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