Meat grinder for crushing biochar-NO

I had tried the meat grinder as an early attempt to figure out how to crush biochar. It ground a little bit of biochar with tremendous effort. What I didn't realize until now was that it destroyed the meat grinder.  I literally couldn't get it apart afterwards.  I threw it into metal recycling.    I had to go out and buy another one.  I wouldn't try it if I were you.  Learn from my failed experiment.

John S
PDX OR

Thanks John. I appreciate these kind of posts more than anything else on here. Happy Friday!

Gentlemen, I haver used two machines to make powdered charcoal. The first was a leaf shredder with a 5 hp gas motor.  Does a good job but makes a hugh cloud of charcoal dust that seems to get it to everythiung. The second one is a small electric powered cement mixer with a dozen fist size stones thrown in when I run it.  This has worked extremely well with a bucket place over the opoening.  It does a decent job of keeping the dust in the mixer.  In both cases we used a 1/4" hardware cloth screen to seperate out the not thoroughly burned chunks.  The pulverized charcaol then goers into 55 gal drums for charging.

If the charcoal chunks coming out of the retort seem too big, we first run it through the shredder for a short run to reduce the size and then put into the mixer.

Hope this helps.

Sounds like a great solution, Steve.  I put the char in between panels of plywood and drive over it.  I think if we let people know about some good solutions, many people will be able to do these activities well, who couldn't before.

John S
PDX OR

I give it all a long, long soak in stinky inoculant first.

When it's fully soaked, it crushes smaller with relative ease. Not powder, but I don't care about perfection. It works.

Thanks for your kind words. I certainly hope that it helps others and encourages them to try.  We live in Northern lower Michigan and the soil here is a thin layer of topsoil over sand with some gravel and rocks - you get one year of mediocre yields and then nothing. We scraped off the top soil and built raised beds with a hegel kulture base (using the cleared "junk" trees) topped by the reclaimed top soil augmented with precharged biochar and it has increase our yields many times over.  Well worth all the work.

Steve-
You should post here more often. People need to hear what you're doing. I'm sure there are other people who were in your situation and they tried and just gave up.  With the way things are going, we need to help people out.
John S
PDX OR

^^ What John said!

Douglas-
I have to admit that I am fascinated by your sequence on the inoculation first and crushing second.  What do you put it in to crush it afterwards?

Thanks,
John S
PDX OR

I would be happy to go through our whole biochar process from beginning to end if you think it might help others to do it.

I guess the question is "how detail;ed do I need to be"?  Wouldn't it just be a regurgitation of earlier posts?  There are, afterall, really only two methods of charcoal making and they have both been around for forever.

If what you're doing is similar to what others are doing, you could just chime in on others' threads and share your different methods.  It seems like you've got some good ideas that might really help people to grow stuff better and then they could feed their families better and feel better about themselves.  Make the planet work better too.

John S
PDX OR

Steve Welch wrote:I would be happy to go through our whole biochar process from beginning to end if you think it might help others to do it.

I guess the question is "how detail;ed do I need to be"?  Wouldn't it just be a regurgitation of earlier posts?  There are, afterall, really only two methods of charcoal making and they have both been around for forever.

If you break down your process, people will gain a detail or two, and maybe that will spark a new method. So don't be shy. Lay it on us. We have learned not to be arrogant -- there is always more to learn.

Steve Welch wrote:I would be happy to go through our whole biochar process from beginning to end if you think it might help others to do it.

Welcome to Permies, Steve!
Two things:
1. You might describe exactly the system someone else uses, but if you use different words, it might help someone understand it from a different perspective that makes more sense to them. We all learn different ways - I can remember a very competent teacher explaining a math principle in middle school 2 years in a row and feeling like he was speaking Greek both years. He had a sick day and the school secretary came and explained the same concept using very different words and examples and I understood it clearly! (she had clearly missed her calling)

2. Some people *really* need to hear about new things from more than one person before they believe it will make a difference. *Particularly* if the new voice is from an ecosystem more like their own. As John S said - if your description of how to help your land/ecosystem provide food helps even one other person grow sustainably for their family, you have helped the planet! I live with "glacial till" but at least I've got some clay and sand in with all those rocks! But I too, have gone to raised beds with lots of punky wood at the bottom and I'm only making small quantities of char which I generally add to my composts, but I'm starting to experiment with "weed tea", so maybe I should try adding some biochar when I'm making that?

However, I wonder if Hubby would let me use his cement mixer...

Great suggestions.  When I get a block of time I will relate the whole saga with the stages we went through to end up with our current process.  When we do our nexr run I will try to take enough pictures to show what we do at each stage.

I have been scratching my head myself for some kind of rough chop/grind device for my garden purposes. I haven't figured out what that might look like of course but I'm still pondering!

I am still in the infancy of developing a good way of producing biochar on my property but with even the most basic of pit burning followed by water dousing I don't want my biochar too fine! I am going to attempt to get a decent size round of wood and carve into it a bit of a mortar sharp. It is my plan to look like a lunatic with a giant pestle crushing up biochar to then soak in whatever swamp juice concoction that I have created.

John Suavecito wrote:Douglas-
I have to admit that I am fascinated by your sequence on the inoculation first and crushing second.  What do you put it in to crush it afterwards?

I use an Armstrong crusher.

If it's a high quality, low ash char and I want it quite fine, I put small quantities in a old metal snow scoop (scrounged) sitting on a picnic table (scrounged) and use the back of a shovel or spade (probably scrounged) as the crusher. Aided by muscle and bodyweight.

If it's "pit run" from the brush burning pile, which has more ash, it goes into an old heavy duty contractor's concrete wheelbarrow (scrounged) for the soak and then I chop vertically with a heavy spade, sometimes crushing the oversize pieces on the back or front (which conveniently has a thin film of strong concrete, so the char doesn't slip around). Usually this stuff is mixed with other malodourous muck and broadcast in the raspberries or around trees. They like it very much.

Sounds like it will keep your Arms Strong.

John S
PDX OR

Those little 2 stroke (or electric) tillers really move fast and chop soil up fine.  I wonder if you could confine your dampened char in a small frame similar to a raised bed and run the tiller through it a few times.  

Gray Henon wrote:Those little 2 stroke (or electric) tillers really move fast and chop soil up fine.  I wonder if you could confine your dampened char in a small frame similar to a raised bed and run the tiller through it a few times.  

I thought about this. I've got a 4-stroke Mantis tiller.

However, I don't worry too much about the char being coarse. As long as it's kept wet, the freeze expansion of a Canadian prairie winter will do the finish work for me.

Douglas,

I am envious of your strongarm approach to pulverizing your charcoal and fascintated that you prefer to do it when it is still wet.  Our experience, when open burning and quenching, was that the charcoal was very difficult to reduce when it was wet.  Mostly because the burn was rarely thorough enough to turn all of the wood to charcoal. We ussually opted for waiting until it dried out.  What's your secret?

Steve Welch wrote:Our experience, when open burning and quenching, was that the charcoal was very difficult to reduce when it was wet.  Mostly because the burn was rarely thorough enough to turn all of the wood to charcoal. We ussually opted for waiting until it dried out.  What's your secret?

Steve, there is no secret involved. I'm using the lazy-ass, high volume, low effort method. My char from open burns is a bonus -- most of my neighbours burn it down to ashes. I'm planting the seed of an idea on that front.

But if you plan to harvest char, it's crucial to let it cook down fully. This takes a bit of effort and management. In an open burn, you're going to have a fair amount of loss to ash. Which is fine -- fresh, clean ash has many uses.

But keep stirring and working that pile -- just enough oxygen to burn off the volatiles, but packed down enough that it doesn't all turn to ash. Sometimes, when headed for bed, I use a an old lid from a portable firepit (scrounged), toss it on the glowing coals, stomp it down, and pack the edges with sand/soil/snow or whatever to form a rough seal. It might keep cooking for days, even at -35C. I actually packed two feet of snow on a pile last year, stomped it down with my big boots, and found it burning through three days later.

Moral of the story: don't rush the process.

Steve,
There is a timing pattern to this process. I burn in a 55 gallon barrel, so it is easier for me to time.  I have found empirically that when the flames are only 5-8 inches above the wood, generally after about an hour and a half, it's time to douse it.  Dousing it puffs it up so that there is more space inside the biochar, and therefore more hotels for the microbes.  When I crush it, only about 2 small pieces have wood in them out of a full 55 gallon barrel and then some. Also, there is almost no ash.  The timing will be a little different in an open fire, but lots of people on this forum use that method, so they might be able to chime in more specifically.  If you are still getting a lot of wood or ash in your burn, there is definitely room for improvement.  

JohN S
PDX OR

John,  We have abandonned open burning  except for the large cleared trees that aren't good for lumber and end up as hugel kulture garden bed bases.  Our experience with open burn was frustrating because to get it right took a lot of attention.  We learned that the best open burns were with stock that was all about the same size. And, for reasons I haven't figured out, the best burns are from the top down, not from the bottom up.

Today we use 55 gallon drums with 8 inch dirameter, 5 foot long chimneys.  Inside the barrels we use 35-40 gallon drums as retorts with tight fitting lids and holes in the bottoms which allows the off gassing compounds to contribute to the heat of the burn.  Like a good RMH, the exhaust is clear and clean - absolutely no smoke once it gets going.

In a couple of weeks when we get back to the farm I will  post some pictures that will, hopefully, paint a clearter picture.

Yes, it appears to me that many on this list use the trench method, but not as many just use an open burning pile.  I think that crushing and inoculation in place sounds easier with the trench method, of the two.   I do TLUD 55 gallon barrel, but no retort. It seemed to difficult to make enough biochar with a retort, and I didn't know how long the retort box would last.  Everybody has to adapt biochar to their particular situation.

JohN S
PDX OR

Agreed, the situation is different for all.

I suppose it's important to define whether making char is the primary goal, or a byproduct of other activities.

I'm sure Steve's kiln method produces very high quality char. I'll be interested to hear of the labour inputs required to set up each burn.

I'm perhaps in a different situation -- I have a small mountain of woody material that must be collected and disposed of for wildfire control reasons. I can hardly keep up. The lowest labour route is a single giant pile, burned down to ash. However, a little bit of management goes a long way. I arrange the wood pile in a long line. As the burn progresses, good coals can be raked onto a separate pile and cooked further in a more controlled way. And, if the feedstock is fairly straight and uniform, I'll burn it in my semi-open barrel kiln (made-up term), which produces much better results. But still, char is a byproduct of the primary task.