Best way to Load a Small Scale Anaerobic Digester?
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- Опубликовано: 2 окт 2024
- Anaerobic digester are great solutions for off-grid living and ranchers/farmers. They produce power from organic material. But getting that organic material into the digester is the major challenge and it's one that not many people have solved.
This is the continuation of a series of videos that will start to document the challenges we face with each of the various systems. In this video we will go over the challenges we've faced with respect to loading the digester.
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Similar idea to the muffing monster is the plastic shredder from preciousplastic.com. Its all open source with videos and CAD drawings so you can make your own. After its shredded the macerator pump you have should work.
Hi @TheRealMartian Great Videos! Here's some ideas about feeding in the Straw : 1. Maybe consider not using straw as bedding and instead use something else. 2. Consider excluding the straw from the flow altogether (strain/rake it out)- Does it have much nutrition for the biodigester? I would think it mostly adds fibre and air. 3. Chop it up with a machine while still "dry"prior to adding it to the slurry, there are a few machines for this I think called "hammer mills. 4. Some sort of "combine harvester"type device at the top of the tank that sort of rakes and chops it while it floats. Anyway, best of luck!
Try an impeller ., not a propeller . Look into the impellers being used now in water towers . It create a cyclonic effect , and is really wnergy efficient .
underground conveyor belt? pipe that you load the stuff into, shut the loading panel, then run water into the pipe building up water pressure until the stuff moves and gets flushed?
Perhaps a hammer mill shredder that works the material until it goes through a screen would get the material consistent enough to pump.
A winter feeding system that eliminates the hay an straw getting mixed with the manure. We had this with our goat dairy. Each animal was tied in a stall with a wood floor and a cement gutter behind. They had to lift their had up and put it through a keyhole to get to the hay in the manger. This kept them from pulling their head out of the manger with each bite and dropping some at their feet. The back edge of the floor was slotted and extended over the gutter. We then could use a scraper to push the manure out the end of the barn. Many of them preferred to sleep on the warm wood floor over the lounging area with bedding.
Get a 55 gallon steel barrel where the lid comes off. Fill it with manure. Put the lid back on and fill with water through the small port. Let soak for 2 days. Then pour in???
Maybe it the height of the loading inlet, in Brazil they have small biodigestor in farms, and it works fine. See the example ruclips.net/video/eZfx5KV14p0/видео.html
ruclips.net/video/v3D8BP8l_L0/видео.html
Have you come up with a shredder idea, I’m working on a 7-10,000 gal digester for a output of a consistent 100,000 btu capability. Feed stock will be animal waste and forage waste, growing greens in a greenhouse is also considered to keep the digester active during the winter months.
Dear Mr. Martian, Try researching industrial mixers vs grinders or shedders. I've seen in delicatessens and other sausage making facilities these large tub grinder mixers that grind up meats and ice for sausages. If you just added enough water to your straw/horse poo as you added it to this mixer it might work. You would just have to find a way to drain it or pump out the horse poo slurry.
You haven't named the correct problem and identified your limiting factor. You have a super duper 2-foot diameter feed tube that goes down how many feet to an itsy bitsy teenie weenie 8-inch diameter pipe that goes down how many more feet until the food will clear the pipe and float up inside the digestion chamber. Your problem and the single factor that limits you is the 8-inch feed pipe into the digester chamber. There are a lot of RUclips videos of this design: Puxin biogas system from China. You might want to look them up.
Have you solved this problem yet? If not email me at rknyum@gmail.com I have a simple cost effective solution that will boggle your mind.
Very informative..thx for explaining the loading problem in detail.
You mentioned that a screw would push water\waste up a pipe but not down a pipe. What if you created a gradual upward bend at the bottom of the intake pipe that feed into a small upward screw? Gravity would create pressure and the upward screw may induce a siphon affect. I'm not an engineer, so I have nothing to base for this theory.
Does the waste in the pipe flow better when the pressure from the methane is weaker? Is there a way to siphon off the methane from the main tank into the two holding tanks, which would build more pressure in the two holding tanks but allow the main tank to have less downward pressure and allow more waste to fill the main tank?
Or maybe an above ground natural gas tank that temporally relieves pressure from the main tank by opening a valve, which might be enough to suck the waste into the main tank. Once the pressure equalizes have it shut off the valve to the main tank. Then have it slowly pump the methane into the holding tanks and then repeat the process.
Did ever think about using a new ibc tote piping the bottom of the tote to the bottom of your digester. Filling the pipe and tote with your organic material then water. Then use putting the lid back on the tote and either using methane or some other gas to push all of your material into it. I mean idk if it would work but the water that's in your gas holding tank gets forced out the bottom by the gas. The only thing I think that might be the problem is the pressure on the pipes and oxygenating your tank if you use just a regular air compressor. You could hook your methane up to a air compressor and use it that way. Do you have any updates?
Have you tried a "pusher" with a grate the size of your pipe? The grate end can push solid material down without pushing all the water. Leave it pushed in when not loading and remove it to load...
I don't know if you already looked at it or not but there is a video of a guy doing a household digester in Puerto Rico I think. The video is at ruclips.net/video/7R3Xtp5PXtc/видео.html
The digester part starts at about 27:20. Might give you some ideas.
Why does the inlet pipe need to be at 90 degrees why not 45 degrees. What comes to mind is a hydraulic cylinder, once a day retact the Pistons and rod, open a trap door up fill the cylinder up, close and send the rod and Piston back down the cylinder injecting the digester
I didn't read all comments so if this is suggested already or in the last part of the video then sorry. But a downward push with the right screw auger similar to the grain lift auger they use to lift grain will fix your problem. Needs to be as close to the size of your big inlet pipe.
well i found a solution to that but my digester is above ground, I made a cavity that is bellow the level of the digester with 2 opening that can be sealed , one for putting whaterever I want , and the other is attached to the side of the digester, I put every thing in it and I seal it ,Than I flash it with the liquid from the digester and every thing wil float back to the digester from the 2nd opening , but if you do that you should pay attention not to flash air with it buy leveling the openings and you will need a little pump to empty it afterwards.
Wel the problem would have been easyer too fix if the digester was more planed inn the beginning. But when that is said i think what you are doing is a great thing when it comes too renevable energy and food. All the best from Norway
Why not put all the materials that the pump can't handle, and put them in on the discharge side of the pump. Let the water pressure push them down.
Take a look at the shredder for recycling used tires and emulate that design, then pump that material to the tack in additional I don't see that your design have a 22 degree angle at the in let's Pipe, that seems to work for other design. How are you trying to reverse the screw motion that instead of pulling it porch.
You could shred the organic waste by hand and preproces quite a big amount.
Please get a hold of me on facebook, i ran a 6 million gallon digester for 5 years and had it running like a top. I will tell you all I did to fix it.
What to do if pig manure cannot produce gas in the digester? Hoping for your answer pls.
Loading idea - would take some testing and development but it is simple: piston in a cylinder, no pre-processing, load cylinder, push piston and force all material into digester. Like a hydraulic cylinder or caulking gun with a cover. Ideally, the piston would be on the bottom and push upward since the feed floats. Load through the top. Close the cover that seals to the cylinder. Piston pushes the floating mass through a side port at the top. Floating mass goes first since the port is at the top. Maybe a horizontal cylinder arrangement is an option.
Yeah, hydraulic power for this. There isn't really any benefit to grinding it up first, just uses energy. Pump it in with hydraulics, i see some form of V shaped hole in the ground, pumping in the material to the bottom of the tank, fill the V, run the pump back and forth a few times, not sure how to handle the backpressure etc, do they make 10" one way valves? :)
With positive displacement, piston can be on top - floating mass would not be an issue.
I agree. Use a piston pump just like a concrete pumper.
just what i thought
I might have completely the wrong idea here, but why not a vertical "piston".
Extend the 8" pipe above ground, cut a large port in the side for loading and use a heavy weighted plunger/air piston/ hand winch to push it all down and out the bottom of the tube inside.
One potential answer to the straw & food waste grinder problem is to look towards nature for help. Pigs convert virtually anything edible into a finer slurry than horses, cattle or sheep. It does mean you have to manage more animals, but pig meat has value to some people.
It worked in the Mad Max films, so it *must* be true ;)
Hope it helps.
R.
Just an idea to add to the mix - Why not use a variable pitch auger that goes in your 8” loading pipe? Have a loading hopper that you load your raw material and extract water from your digester to flush the material through. You need to drive the auger very fast and the speed will pulverise your materials as you feed in the liquid from your digester. The hopper will act as a mixing location. The auger will need to extend from the discharge end at the bottom of you digester up to the top of your hopper where your drive is located. Getting the balance of solids and liquids in your loading hopper will mitigate the tendency of your materials to float.
Xoncention thats how it is done in Germany, we have a lot of agricultural digesters here.
Back in my process engineering days in the chemical industry we used a "Fitzmill" for reducing particle size. The unit is called a comminuator in that it both shears the feed with a rotating knife and mashes it against the housing with a blunt hammer. They're used in the food industry for "grinding" cucumber for pickle relish hence the name "pickle grinder". A small unit consumes about 3Kw and will process up to 100Kg/hr. You can also feed both solids and slurries. You may have to collect the ground product in a drum or similar as I don't know if there's enough pressure generated to force product through a hose. Made by Fitzpatrick Industries and many used ones out there.
Don't tell me what doesn't work, tell me what does eork.
Love this project! You're doing an excellent job. How about a summer digester update?
For stirring: look in your bulk tank.
For preprocessing: Look at your juicer in your kitchen. And pump some of the top water before the juicer to prevent.drying.
Don't load the digester from the top but directly into the bottom.
If that doesn't work pressure makes stuff get wet. A large propane tank to pre wet all ingredients before into large digester.
***Problems solved***
Once you load the floating scraps into the loader (green lid outside you showed), have a mesh/grate pusher that you can put over top the floating stuff. Then push it down (sort of like a plunger with the same width as the hole, except it allows the water to flow up and over the scraps). As far as I know, if those various floating scraps are kept under water like that for long enough they'll sink due to soaking up water. Not sure it that's the case, but if so, should be the most simple solution. ¯\_(ツ)_/¯
Small scale. That's funny.
I don't know the electric needs of my idea but you can figure it out if it sounds like it might work....years ago I worked in a meat processing plant and we had a couple of mixer/grinders that would do exactly what your trying to do with the pre grinding and it could also pump that ground up material into the digester because we use that same machine to stuff sausage. It's the machine is made by Hobart you can get them and several sizes we had a small 100 lb capacity mixer grinder and we also had a couple of large ones and the 502 a thousand pound range and basically what it is is just like your your home hamburger grinder but on an industrial scale it runs on 220 volts and it'll process 500 lb of meat and mix and grind 100 pound bag of ice like it wasn't even there. You could buy the size of machine you need probably could get a used one fairly reasonable. I don't know the electrical needs other than it's a 220 volt machine but I know the 500-pound capacity machine would go through 500 lb beef shoulder and 100 lb bag of ice in process it in less than 5 minutes so all you're talking about is v i mean that the outside 10 minutes electrical use to process 500 lb of material. And if you put it directly in line to the digester it would mix and grind and pump that material rate into your digester all-in-one process I don't know if it would work exactly but I ain't no with the right size plate on the grinder those machines will eat just about anything including human terms we had one guy try to feed his arms through it and the Machine won, he lost. So depending on the amount of material that you would be processing everyday poundage wise that's the size machine used by if you're only going to put a hundred pounds of material in a day you buy a hundred pound capacity mixer grinder instead of catching the meat at the end of the grinder used put a pipe that goes directly into your digester and it will stuff it down that pipe I guarantee it and the smaller you get the less energy it would take so you'd have to be pretty close on your guesstimation how much material you needed to process daily and like I said it'll process 500 lb of meat in about 5 to 7 minutes that's mixing grinding and stuffing all at the same time
I would make you a mini shredder, like the dual shaft rotary knife ones on youtube. Except I'm half the world away.
Perhaps a local technical college could take on your challenge? I work at a polytechnic teaching machining and this would be an awesome challenge project.
Did you ever see myth busters when they floated a boat with ping pong balls? The had a funnel on the surface with a pipe down to the boat fill with ping pong ball and pump water into the funnel. If you can sink ping pong balls surely you can sink salad??
ruclips.net/video/4MOJN07XRYw/видео.html
Consider trying a good used working concrete pump (trailer/stationary) may need to add water and possibly pre shred.
Or a Vaughan Chopper Pump they are costly thou.
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H hope this is of help to you look up professor th culhane he uses an insinkerater for grinding food waste, he has many videos on RUclips and is passionate about biogas he may be able to advise you with regard to loading the digester he also has puxin moulds and has built many digesters around the world
What about a Timberwolf Wood Chipper? Would Timberwolf assist? It would chip things down and you can put it into the house toilet and pump away into the digester.
Hi Jeff, maybe someone else already gave you this answer already, but what about like a kitchen disposable unit? Just a thought. I've also saw what you were talking about the Muffin Monster, They have a 10K Inline Muffin Monster but don't know the price for it. Maybe a DIY project for you? ask Cody if he can help?
Hello TRM, hello from northern Ireland. You asked for solutions. Given your design as it stands and assuming you want a quick and low cost fix without processing I've thought of the following. 1. A two stage plunger: 1.1 outer plunger to drive down the large volume of material (if this works 2nd stage may not be necessary) 1.2 for the narrow 8 inch pipe 2nd stage steel plunger end on steel shaft. PROPULSION I'd use a heavy duty nylon strap with a ratchet (low cost & practical with option to improve using electric winch if it does your job, strap give extraction if stuck). Risks: it may be that the outer plunger doesn't drive material into smaller pipe. id test the narrow plunger on the nylon ratchet first. MY IDEAL - If I was building your setup I'd widen the intake and have a single diameter wide pipe, I'd plan to use a floating barrel on top of the waste and flood it with water from the outflow to apply large force and manage displacement within the tank reversing the pump to re-float the plunger. Just my thoughts, look forward to learning what you actually did. Richard
No choppers, no grinder pumps. Look at tub hay grinders. I'm sure you can get a small scale grinder set up pretty easily. Can run it off the PTO of your tractor. Output media size is controlled by a screen. should be able to make all your material small enough to go through the grinder pump then. Yeah it adds a step but it's a start. Once it works, make improvements.
What If...
Could you have two (or more) perforated pipes, one inside the other, that rotate in opposite directions. If the material were loaded into the center, the material would fall through the holes and be cut as the pipes rotate. Material between the pipes would be more or less ground together further processing it. Once material is small enough to fall through the outside perforation it could be loaded into the inlet or into your "horse toilet" for introduction into the digester system.
I'm thinking of a combination of a dirt / rock sifter and a sausage grinder to process the material, add some liquid as needed, and deliver the chewed up goo into the inlet.
Material handling not known... you got to be kidding... locate a Seattle marine engineer who works on at-sea factory trawler or longliner with waste sump Monster Industrial grinder-shredder from www.jwce.com/product/ into a slurry then flume and de-watering before digester... takes lots of water otherwise buy a tractor with a big bucket to transport the waste to the digester... btw, be sure to curtain off digester from green house with forced air source and exhaust.
If you could take 2 drums, rotating at the same speed but opposite directions, you could put the material between the 2 and crush it. If you could place blades or sharp edges that overlap in the opposing drums you should be able to cut, or at least bend, materials like straw enough that the pump will pull it through and grind it. On your level you could put a simple gear system on it to increase torque and hand power it. I'll try to come up with a simple drawing to send you.
The animal waste issue is definitely one to think about. However, the food waste from the living quarters is a bit easier to solve. Create a preprocessing unit at the living quarters for processing the food waste. I see two possible solutions depending on the willingness of the people involved. Either use an industrial food processor to shred the food waste or create a separate unit at the sink incorporating a garbage disposal and a catch system. Empty daily.
A manual operated grinder. Use only once a day you said, so that will be doable. Pull up your sleeves Jeff! Thumbs up! :)
The main thing I am learning from you is: first, move to a warmer place.
Any thoughts of using the tractor to power a pump? You have both a PTO and hydraulics so could use ether one to operate a displacement pump between 2 6-8 inch swing check valves so anything that can fit inside that valve can be pumped into the tank. Could turn a 6-8 inch T into a pump chamber with a check valve on ether side and a piston traveling up the vertical pipe section as a low speed crank shaft is easy to make.
your issue seems to be, to me at least, not floaty bits so much as your use of water as a safety airlock. So instead of focusing on how to make stuff not float, rethink the air lock. (side question - cant methane disolve into and pass through water anyway?)
Thankfully, you will be doing your loading in batches.
Break the system into logical parts. The main bits are the digestion chamber and the feed chamber.
To connect the two, you need a sytem that lets bits in "as is" and yet prevents methane from getting out.
1. Really small scale, use a 55 gallon drum as the infeed where you put bits until you are ready to laod into the digester. The bottom of the drum would need to be attached to digestor with a simple sliding gate. The top of the barrel, use an air tight lid. To Use : Bits go into the 55 gal drum, close the air tight lid, slide open the gate, bits fall in, close gate. Built tightly, with a wide area around the actual opening, you will get very little methane escape.
You can improve on that, though not sure it is worth the effort, by angling the drop chute from the 55 gal drum to the digestor so that it enters the digestor lower down so less methane. (depending on the contents of the digestor (if there is enough fluid) you could have the drop chute enter under the fluid level.). Pretty sure you will need to do the angling so you can keep the infeed drum Outside the Hab.
You could also add another gate between the drop chute and the digestor.
Another improvement to consider with this model is the use of a temporary water lock between the gate and the drop chute. by adding a chamber below the gate that you can fill with water, you get your safety lock, but can drain (or move) the water at the time of loading the digestor.
You could even use a piston to automate the actual loading by having it open and close the gate on a schedule.
You would probably want to experiment with coating the barrel and the gate with something like silicon to make sure the loading goes smoothly (no sticking).
Old video so problem might be resolved by now, but the screw idea would probably work if you had the pipe on an angle. Just a thought might not be feesable if you gotta go a long way down, but the right slope/screw pitch combo would do it 👌
Hey TRM. I think I have a simple solution to resolve your floating influent material issue. Have you ever watched any lacto fermenting videos, such as when you make Kimchi, Pickles or sauerkraut in mason jars? When people make those, they often place on a glass weight to hold down the food so that it stays under the liquid to prevent molds and bacterial contamination from spoiling the food. Essentially you're trying to achieve the same thing in the digester but on a larger scale right? Why not use a suitably heavy weight? I don't believe you can use glass in your application as alkali liquids react with glass (I understand the digestate is alkaline), but you could use HDPE plastic (number 2 plastic, i.e. milk bottles and caps). For example a solid 600mm diameter cylinder of 600mm length (or whatever diameter is slightly smaller than your feeder tube), would weigh 161Kg (look up a basic materials weight calculator 0.93g/cm3 and recalculate your preferred dimensions if necessary). I expect would be fairly simple to embed a few eye hooks in the top of the cylinder and connect chains to lift it out and place it down as needed. You could lift the weight up and out with a pulley /block and tackle system above the entry or make it swing out the way for safety as you feed the influent. You could easily shred, melt down and remold a bunch of plastic to construct such a disk I'm sure (have fun collecting that much plastic, get your neighbours or school kids to collect it). I cannot think that any of the influent materials you mentioned would be heavy enough to push back against a disk of a suitable weight. If left whole, the materials you are trying to digest, should not be able to escape around the sides of the weight so you don't need to waste time or energy grinding them them up really small either, unless your mixer would be prone to getting damaged from large materials.
Use a large heavy wheel with ridges to grind and break the straw stalks so you can send it through the grinder pump. Like a windmill, but powered however you want. You've got the infrastructure for wind power. Wind power might be just reliable enough to grind, or not. Just let the thing rotate all day and it'll self feed into the pump. Worked for ancient people with grains and wheat, not much different than what you're doing.
Scaling down a big system is a very very hard task. The efficiency goes down because of friction of moving parts and thermal energy loss because the ratio between surface and volume raises. More surface = more energy loss. Thats why all energy producing systems are so big. So i think its easier to go big...
Is there a way to put the large, heavy animals to work for you? They have mass and sometimes momentum. Is there a way to coach them to walk over something like foot peddle on a manual seeing machine? Make the animals earn their supper...
You should read John Seymour's "Self Sufficiency" (1976). His digester has a stirrer. Not sure he solved loading though.
Call Vaughn chopper pumps in Montesano Washington they should be able to help you
I did...very spendy
macerate new material to hydrate, then worm drive to push into digester, allows water back flow by not being too tight fit. This also avoids the slow break down delay of chunkies.
I think an Archimedes screw would work perfectly.
It just working in reverse. Tube would need to be around 1/2 inch thick wall and a heavy screw and hydraulic drive. If its built strong it wont matter if the hay and crap gets stuck on the edges as the screw wont stop turning.
Would a cupped auger take the items down into the digester? I’ve never seen one before but It seems logical with the brief thought I’ve put into it. If the threads of the auger were the shape of a pipe cut down the center and wrapped around a shaft it might catch the material and pull it down into the digester. Just a thought. Good luck
Great job . Been watching you guys for the last couple years and love the work your doing. We are Fiberglass sewage tank manufactures and use a product called a flout for gravity no power discharge. This system packs a hard dose compared to older siphon methods. Would work like a standard septic tank feeding the proper sizing of digest-ate to the digester . Would even donate a tank if you like
I feel a patent coming on that may help pay for the prototype of hab 2, and possibly the miniaturisation for hab 3 😊 you may be able to use something like they use for shredding cars just a much smaller version basically 2 rotating cylinders that have 'knives' that cut the material into pieces the size of the knives 😊
Can you fill the inlet with something that has a different bouyancy than water which would allow the materials to sink?
For some reason washing machine agitator comes to mind or a paddle system like a vane type hydro pump.
I dont get hey there is water in the first place. You said it is there to keep in the methane. But the methane would just rise up trough the liquid as it is gaseous.
Just a suggestion what about a restaurant size they put it in the dishwasher you know garbage disposal
In the UK wood shavings is a well known alternative for animal bedding. It might be less trouble for your digester feeder?
Random idea but hook up the load pipe to a toilet to load stuff in with a high flow you could put allot of stuff in as long as it was mulched and the s shaped drain will naturally keep the system air tight (same concept as in a house)
Great video... would it be possible to take that chopper that is available and adapt it to run off the PTO on your tractor or a stand alone gas engine?
the solution to all of your problems could be chickens over a mech floor and an insinkerator
You need a grinder like they use to make ground meat like hambuger
What if you switched to saw dust instead of straw for bedding
flat plates on a rope.
Please expand?
Why not us a windmill and gear it to create high speed processor like a Ninja processor. Smaller system with free energy. It could be scaled to the needs of the farm.
You need an augur like wrangler stars juicer
if only there was a system to grind up garbage and centrifugally pump it down a pipe, we could call it "the disposer"
Can you use a chipper Shredder before the grinder?
Im a bairy Farmer use a manner auger or manure pump
Your work is amazing! You guys are such an inspiration!
Rainbow over the horse toilet 👍
Wait, how does a baby burb again? lol!
A few comments on your issues with the digester.
1. All animals fed on a high fibre diet and bedded on a straw type bedding + high fibre household waste such as you describe will always tend to float if put in some sort of a tank and will tend to form a thick crust which I see as a major problem for you a) feeding the digester and b) possibly also when inside the digester vessel.
The current commercial solutions to this are
a) Chopping before pumping into the store powered by tractor PTO power periodically from the temp storage vessel as the material builds up- which has been the main part of this video
b) installing a sequential stage bubbler system in the bottom of the digester that normally pumps air (but in your case would need to be gas) to get the contents to move and mix and remain in a "soup-like" form of solution or
c) the use of an angled propeller shaped agitator placed just under the surface to destroy any crust by causing a mixing and agitation effect on the whole of the contents.
The compressor for b) above is usually electrically driven and uses a manifold with numerous electro-valves to direct air via simple pipe work to different parts of the floor of the vessel in turn. The pump moves quite a volume of air but not at much in the way of pressure to be effective and generally works perhaps alternate days. Tractor power (PTO) is normally the power source for a) & c).
Wastewater 101, cellulose is an enemy, very hard to digest. Stems, leaves, seeds, rinds, have a lot of cellulose. Circulation of the digester, you need to circulate the liquid in the digester, either by a pump or or gas bubbler mixing system. This keeps everything from stratifying, which prevents good digestion. Lots of good grinder pump systems out there. Look up Tsrumi, Vaughn, Barnes pumps. Lastly, the University of California Sacrementro has an excellent mail order course that covers all of these items. Look up some local wastewater treatment classes in your area, better yet, find a treatment plant that has digester. Us Professionals love to talk POO and explain what we do. Hey, that rhymed!! Don't forget about pH, that's a real big one, what a mess when that goes low.
You have lazy horses that need exercise, right? A horse walker/exerciser connected to a remote slow turning macerator/mixer with a large container near the barn that everything get place, once macerated, pumped the content to the digester. The horses win, you win.
Woukd a toilet system not work?
So sounds like you need a masticator rather than a grinder
Use a bubbler in the tank to help keep the methane moving?
Hmmmm
Oh look a rainbow.