700psi) to liquify methane.
What do you think the max pressure you can compress methane at is?
Propane tanks are designed to handle a large pressure range due to the fact that propane expands and contracts based on the temperature. This range is usually between 150psi to 200psi, however in extreme temperatures it can reach up to 350 psi. Tanks are built and pressure tested to withstand about double that for safety purposes. When you're looking for air compressors at the hardware store, they usually don't go much higher than 200psi. You should be able to safely store methane at 200psi in a propane tank. Methane could tolerate higher compression, but you would have to find a tank and compressor reated for those pressures as well. Industrial methane/natural gas tanks are cryo tanks, usually rated between 3000-3600 psi, and they hold the liquid methane around -100 celcius. In it's liquid state, you'd have a compression ratio of 593:1 (compared to 13.7:1 at 200psi), but achieving and maintaing those temperatures is not really practical or feasible in a home setting.
@@r00ben Thanks for the info. Where did you get your numbers if you don't mind me asking. I have searched online and can't get anything close to what you wrote.
@@w4447 I just used math. For example at 390psi, the compression rate is 390/14.7 = 26.5. A 120 US Gallon propane tank would hold a compressed volume of 120 * 26.5 = 3180 gallons. 3180 US Gallons = 425 cubic feet. Methane has a BTU rating of 1010 BTU per cu ft. 425 x 1010 = 429,250 BTU, which is just shy of the 430,000 BTU in a 20lb tank of propane filled 100% (which it never is). For safety purposes they usually only fill them to 80%, which is actually 93000 BTU * 3.9 Gallon = 362,700 BTU.
If you wanted to find out the compression ratio to use to store 363k BTU worth of methane in a given tank you would do the math in reverse like this:
363000/1010 = 359.4 cu ft
359.4 cu ft * 7.48 = 2688 US Gallons
2688 US Gallons / 120 gal = 22.4x compression rate
22.4 * 14.7 psi (1 bar) = 329 PSI
Therefore a 120 Gallon propane tank, filled with methane at 330 PSI would hold the equivalent BTUs of a propane tank you'd buy off the shelf filled with 3.9 gallons of propane.
Hope that helps. If you find a mistake in my math, please let me know.
@@w4447 Also, when calculating for methane, you can take into account the entire cylinder volume (the WC/water capacity) since it's a gas and not a liquid. Liquid Propane is typically only filled to 80%, but compressed methane gas will fill 100% of the container. When you look up the volumes for different containers, sometimes the source may report the liquid volume capacity, rather than the total capacity, so it varies. Also if you use google for volume conversions, make sure you're the correct "gallons" (or whatever value) each time. I noticed that sometimes it will use US Fluid Gallon, and sometimes it will use Imperial Gallon, which are NOT the same, so keep an eye out for that.
@@w4447 Also, just remembered that propane tanks have a pressure relief valve to prevent the tank from exploding. I double-checked and it seems they are usually configured for about 375 psi, so you'll want to keep the PSI well below that.
Ever thought of using compressed biogas to fuel your home generator?
It wouldn't last very long, maybe a few minutes. A generator goes through about a gallon of liquid propane in 7 hours. Liquid propane is stores at a compression ratio of 493:1. Compressed biogas is stored at a compression rate of 10-13x (it's a compressed gas, not a liquid). To put this into perspective, a 20lb propane tank holds about 430k BTU of energy. That same tank, filled with compressed biogas at 200psi would only hold about 8k BTU. You would need 54 tanks, or one of the large 250 gallon propane tanks to equal the amount of energy in a small 20lb propane tank. Another way to think of it... have you seen the tall propane tanks on the back of food trucks? Those are 100lb tanks, which old about 20 gallons, so imagine 12 of those filled with biogas-- that's about the same amount of energy you'd get from one small tank filled with propane. Could you run a generator from biofuel, sure you can... it's just not very practical.
Why not just use an air conditioning vacuum pump?
Dzień dobry.
Your борода can be exposed from sparks haa
The next step has to be to buy a old au on gas and see if she'll run.
AU falcon that is
Good idea.we have such kind of project , kindly help