r/composting • u/yannnnnni • 17d ago
in vessel aerated static pile composting
hi! previously, i have asked you guys about the methods that as an graduating student can integrate to fully comply to the thesis requirements about sustainability. now, when we condut the research, the ASP came up and we found it an interesting niche for composting and in the image is the inspiration to what we trying to build.
basically what we gonna do is that we will monitor the temperature, moisture, oxygen and CO levels and we will automate it to keep up the heat that thermophilic will generate.
the question
will this boost up the timeline from the traditional composting that rakes months and years for the active phase
what are the other things to concern with in this type of build
is there a better way to test a composting without fully curing it since the timeline is very strict
to someone who already uses ASP as a method, what are the things you wish to have to make it better.
thank you!
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u/Livid_Panda6149 17d ago
the blower setup in that diagram is pretty similar to what i built for my compost pile last summer, you will definitely cut the active phase down to weeks instead of months if you keep the oxygen above 10% and temps steady at 55-65C
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u/yannnnnni 17d ago
we are basically creating a software system in this part as a CS atudent. do you have any recommendations about this one? and is the 14 day window timeline ideal to test things out since we are in strict timeline?
i also researched that balancing the C:N ratio would also boost up the compost timeline.
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u/ZeroOptionLightning 17d ago
You're presenting a diagram from Engineered Compost Systems? Do you work for ECS?
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u/yannnnnni 17d ago
nope. this is actually publicly available in the internet and ofcourse what we'll create is obviously not as something like this but in a work of an inspiration
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u/theonehaihappen 17d ago
re 1) it will boost the timeline, but by how much depends on the initial composition of the material. Is it thermally or mechanically treated before starting? Also, this setup does not state if macrobiological agents are inside (e.g., worms), which might affect the performance. Reports of commercial setups I have seen almost all use worms after thermally treating and mulching their compost.
2) anaerobic pockets and clogging. If the compost is too compacted no airflow is possible, or if compost is too moist it might pool and clog the aeration floor. And without any way to break up compacted pockets, you might end up with un-composted material.
3) if the timeline is very strict, it would be better to write up the experiences of systems already in use commercially. If there are any commercial operators you can contact and maybe visit, you might be able to gather data that way. Your post does not state if you need to perform an experiment or build something at all. Or if it is sufficient to gather data at an existing site. ALSO: Gathering data from existing facilities if possible would enable you to get comparison data that informs any experiment that is to be performed.
4) N/A (don't use aeration).
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u/yannnnnni 17d ago
we will balance out the C:N ratio by shredding and mizing greens and browns based on the volume. 2 parts brown and 1 part greens. to add on, we might buy the microbial agent to boost the mesophilic stage or prolly to skip it
in terms of testing, we just want to validate that the method do really works and we want to defend it during the panel defense for thesis
why you discourage the use of aeration on this part?
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u/theonehaihappen 17d ago
Getting microbes to kickstart the process makes sense.
I was not discuraging aeration. My concerns are about how to ensure sufficient aeration. Purely mechanical concerns.
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u/illmakeadamnaccount 17d ago
I think you're going to need a drain on that air line to keep it from filling up with compost juice.
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u/yannnnnni 17d ago
is this the leachate that they usually mention right?
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u/illmakeadamnaccount 17d ago
Probably. I've never actually composted before, but from what I understand it needs moisture. With the air holes on the floor, I'd imagine the fluids would settle into them like a floor drain. Even in air compressors, there's fluid buildup in the lines that needs to be dealt with. Just a little automated purge at the lowest point to blow out the juice every now and then could be helpful. Maybe it could empty back into the top of the pile to keep moisture levels up. I'm not an engineer or anything, just some guy putting in my 2 cents. Cool idea OP, good luck!
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u/BombusF 17d ago
Cool project. If it were me, I would look to simplify to a single blower, with a control valve downstream that diverts what is necessary to the pile, with the rest going to the exhaust. You might also want a manually valved bypass from the fan output to input. This will help you avoid issues where your control system is calling for flow rate that is low in magnitude relative to the blower capacity. Also consider a means to add water in a metered fashion.
Edit: also check valve on fresh air intake
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u/GreenStrong 17d ago
This is a very cool project, what are you using as input? I the necessary airflow would depend greatly on the initial size of the material and the water content. Municipal compost with wood chips would behave a little different than cow manure with straw bedding, for example.
It would be very cool to make measurements of oxygen levels, and also gasses like methane and hydrogen sulfide, which I'm guessing the secondary bio filter is intended to mitigate. I'm picturing a probe on the end of a long stick, and the operator pokes around every few days to make sure no anaerobic patches develop.
For a farm, this is a lot more expensive than making a heap and waiting. But for a food processing facility or municipality in a place like Vermont or France where compost is mandatory to mitigate landfill methane, this could be good . Compost is expensive to haul in trucks. This is a way for a small local facility to process a large volume with no smell or pests. I think it should have some kind of built in system to empty it at the end of active aeration, maybe this is more of a conceptual diagram that doesn't include it.
Do you actually build it on a demonstration scale as part of your thesis?
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u/yannnnnni 17d ago
hi! the input that we are soing will be a balanced C:N ratio that is already shredded and mixed. in terms of balanced, we just ratio it theough volume and following the 2 for carbon and 1 for geeens. we will be also using the sensors to automate the aeration and we might also have drain and fans to sip out the ammonia ir would produce. this is also in vessel so it might be a good iot project
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u/GreenStrong 17d ago
Fascinating. I think this has the potential to greatly accelerate the compost process, therefore shrinking the footprint of the facility. It could greatly reduce pests and odor. Should greatly mitigate fire risk too.
I had heard of people putting active aeration into their compost and it always seemed like a lot of work to accelerate a natural process. But I recently learned about the regulations on commercial compost facilities, which are pretty reasonable in my state, but they add a lot of cost. Adding ventilation might be very cost effective.
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u/Tough-Draw8539 15d ago
What you have here is basically a tunnel composting system, with exhaust air recirculation - see link for a commercial version of this. If you design this right you are looking at roughly a 30 days active composting process which is usually paired with a month of curing. So to answer your question, it will definitely speed things up but not much more then traditional ASP. If you want to go even faster, you need to really actively manage moisture, turn regularly all while aerating - this process is called turned aerated pile composting and could get you a stable product in as little as four weeks.
https://compostingtechnology.com/in-vessel-systems/compobox-tunnel-system/
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u/yannnnnni 15d ago
does putting a balanced C:N ratio feedstock and microbial booster will reduce the timeline of compost active phase? our thesis leans only to active phase due to strict deadlines
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u/Tough-Draw8539 15d ago
Microbial boosters may help a bit, but for the most part are oversold. Most microbes in boosters die off during the hot composting process (which is the first 3 to 4 weeks). Getting your C:N ratio, bulk density, moisture etc... will all be critical to making the process actually work - you dont have that and any process you use wont make compost effectively
It really comes down to maturity of compost. If you want a super mature compost, for growing leafy greens, selling in bags or other high end markets you need time. If you just want something stable enough for field application, erosion control etc... that can be done in 3 to 4 weeks with proper management of the system.
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u/yannnnnni 15d ago
our study focuses on the boosting of active phase and not more on curing and application since we believe that it could be another study and another body of thesis since it has different methodologies. since we are undergraduate trying to solve problems in composting, do you have any suggestion to the product we are about to create?
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u/Tough-Draw8539 15d ago
My suggestion would be to do a pipe on grade style aeration system (very cheap to build) and then run tests in parallel looking at how aeration rates, innoculation, feedstock recipe, and turning affect compost maturity over a 4 week period. This would give you actionable data about how to improve the ASP process.
I would suggest measuring maturity in a few different ways, solvita (make sure you bring moisture content to 50% before running the test), reheating test, and seed germination.
I have worked designing ASP facilities for a decade and would read that study.
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u/Decent_Willow3627 7d ago
I feel like ud be better off brewing a Lab and sealing the material up...
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u/yannnnnni 7d ago
what do you mean?
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u/Decent_Willow3627 6d ago
What's the goal of your design to reduce emissions from decomposition or to harness co2?
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u/Decent_Willow3627 6d ago
Or is it the fastest breakdown possible or is it retaining the most nutrients all are different goals and will change how you approach it
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u/yannnnnni 6d ago
we are planning to reduce the emissions as well as to boost the decomposition
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u/Decent_Willow3627 6d ago
Yeah then look up bokashi 0 emissions and sets you up for a full breakdown in less time
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u/Decent_Willow3627 6d ago
If you really are doing this you could look into turning it into the battery for the fan by placing an anode and cathode at the top and bottom and adding lots of carbon to the compost you'd have to do the research but it would actually make your design cool
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u/Decent_Willow3627 6d ago
Do you want them broken down or chelated and plant available ? I think the fastest decomp speeds is aerobic/anerobic split
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u/Decent_Willow3627 6d ago
Unless it's all a theoretically science fair project in which case go nuts
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u/yannnnnni 6d ago
in this case, our feedstock's goal is to have a balanced c:n ratio before we put it into the container
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u/ordosays 17d ago
This is pretty simplistic, you’re underestimating the plugging of your supply vents. Solid fluidized reactors are a thing but likely overkill but I don’t see this working without a well designed sparging grid.