Jean Pain Method

This is one of those ideas that grabbed me when I first saw it years ago in an old Mother Earth News. Jean Pain was a Frenchman who lived in the French Alps, mostly a conifer type monoculture. Hardly any topsoil. He worked for the forestry service, or whatever they call it over there, clearing firebreaks in the forests.

Long story short, he had access to a lot of carbon rich compostables. Now he could have done a hugelkulture (sp?) berm type project a lot like his neighbor over in Austria, but he had other ideas. He chipped the woody mass into little slivers and made huge piles of it, completely saturated it with water, and it began to compost.

Composting, as we all know, generates a great deal of heat when done properly. So he devised a way of stringing black plastic pipes in loops throughout the pile and running water through it. What he got was about 140 degree water (fahrenheit I believe) at about three gallons per minute.

Taking it a step further, he buried a pressurized tank full of the same material in the top of one of the piles. With the constant temperature of the composting, he pulled methane off of the captured compost and stored it in inner tubes. Apparently he scrubbed or distilled it somehow to remove excess water and impurities and used this gas to cook and heat his house, and power his vehicles and even provide the fuel to chip and stack the piles of compost in the first place.

I find this creative. It's possibly (somewhat) sustainable. Low impact. And uses wastes to create a useful end result and two, maybe 3 by-products.

He made about 50 ton piles which is something like 30 feet in diameter and 10 feet tall. They apparently reached maturity (hottest) in about 3-4 months and started losing vitality at about 14-18 months, at which time they were broken up and used for garden soil, improving the fertility of his property.

He wrote a book, which was apparently poorly translated into English, and not that many were sold here in the states. He also died prematurely of a heart attack in the early 80's, just as he was starting to work the bugs out of his system and start to promote it.


So. In a nutshell... I'm looking for a copy of the book. I'm wondering if anyone has ever tried anything like this, and it never hurts to know just a little more about those that have done something amazing.

I know of some folks on the east side of the cascades that are doing a lot with this sort of thing.

I, too, would like to see the book. 

Does the book have a name?

Here is something pretty close and much newer.

The book is The Methods of Jean Pain: Or Another Kind of Garden, by Ida and Jean Pain, in English, self-published 1980, 88 pages, with photos.

An old article from Reader's Digest:  http://journeytoforever.org/biofuel_library/methane_pain.html

Photos:  And http://www.permacultureactivist.net/PeterBane/Jean_Pain.html

Dated 9/8/07 (do you think this is correct? They speak of him in the present tense.)
"EDITOR'S NOTE: You can order an English translation of Ida Pain's 88-page book about Jean Pain's techniques Another Kind of Garden: The Methods of Jean Pain, Seventh Edition in English-by sending a $20 international money order to Ida and Jean Pain, Domaine "Les Templiers", 83980 Villecroze, France."    http://tribes.tribe.net/permaculturetribe/thread/8692a862-bec9-4eff-b16d-ae541c0a8837


"For anyone interested in Jean Pain's methods of producing energy from compost, but frustrated at the lack of information and the scarcity of the English edition of his book, I found a nice video about his methods that is narrated in German and is about 15 minutes long.  I think this was also posted at the stoves mailing list, but didn't make it into our archives yet.  '

Jean Pain video  http://video.google.de/videoplay?docid=1718032861615687313

Sue

Excellent links.  I'm still reading through them.

I have to wonder about the amount of work and materials and the amount of benefit.    Does one, perhaps, spend $1000 on materials and 60 hours of time to get $800 worth of fuel?  And then the next year it might be more like $100 + 40 hours to get $1200 worth of fuel?

My major question is how does one "scrub" the methane to purify it? It's almost glossed over like it doesn't matter, but it does... a great deal in fact.

I have access to several local sawmills and i have thought about using their excess in this manner as a test bed. The sawdust is free, and with the kind of equipment my family has access to, that's about 3 trailer loads to make a 50-70 ton pile. Maybe one good day of work, and then sit back and see what happens.

Might be worth a try. I'll give it a shot... maybe tie it in with a radiant under-floor heat and see what that gains me, if anything.

Try googling 'methane scrub' and lots of stuff show up.

Sue

Yeah, I'd like to get some rough idea of what this scrub stuff means.

My understanding is that there are two somewhat corrosive substances found in raw methane. One can be removed by passing the gas over iron oxide, i.e. rusty steel shavings; the other is removed by bubbling the gas through lime water. This begs the question, "what sort of lime" ?

I, too, am an avid Jean Pain fan from back when I first stumbled across the Mother Earth article referencing his work. I've been composting on an industrial scale ever since, having applied twelve inches or more of the finished material to, roughly, twelve acres of ground. I have yet to see the productivity and benefit of heavily composting soil max out. Taste, size, disease resistance, keeping quality, drought resistance and plant appearance continue to improve every year.

The only other portion of Jean's technology that I've yet to apply is compost heat.
I poured three large concrete bays against the east wall of my home several years ago and use those bays to construct and maintain three compost heaps. Two are always aging. One is always under construction. I heat the house exclusively with a wood stove of my own construction, and noticed a considerable difference in the amount of wood required to heat the home the first year the compost bin assembly was in place. Ambient temperature in the home was increased by approximately ten degrees that particularly cold December.
I built the center bay a bit larger than the outer two with the hope of eventually placing a large stainless tank over it to collect rain water, and subsequently heat that water as it passed through copper coils imbedded in the compost below, to provide hot water for the home. My bins hold about twenty tons of compost material each. Situating the piles so close to the house has not been a problem.
We compost humanure right along with everything else, as described in Joseph Jenkins' "Humanure Handbook", and find that ALL unpleasantries are summarily eliminated through the use of a carbon cover. We use sawdust, straw, leaves or wood chips to accomplish that end. Having the pile right outside the kjitchen window also saves multiple steps in disposing of kitchen waste. 

As I recall the Mother Earth News article, Jean was running the warmed water from the buried plastic pipe through the radiators of his house to heat it. The methane creation was an added bonus. I have all the MEN issues on a CD and will try to find the article. I believe the he used a mixture of wood chips and Horse Manure in layers. I think it could be used to heat a radiant floor system. I also remember Jean saying that the size of the chips could be manipulated to get more efficiency and that he was working on a modification to his chipper to produce better chips.

Better chips = smaller and thinner, according to what I've read of Jean's experiences.
Smaller chips offer more over-all surface area for the methane producing microbes to feed upon, thus a more efficient use of the vegetable matter and perhaps quicker release of the gas.

A simple way to scrub methane is to cool it.  Winter temperatures will condense water along with most acids, although it would be important to allow liquids to drain somehow.  Providing lots of surface area for this condensation wouldn't hurt.  Methane doesn't liquefy easily, so it can be made very pure if you're willing to use low enough temperatures.

I bet "lime" here means "cheap pH-increasing chemical".  Presumably they mean slaked lime, CaOH: it's the only form you can really bubble through. 

Let me know what those two chemicals are.  There are probably many, many ways of handling each of them.

polyparadigm,

What happens if you have an upside down plastic bucket over a steaming pile of poop on a windless day?  Will some methane like stuff go up and "fill" the bucket?

paul wheaton wrote:
polyparadigm,

What happens if you have an upside down plastic bucket over a steaming pile of poop on a windless day?   Will some methane like stuff go up and "fill" the bucket?

AFAIK a modest amount of methane, H2S, and other anaerobic products will be released along with the first amount of water, until oxygen kills the gut flora in the center of the pile.

If the pile is large enough, aerobic bacteria will use up all the oxygen, and the condensed water running down the sides will keep it moist enough to produce a methane-nitrogen-CO2-NH4-H2S mix in the bucket.  If it's really huge, the nitrogen and CO2 will tend to be flushed out the bottom by the outflow of gas, and the condensing water vapor will absorb many of the other impurities, giving fairly pure (but still moist) methane. 

If the pile is small, it will mostly dry out and aerobic processes will dominate its decomposition.  Further, microbes on the wall of the bucket will eat the gasses listed above, making CO2, nitrate, and sulfate.

If I had access to vast quantities of woodchips and space enough, I'd consider growing mushrooms.

If I wanted to compost lots of C-rich material, I might consider growing potatoes with the "cage method" but including a moderately fast-spreading legume (medick?) to feed the spuds and the decomposition. 

http://www.gardencityseeds.net/growers1.php

I remember reading about Jean Pain's ideas in TMEN years ago.  My (ex) husband wanted to try it, but we didn't have access to the huge quantities of material required.  Most people with a lot or small acreage aren't going to have enough compostable material to do this (unless, like Quittrack, they have access to material from another location).  It's still a good idea, though.

Kathleen

Gonna try this again. 

Here is my poop.

Here is my upside down bucket. 

All on a windless day. 

I suspect that biogas will be lighter than air and, thus, move up.  And the air in the bucket will be displaced with biogas.   

Would this be accurate?

It might not be much, but it would be some. 

Further, I suspect that if I were to make the poop be in something anaerobic, then I would get, perhaps, ten times more biogas. 

Accurate?

Pretty much.

Except gas diffusion is more rapid than liquid diffusion, so even with air that is macroscopically still, with laminar flow from the manure, etc., the microscopic motion (individual molecules crashing into each other) will tend to dissolve air into your collected biogas and vice-versa.  Over time, it will siphon itself out from under the bucket.

So the biogas in the bucket will degrade into ... smelly air?

paul wheaton wrote:
Gonna try this again. 

Here is my poop.

Here is my upside down bucket. 

All on a windless day. 

I suspect that biogas will be lighter than air and, thus, move up.  And the air in the bucket will be displaced with biogas.   

Accurate?

Polyparadigm is right; gasses tend to disperse rather than accumulate in reliable layers.  I suspect stinky air is what you got.

Best way to test it - will it burn?


To geek out over gas densities:
Density / weight of a gas corresponds to molecular weight
(At a given pressure & volume.  Volume corresponds to total number of molecules)
For gasses only (no fog or condensed water),

Methane is CH4, total molecular weight: 12 + 4 = 16.

Hydrogen is H2, molecular weight: 2.
Water is H2O, molecular weight: 2 + 16 = 18
Ammonia is NH4, molecular weight: 14 + 4 = 18
Hydrogen Sulphide H2S, weight = 2 + 16 = 18
Nitrogen (most of the air) is N2, molecular weight: 14 x 2 = 28
Oxygen is O2, total molecular weight: 16 x 2 = 32
Carbon dioxide is CO2, total molecular weight: 12 + (16x2) = 44

So on balance, CO2 is denser than air, O2 roughly the same as N2 = air, and the rest of the gasses listed above are lighter than air.

I believe that commercial methane digesters use a trap that is either buried in, or completely encloses, the rotting pile o' poop, to ensure that there is not much contamination by O2 or outside air.  Anaerobic digestion is stinky, and the neighbors probably appreciate the encapsulation.
  Stinky compounds can include heavier-than-air aromatics, lighter-than-air sulphurs, acids, and heavy oily stuff like putrescine. 

  If you had a streaming flow of methane, like the flow of CO2 & steam from our rocket exhaust, it would probably pool in the upside-down bucket before dispersing.
  But since what you have is a gradual emission of methane, water, and other gases, and there's not enough air coming in to displace it and provide a strong upward flow (or you'd have aerobic digestion, producing CO2 and H2O instead of CH4), I'd bet that dispersal happens faster than pooling.

To find out:
Put a bucket on your steaming pile o' poop, come back an hour later, and try to light it on fire.  Maybe away from the barn.

A more controlled, and fun, version:
  Wrap your pile o' poop in an airtight membrane, plumb a vent tube out of it into a hose.  Drop the end of the hose into a bucket of soapy water, or if you wanna get fancy, use a jar of water as a bubble-trap (upside-down jar in bucket o' water, let the bubbles rise into the jar and displace the water until you've collected enough to play with). 
  Squirt some of the collected gas through bubble-stuff (dishsoap and glycerine or  corn syrup).  Creates little portable gas-packets to play with.  Take them out where open flame won't light off your whole barn or pile o' poop, and try lighting them with a long match. 

Watch out for your eyebrows.  I've done this with bubbles of pure methane whose total size is about as big as a baseball; I wouldn't try it with larger amounts until you've seen it.

We used to call it the "Methane Dragon."  www.OMSI.edu

-Erica
http://www.ErnieAndErica.info

I was going to geek out even further, computing the free energy of mixing versus the enthalpy gain from having heavier gas on the bottom, and show just how very favorable mixing was in terms of thermodynamics.

But I guess I'll be lazy and leave that as an exercise for the reader? 

Hi all.

The good people of Taranaki farm in Australia have uploaded a subtitled version of the German language Jean Pain video on Youtube.



Much easier than learning German from scratch.

There has been a bit of talk about people not having access to enough material to attempt this, but lets remember that you don't necessarily have to make a gigantic compost heap that will last 6 months to benefit from the method.

and you will be surprised by how long a good Jean Pain style pile will last.

Apparently Mother Earth News attempted to replicate the experiment on their test farm and constructed what they described as a "six ton" pile, versus one of Pain's "50 ton" piles. They used a standard wood chipper, which left their wood chips a little bigger than Pain's. They watered the pile to saturation as they built it, just as Pain described, and they jump-started it with a bit of hog manure. The report said that the experiment was successful until the air got cold enough later that winter to chill the pile below the temperature threshold where the composting could continue. Essentially their pile was small enough that it froze to death. Obviously this would vary by climate.

I haven't heard of Jean Pain, so I'm very glad for this thread.

I was planning on doing something along these lines to heat a green house attached to a home.  I reasoned that composting wood chips, horse manure and leaves under the planting beds would add heat, and I could grow some mushrooms too.  I now wonder if the gasses from composting would be a problem. 
I just can't shake Paul's - bucket - pile of poo - image 

Jami McBride wrote:
I now wonder if the gasses from composting would be a problem. 

Aerobic composting should produce only CO2, water vapor, and compost.

If things get slightly anaerobic, small amounts of H2S and NH3 may be released.  Not enough to cause problems, just enough to alert you of problems in time to handle them.  The real workhorse methane producers will be almost extinct, unless your pile really stinks.

Composting in a greenhouse is win-win, with the possible exception that it adds some weak positive feedback.  It releases slightly more heat and moisture if the greenhouse becomes hotter and more damp.  It should be easy enough to overwhelm these slight effects with stronger sources of negative feedback (automatic vents!), and to mimimize their effect by mulching and watering the pile enough that it runs fairly hot regardless of the greenhouse atmosphere.

Excellent video! 

Looking at the vid I have some questions:  how long does a pile like that provide all of that stuff?  My experience with compost is that if you get a hot pile going, it's done being hot in a month or so.

The primary reason I ask is that if it lasts 20 years, then this is excellent and what I want to do!  If it lasts one month, then it seems like a lot is put into the system and it's value is debatable. 

Which comes to another point:  all that wood chipping ....

and another point:  all that wood!

I just can't shake Paul's - bucket - pile of poo - image

Could that be the sign of true art? 

About 3 or 4 years ago I found Jean Pain's book through my public library in Belfair, Washington (Timberland Regional Library System), they did a national library search for me and I got it through inter-library loan. I think it came out of a university library in Texas. Great book! Ask your librarian to help you with the process.

A two minute video featuring a much simpler idea that is amazingly productive: 

The biogas digesters are a great idea.
No question about it.
But I think that the Jean Pain method is an approach to a different problem.

Jean Pain method
uses
-forest wastes and woodchips, effective at low temperatures
produces
-heat
-hot water
-solid compost
-can produce biogas if a biogas digester is incorporated
once built needs almost zero maintenance until it starts cooling (can be over a year depending on the size

Biodigesters
uses
-manure or vegetable waste
produces
-Biogas
-liquid effluent which can be used as fertilizer
-requires consistently high temperatures (mesophilic: 30-40°C; thermophilic: 50-60°C) for operation.
requires constant addition of fuel source and removal of slurry

I think they're different solutions for different fuel stocks, and in cool climates, incorporating both techniques together could provide a resilient and highly productive system.

Biogas generators are very commion in India and a simple google search will show what seems to be a standard design for the their use in cooking. The composted waste and water are used to fertilize and water gardens
One of the Florida Universities had an experiment with digesting cafeteria waste for biogas. I'll see if I can't find and post that link.
I've seen different types of scrubbers and condensers for removing water.
The Pain method made use of what he had and would be impractical for me but the simple Indian design does pique my curiosity and I'd like to try it on a small scale. I wonder how it would work with the waste coming from a garbage disposal and household grey water?

According to my reading, digesters tend not to be economical for a single household.  Essentially you need a cow or two's worth of manure in order to produce a usable amount of biogas for a family's cooking needs.

Hmmmm  ....  I wonder ....

What if I don't wanna do the chipper thing, but I do have a fair bit of sawdust and wood chips from different projects ....  And I'm not sure how big of a pile I want to do ...

What if there was a big pile of wood chips, branches and lots of bits and bobs of wood .... and urine - lots of urine .... 

So i get to thinking that something like this could provide a whole lot of heat and hot water over the winter and be a big receptical for urine during the winter.  Urine could be diverted to farming stuff during the warmer months.

Hi Paul,

As it happens, my first post on-forum is in reply to you...

paul wheaton wrote:
Gonna try this again. 

Here is my poop. Here is my upside down bucket.  All on a windless day. 

I suspect that biogas will be lighter than air and, thus, move up.  And the air in the bucket will be displaced with biogas.

Biogas is mostly methane (say 60% for stable digestion), and the rest, for this purpose anyway, is carbon dioxide. The methane is indeed lighter (0.717 kg/m3) than air (1.29 kg/m3), whereas the carbon dioxide is heavier (1.98 kg/m3).

But even given that, I doubt you would have much methane in your bucket, and I feel confident that, regardless, it could not be used for anything practical. Why? Well...

Further, I suspect that if I were to make the poop be in something anaerobic, then I would get, perhaps, ten times more biogas. Accurate?

In the illustration, the outside of the small pile would be aerobic, whereas the inside would probably be anaerobic, given that, in most mammals, the last portion of the intestine is anaerobic. (In humans, the last half of the large intestine.)

What will happen, I believe, is that most of the methane will be consumed biologically before it migrates through the aerobic zone, out of the anaerobic zone. In a similar way, hydrogen is produced in the biological pathways of the beasties in most anaerobic digesters, but it is consumed (converted to or used to produce other chemical species) by other beasties.


d.

Quittrack wrote:
Jean Pain was a Frenchman who lived in the French Alps.... he devised a way of stringing black plastic pipes in loops throughout the [compost] pile and running water through it. What he got was about 140 degree water (fahrenheit I believe) at about three gallons per minute.

Taking it a step further, he buried a pressurized tank full of the same material in the top of one of the piles. With the constant temperature of the composting, he pulled methane off of the captured compost and stored it in inner tubes. Apparently he scrubbed or distilled it somehow to remove excess water and impurities and used this gas to cook and heat his house, and power his vehicles and even provide the fuel to chip and stack the piles of compost in the first place.

Based on the video mentioned in other posts in this thread, please let me try to apply some physics, biology and math to Jean Pain's methods and claims, at least as far as biogas is concerned...

The rooftop tank on his car looks like a standard K, which is 9.25 x 60 (inches), where its volume at 1 atm is 1.76 cu ft. (That's all US tanks and units, of course, and JP was in France, but it serves for a starting point.) 250 psi is about 17 atm, and at such a pressure, such a tank would hold only 32 cu ft, which is the energy equivalent of less than 2 tenths of a gallon of gas. At 1,000 psi, such a tank would hold 128 cu ft (still far less than a gallon of gas eq). It would require a 3-to5 stage pump to get to the 2400 psi required to liquefy the methane, and of course, the energy required  to power any such compressor would have to be subtracted from the resulting energy.

His biogas tank was batch filled, clearly. The video says he fills it with partially digested compost, and that it is producing biogas after a few days, the implication being that it is producing biogas in usable quantities. That would be unusual, since there are generally rather few facultative thermophilic microbes (high temp-loving beasties which can live under either aerobic or anaerobic conditions) in aerobically composted materials. Further, the microbes (they are archea, not bacteria) which actually produce methane are obligate anaerobes: they would not survive being exposed to oxygen, and would be unlikely to be found in a well-built compost pile.

In a digester fed something easily digestible, such as food wastes, at peak production, one may get two digester volumes per day in biogas, which of course would be about half CO2. Jean Pain was using materials that it would be difficult to digest: mostly woody wastes. But set that aside, and assume that he is getting two volumes of methane per day (i.e. somewhere between four and ten times what he could possibly have gotten).

His digester appears to be about 4 feet in diameter & 6 feet high, which would mean that it has a volume of just above 40 cu ft. So even if make out-sized and unrealistic assumptions, the digester shown in the video would be calculated at generating around 80 cu ft of methane a day. Every dry cu ft of pure methane has 912 net BTU. Gasoline has energy content of 114,000 BTU/gal, so it takes 125 cu ft to directly equal the energy in one gal of gas. Generally speaking, however, methane is not the direct equivalent of gasoline when using both fuels in a given engine. Methane will usually not burn as efficiently, so that less of the energy in the methane comes out as mechanical force.

So given all the fudge factors in his favor, he would only have been able to produce the energy equivalent of a gallon of gasoline every day and a half or so-- and assuming that he is not burning any in his stove to make tea, etc.... (But again, realistically, he was likely producing somewhere well below a quarter of that, and note again as well that these calculations do not take into account the fuel used to cut and gather the wood, run the tractor for shredding, the power for the compressor, etc., etc.)

In sum, yes, perhaps he could run his car off a long hose for a while, but he will not be going to town using a K-sized tank at 250 psi.


The summation, it seems to me is that there would be less work involved in feeding wood into a stove to produce hot water and for cooking, vs. creating that enormous compost pile after all the energy which has been put into shredding and stomping, etc. I don't know, for certain, but it does seem as though Thoreau, using technology that was essentially older than the millennium, would have gotten rather more energy out of Jean Pain's wood than Jean Pain did, using 20th century technology, and with a far lower carbon footprint.




I' m not trying to say, here, that no one should adopt Jean Pain's methods. But let the buyer beware. What has been claimed does not pencil out. Cooking? Possibly. Space heating. Perhaps. Powering an old Ford pick up? Um... no. If someone wants to buy a carburetor which the seller promises will turn his 1969 Chevy into a 100 mpg car, have at it. But it may be more realistic to get the Chevy all spruced up, sell it as a classic, and buy a Prius.

Mind you, I'm certain that biogas has enormous potential-- Indeed I can prove it-- but assertions should be put to the test, at least as I see it.



d.

I thought his pile looked like it had a diameter bigger than 4 feet.  In fact, from my foggy memory, I would guess 12 feet.  Which would make it about 36 times bigger.  If my foggy memory is correct (which seems unlikely) that would mean, according to your calculations, he was generating an equivalent to 24 gallons of gas per day.  Which should be plenty for all sorts of stuff. 

David,

Hmmmm ..... thinking about this ..... thinking about a tank that might be 10 feet in diameter and six feet tall, and partially buried ....  I wonder if it could be seeded with a lot of material like that and then certain material from the house could be routed to it throughout the year  ...

Could something like that be kept going indefinitely to power/heat the house and fuel a car?

paul wheaton wrote:
I thought his pile looked like it had a diameter bigger than 4 feet.  In fact, from my foggy memory, I would guess 12 feet.

The compost pile, yes, I would agree, is rather larger. My comment was about the digester:

DavidHouse wrote:His digester appears to be about 4 feet in diameter & 6 feet high, which would mean that it has a volume of just above 40 cu ft.

I don't know about how much energy someone might get out of a compost pile over a period of time, but I do know that compost rather rapidly goes anaerobic, if not turned, and I would doubt, therefore, that such a large pile would remain aerobic for anything close to a year.


d.

Sorry-- I didn't respond to your other point...

paul wheaton wrote:Hmmmm ..... thinking about this ..... thinking about a tank that might be 10 feet in diameter and six feet tall, and partially buried ....  I wonder if it could be seeded with a lot of material like that and then certain material from the house could be routed to it throughout the year  ...

Could something like that be kept going indefinitely to power/heat the house and fuel a car?

Most certainly such a digester could provide cooking fuel, but powering vehicles is something else again.

With a radius of 5 ft and a height of 6 you have a volume of just less than 300 cu ft, or a bit over 8 cu m. That's a pretty big digester (at least for homestead situations), of the sort that should be fed the dung from (say) 6-8 cows, or a comparable amount of digestible wastes. (i.e. ~120 lbs per day. For example, I used to make compost from food waste that I picked up from a fast food place. That was about 150 pounds a week. If the restaurant had been quite a bit larger or I had picked up from more places, then I might have been able to feed an 8 cu m digester...) But the first point is precisely that: you have to have enough organic material to feed the digester. (The waste from one adult, by the way, can be expected to generate no more than 1 cu ft/da biogas. Not much.)

Second, the rate of gas production will depend on a number of factors, but the two primary are the temperature of digestion and the type of substrate-- the organic material used to produce the biogas. (For anyone used to making compost piles, you know that different things decompose at different rates. Fresh green material will, for example, decompose far more rapidly than woody material. The same thing is true for anaerobic digestion as is true for aerobic composting.)

The temperature of digestion for a very simple digester will be controlled by ambient temperature, either of air if the digester is above ground, or of the earth if below. One can put the digester in a solar greenhouse, leave it unheated, bury it, and so on. The temperature underground will generally be roughly the average annual air temp, so warmer in the winter and cooler in the summer than ambient air.

Since the microbes that produce the biogas have adapted to guts-- yours, mine, and those of all mammals-- then as you might expect, body temperature is what they prefer. (There is also another group of anaerobic microbes which likes a higher temperature range, of the sort you get from the middle of a really active compost pile, say 140-160 deg F.)

A digester fed the right stuff and kept at body temp will usually generate about 1 unit vol of biogas per unit vol of digester. So in the case of your proposed unit, you can expect about 8 cu m of biogas per day, if you feed it correctly and keep it warm. An underground unit of the same size fed the same stuff might generate about half that amount of biogas, because it would be colder and therefore all the metabolic activity of the bacteria would be that much slower.

For the sake of argument, then, let's say that's our range: 50%-100% of the vol of the digester per day, or in your case 4-8 cu m biogas per day.

YMMV, as they say, but it might take ~0.6 cu m biogas per day to cook the meals and provide some light in the evening (in Coleman-lantern-like lights). So far so good, but the real problem comes with trying to power a car, as in the Jean Pain example. An ICE will require ~0.45 cu m biogas per HP per hr, so if we have a little car with an 80 HP engine, then we will need 36 cu m biogas to run it for an hour. Just starting it up and getting it warmed up for 5 minutes will take 3 cu m.

In order to run even a little car for just a little while, as should be plain, it will take a large digester, which has to have correspondingly more organic material to it, which requires correspondingly more effort and so on.

The point, at least from my PoV, is not about biogas, it's really about the design of our cars. They swallow worlds and pollute the atmosphere.

Finally, however, I note that all the studies that I have seen show that biogas is nevertheless rather more efficient at generating fuel per unit land than is either ethanol or biodiesel, and it does that with a smaller carbon footprint. I can send you links to demonstrate that if you wish, but a stat that is widely quoted on the I-net is that the plant matter from 1 hectare of land (about 2.5 acres) will produce enough fuel to drive a car 70,000 km. Note, however that there is general agreement that if the biogas is used to produce electricity, and the electricity is used to run the car, the outcome will be more miles than if the biogas is burned in a car's ICE directly.


d.

Hi all,

I have been working on the Jean pain method for about 6 months and just getting started to learn.

I have some good results...

[youtube]http://www.youtube.com/watch?v=yILWqdeGt_M[/youtube]


and some not so good.

[youtube]http://www.youtube.com/watch?v=5O1LyKGuKU4[/youtube]


I have taken some notes from what I have found here, but here are some other good links I have found.


But here are some good links on this issue..



http://www.pandscorp.org/Hot-Compost.html



http://www.green-trust.org/wordpress/2009/10/11/hot-water-and-methane-plus-compost-from-wood-chips/



http://mariposagardens.org/Handouts/Composting/Compost_Festival_Displays.pdf




http://energymd.wordpress.com/2008/12/05/heat-free-nearly-with-a-compost-furnace/

Cheers! 

After reading this thread, I have wofati and thermosiphoning on the brain.

This topic is covered a bit in podcast 017

This podcast covers a LOT of different topics!

As mentioned at the beginning of the podcast: email signup.

We start off reviewing the movie "Food Matters".  The premise is that many diseases can be resolved by food choices.  And this has been discussed several times at the forums.  A good start is my thread on eliminating medication with polyculture; and the thread about beating  cancer; 

We talk about raw food; local food; the missoula urban demonstration project; composting toilets; outhouse; urine diversion; women peeing outdoors; hugelkultur; rain barrels; greywater; commercial compost; art ludwig; pee powered cars; jean pain technique; poop beasts.

Paul, Caleb, and Krista talk about hot water in this podcast: hot water podcast

They talk about the Jean Pain Method.