The Methane Midden: Epic Shit & Jean Pain Composting

Jean Pain was a visionary in the Provence region of  France during the 1970’s.  He was charged with protecting over a thousand of acres of woodland from fire, but his quick and able mind, love of life long learning, and a deep concern for the future of our Earth led him to accomplish something much more indeed.  Jean Pain spent a decade working through the techniques of a fantastic system to use the ever renewable waste brush from his woods into life giving humus. But then Jean took it to a entirely new level – he began to heat water in his compost piles, enough that he heated greenhouses and his own home.  Never content to sit on his laurels, he then began studying up on methane production- and he put a batch methane digester into his piles to use the “waste” heat from the bio-reactions to provide the ideal environment for methane production.  Before he died, his techniques had reached a level that he was able to produce methane and hot water for up to 18 months – enough for two winters – while also powering his truck, cooking, and producing electricity with the methane gas. My favorite part? No special machines, just a deep understanding of Permaculture before the word was even coined.  Partner with Nature to meet your needs.

Jean Pain was a visionary, but his techniques, if anything, are too simple.  Let me explain. They are not sexy at all.  Try writing for a grant to heat water with rotting garbage while going up against a Solar Hot Water array or a wind turbine, let alone algal biodiesel or whatever comes next.  Compost heat doesn’t create jobs; doesn’t need research studies and cannot be outsourced so it has no place in the Global Economy.  Know what?  Neither do I .  Jean Pain is a hero of mine for doing something that no one cared about because he knew it was just so very right and would be necessary to help save us from ourselves.  I read an awesome quote this week that pushed me over.

The time has come to do Epic Shit.”

-Larry Santoyo, Permaculturist

Right f/king on Santoyo!  Let’s do this!

Last week I scored a dump truck load of VERY green chipped mulch.  The rest is now history.  This project is going from drawing board to reality far quicker than I typically work, in fact the next step is typically being formulated as I am driving the wheelbarrow on the step I am currently on.  I knew I was going to do it at my home – that meant keeping it tight on space, visually acceptable, and must fit into the current plan.  Finally, it was to be a temporary structure – 6 months at most.  So I ended up with a 12×10 foot print using straw bales to contain the mulch.  Why Straw?  It has structural rigidity, is a great insulator, but also breathes.  The 16″ thick bales would contain the pile into tight angular dimensions and keep the dogs and kids from knocking the pile down.  The insulation would help me get away with only a 2′ thick compost layer around rather than the 3′ I would have preferred if I had more space and material. The following with be a pictorial journey through the afternoon today – with the help of my friend Kevin, we completed this in about 4 hours.

First I prepped the ground by removing a perennial bed that had succumbed to quack grass.  I chopped the ground up with a mattock as much because the quack needed punishing, but also because a mattock is possibly my favorite tool to use of all time.   Then leveled it with some old wood chips to make it look pretty.

 

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10x12 - in the background you can see the chips soaking in their bins.

 

Next up was to lay down some temporary weed barrier for the quack, and start building the sides.  Gods do I love to build with straw – so fast!

 

Bales are on end to save space and stitched together with 2' pieces of rebar for some rigidity.

 

Next up was to throw some mulch down to hold the cardboard pallet slips down, and then put the two steel 55 gallon drums in place.  The drums will act as the batch digesters.

 

Now the Methane Midden is really taking shape - Woot!

 

With the digesters in place, it was time to put in the heat exchanger.  Compost will heat up ALOT.  The material for this project was at 140 degrees 3 days ago before we broke down the pile to soak it.  Methane production occurs between 85 and about 103 degree.  Over about 105 the bacteria start to die off, 101 is about peak production.  Jean Pain figured out that you needed to cool the digerster tanks, so he pumped water through a hose wrapped around the tanks.  So I bought 240′ to augment the one hose I could spare.  After cooling the tanks, the hose is then laid out throughout the pile to absorb some of the heat from the composting, so the exit water is up to pile temp, typically 130-150 degrees!

 

290' of hose wrapping the two barrels, then we threw in 8" of soaked mulch and laid on our first row of heat exchanger.

 

The hose is essential to pull the heat from the pile, and it takes a 60′ hose laid out like this to make one lap of the composting layout.  I did absolutely no math on this point, the hoses come in 60′ chunks and we laid them out to make one fit per layer.  I figured 6-8″ between layers should be enough to both heat the water in the hoses, but not too little that the water pulls so much heat that the bio-reaction is slowed.  Time will tell is my intuition was off.

Here we are about 75% done, laying the fourth and final “rung” of heat exchanger:

 

Isn't it GORGEOUS?! This project just feels so right!

 

That is about as far as we got today.  I ran out of mulch about half way through the next layer.  I will finish the pile alternating leaves and grass clippings.  Would like it to be mounded over the top of the digesters about 8″ and will then cap the entire pile with either straw or mulch for insulation and to prevent evaporation.

Some items that maynot be evident in the photos.  The heat echanger is set up counterflow.  That means that the coldest water enters at the top of the barrels- which is where the slurry should be warmest, and then runs through the 290′ of hose around the digesters.  At that point it is at the bottom of the pile, at which point it climbs 4 “rungs” of 60′ hose laid out about every 8″ through the pile.  Total hose length is 530′  for no reason other than that was what it took to do the above and “make it look right” – no fancy math here, just intution.

Still have some very serious issues to overcome on how to store the methane, and some minor ones on plumbing the tubing.  I am good friends with the head of our village’s waste treatment plant and he is keen to see this project work.  Had him over for a beer as I put the last of the mulch on, we have some ideas that appear workable.  We do have some time – it will take about a week for the pile to hit peak temp and a few more days to heat the water in the drums.  Then we add the slurry, plumb in some tubing to take away the methane, start taking temp readings, and put up the “No Smoking!” signs.

“The time has come to do Epic Shit!”

Help fund the Methane Midden: Pledge to my Kickstarter project!

Be the Change!

-Rob

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Jean Pain Compost – Mulch Soak

Its been about a week since I picked up the 8 cu yards of mulch from the municipal yard with BART.  The grabbing of the mulch was almost instinctual, but over the past week some planning has set in as I need to be more methodical if I am to run a true Proof of Concept, let alone produce several dozen cubic meters of highly combustible methane gas within 20 feet of my home.  But first, lets catch up on the past week.

 

140 degrees in less than a week - total prep? Pushing the "up" button on the dump truck...

 

A few on lookers had expressed concern about the ability of pure pine tree waste to decompose.  That made me pause for a day or two- would the acidity funk with the microbial mix?  What about the resins?  No worries though, the pile steadily warmed and within 5 days was roaring away with steam drifting off each morning.  Took a temp reading today and it was well over 140 in many spots, and the entire center was over 135.  Hmmm… 4000#’s of material at 135 degrees.  Yep, that should be more than enough bTU’s for the project!

There are several really unique things that Jean Pain did in his methods, most of which I will try to capture.  First – he used brush.  At first glance, wood chips seem to be way to high in carbon.  But I have seen mulch piles heat up on numerous occasions, but they don’t stay hot long once they burn through their nitrogen.  Jean’s stayed over 100 degrees for 18 months!  A careful watching of the You Tube vids and readings of his book show a key point – he used GREEN, leafy brush.  Green brush has a ton of nitrogen and sugar rich sap, and the pile of pine I snagged was predominately green in color – i.e. lots of nitrogen.

Second, Jean soaked his piles for 2 days in a giant ditch.  Here is the what I am convinced this does and why it is so vital in his technique: the wood chips literally saturate themselves with water over the course of the 2 days.  This provides a store of water for the pile to keep the bacteria from getting thirsty for literally months on end, but does not force the pile anaerobic due to the large particle size of the chips; the bridging allows for enough air to circulate.  The bacteria live on the edge of the chips, and as they consume the water, more is leached from the interior of the chips through capillary action.   From what I can tell, when Mother Earth News did their expirements on his methods in 1980, they skipped this step.  I believe that to have been a fatal flaw, and one I do not wish to make. But how the hell do you soak 200 cu feet of mulch? With giant plastic totes of course!

 

I bought these last year off of Craigslist. Why? They were $25 each and just HAD to be good for something!

 

These totes are HUGE – about 54″ cubed- and they hold over 2 cu yards  or 350 gallons.  I bought 7 last year on a whim, and gave 2 to a friend in exchange for the use of his pole barn to store them in and a clearwater 300gph pump from harbor freight for my Appleseed BD Processor.  I love my life.  Anyhow, I figured  that 3 of these would be about perfect to fill with chips and water and let them sit for a few days to soak up all the goodness while I do some other projects like planting the 500 sweet potato slips that showed up last week.  It took about 3 hours for my “intern” Kevin and I to get them from storage, drag them to the backyard, and fill them up.  I also filled 3 of the 55 gallon drums I also bought last year for the biodeisel project.  2 of them will be the batch digesters, but I am getting ahead of my self.

 

2 of the 3 totes filled, along with 2 drums in the foreground. I have planted a bit more than my neighbors...

 

Luckily before we began to fill them I had an epiphany as to how to drain them.  Tipping on of these bad boys will NOT be an option once they are full of water, and even drained I think we will need some fancy levers and my 3 ton jack.   My solution?  I put the garden hose all the way to the bottom of the tote and filled them up as we schlepped mulch in.  Once the water reached the rim, I unscrewed the hose from the house and hung the female end over a bend in the gutter about 7′ up.  This preserves the water in the hose and will allow me to siphon out the water on Friday.  If it works, it will be brilliant!

Next steps will be leveling the 100 odd sq ft needed for the Jean Pain mini digester compost pile.  My plans there are to wall in the entire pile with 2-3 tiers of straw bales with the two drums in the center of a 9 x 12 rectangle.  The straw will provide a (relatively) unobtrusive structure for the neighbors and, once staked, enough support to contain the pile.  Also, I am hoping that the extra insulation will be an added benefit.  Still sourcing hose to wrap the drums with to regulate their temperature, and I have another friend looking into pumps.  After than I will need to rig up the drum lids with some barb fittings and hoses to pull off the methane gas.  And then finally, the big unknown is the methane storage.  Several options in the hopper- Jean used tire inner tubes, but not sure how OSHA would view that.  Kids play in my backyard…  Safety is a BIG concern.

Should have a post up later this week showing the completed pile, and will likely fill the drums either Friday or next week. Also, this thing needs a better name than the “Jean Pain Compost Methane Batch Digester Proof of Concept”.

I’ve always liked alliteration…

Enter the “Methane Midden

-Rob

Jean Pain Compost Methods – It Begins.

I’ve posted before about my infatuation with Jean Pain’s work and my desire to try to recreate his experiments here in Wisconsin.   Actually, when you break it down its a no brainer – I love compost and coppicing, plus I get to use chain saws, massive chippers dump trucks, and skid steers.  Given the chance, I would coppice and chop up trees and pile the chips on my days off for free, the fact that I get  methane, hot water and tons of compost out of the deal is icing on the cake!

Despite its awesomeness, this has been a “backburner” project for me.  We did a test run a few weeks ago at the farm -coppicing 25 3″ trunk diameter box elders and running them through my Bio-80 chipper.  The goal was to make a yard or so of fresh chips for use as mushroom growing medium.  As the whole, green trees went through the chipper the end product was fantastic – finely diced/shredded with tons of green material from the sap and leaves.  Unfotunately after about 2-3 hours of work, we had about 21 cu ft of chips (.6 cu yards).  From 25 trees.  Oi.  Jean Pain’s piles were 50 ton, or about 100 cu yards.   It would take a week to make a pile big enough –even if we could get the trees.  Of course we could rent a bigger chipper, but with all the farming going on, the idea got shelved.  Until today.

 

The bed holds 10 cu yards - I took about 7-8. See that steam? And it had only been sitting for less than a day!

 

I check my village’s mulch pile with the same frequency most men check baseball stats – for 2 weeks now it has been completely out – but yesterday or this morning someone dropped off about 12 cu yards of fresh ground young pine tree.   Just driving up I could see how many needles were left – the pile was virtually green.  BINGO!  While there was no way I had time to cut and grind up 500 box elders, I could spend an hour forking 7 yards into B.A.R.T.  I *knew* there was a reason I skipped the gym today!

As we are looking to do a major expansion (+500%)of our home gardens this month, I will need a significant amount of compost this fall – so despite living in an HOA I trundled my load of green gold home and proceeded to make a massive pile on the driveway.  Once finished cooking, this should be about 1500#’s of compost.  The fact that I already had a 3 yard pile of mulch chips already on the driveway only adds to the head shaking by the neighbors.  If they only knew what I had in store!

 

I just grin ear to ear every time I think about the neighbors...

 

What do I have in store?  I want to build a Proof of Concept for a smaller scale Jean Pain compost system.  I want to produce burnable methane, hot water, and humus from chipped green brush material.   To do this I intend to get 4 55 gallon drums that I have at the farm.  these drums have clamp on tops which will make filling them with a digestible slurry easy.  I will place these in the center of a 10’x10′ area and fill them half or so full with the brush and the rest with water -need to read up on that more.  Around the barrels I will wrap tubing, which I will then spiral through the brush material as I pile it up around the barrels about 3′ wide on all sides.   This will allow the cold water to cool the barrels down as the pile will likely hit 140 degrees, but methane bacteria prefer 85-105 degrees.  The area will likely be penned in with some garden or snow fencing.  Onto the barrels I will plumb in some tubing bungs to allow the methane to vent off.  I will then collect the methane in …. something.  I will be scrounging U-Line and other sources for large plastic bags – enough to hold 2-3 cu meters or I will make my own out of plastic sheeting.  I would LOVE to find a spark proof compressor to allow for storage in propane tanks, but if not I will likely just flare it off.  The goal here is to prove that I can produce ignitable methane, not if I can store it or run engines on it.  (that said, I have dreams of converting an old lawn tractor to run on methane and use a gas grill propane tank to power it).   In the spirit of simplicity, for starters I will use city water to cool the drums and will take temp readings from the water on the end to track heating capacity.  If things go well and I need alot of cooling (I do NOT want to keep a hose running all the time!), I may plumb in a 300 gallon storage tank and convert an old truck radiator for a heat exchanger to create a closed loop space heating system.  But I am getting ahead of myself…  My goal is to produce burnable methane, in my backyard, with no fancy gizmos.  Growing Power built a methane digester and theirs cost $750,000.  I am shooting for about $250 and that is only if I do my heat exchanger idea.  Of course, my scale is wicked smaller.

I have a uber steep learning curve on methane  (Dammit Jim! I’m a potato farmer not a renewable energy technician!) so I am using a life line.  See, one of my good friends just happens to run the village’s sewer plant and knows rather a bit about producing methane.    Luckily I have the first round of spuds in the ground and have a few weeks of relative calm.  Tomorrow and Friday I will be clearing the 10×10 area, bringing the drums down and soaking the chips.

It begins.

Be the Change!

-Rob

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