Introducing the ARS-C - now everybody can make biochar

Introducing the Accidental Rocket Stove Inspired
Continuously Harvestable Biochar Pipe and Stove
Contraption or ARSICHBPSC for short and
ARS-C{pronounced arse{silent e}-c} for shortest.

In the past I have experimented with various components
like drainpipe, brick, biscuit tin, floor tile stacks
but they all suffered from capsizing{not a pleasant
experience}, smoking, extinguishing and all did not
permit you to pull out the glowing red embers as you
like.

I have learnt that a rocket stove requires an almost
airtight burn-intestine{for lack of a better word} to
function smoke free. For some stacks, the introduction
of a stove ring acts as a lifesaver and
reverse-afterburner by introducing much needed oxygen
to the combustion gases and sometimes I cut windows in
the biscuit tin for the same reason as well as help
create a vortex of sorts.

The flames are usually roaring ferocious and can reach
eyelevel. The reverse-afterburner helps cool{or maybe
not-I don't have a fancy thermal camera} the stack. The
heat produced is so great that {the drainpipe outgasses
and the biscuit tin glows red after carbonizing its
paintwork} I could even put in green sticks and it
would shortly burn. However the more successful this
is, the greater the pile of glowing embers at the
bottom which instantly uses up all the incoming oxygen
thus starving the rest of the rocket stack. When this
happens, the flame goes out. If you go for a pee and
return, you face a dark stack and relighting this is
always a bother since you are trying to introduce a
flame source into a heated carbon dioxide environment
and any fresh fuel/sticks will smoke horribly when you
drop it in.

And at the end all I get is a pile of white ash.

So after the final iteration of the ALL-B{I have added
to the post and it is worth a relook}, I thought I
would give this another go{also my wood pile and
combustibles was piling up} but with a bigger bore{it
just so happens that these are what I picked up by the
roadside}. And this two-piece stack immediately hit the
sweet spot hence the "Accidental". Toppling over is
reduced. The pipe will expand in use and will crack
longitudinally and this serves to allow a bit of air in
along the stack. The flames are not toweringly high.
Two half-pipes will also work and you can get a nice
vortex going.

This is best operated at twilight so you can see the
embers easily. If the ember you pull out smokes, you
can re-introduce it easily. I have done 3 burns and all
have been successful beyond expectations. The size of
the bore is the secret. It is wide enough that you can
have new-burn, mid-burn and end-burn fuel co-existing
without extinguishing the flame or creating smoke.

You need a metal spade, a metal saucepan, metal tongs
of different sizes, lighter and a fan. As the embers
drop down you use the tongs to harvest them and spade
them into the saucepan which holds some water. I cut
sticks longer than the diameter of the bore. Why? If it
is shorter, it could fall flat unto the bed of embers
thus somothering it by immediately outgassing and
making relighting the flame a very difficult prospect.
A slightly longer stick would only have one end in the
bed so the outgas from this end will be carried off and
ignited by the flames of the other fuel in mid-burn.

You can appreciate that for a smaller bore, the leeway
is much reduced and a bigger bore might not contain the
flame enough to ignite the gas produced at the far
side of the bore.

For the ARS-C, the Goldilocks number is 6 inches for
the bore, 21 inches for the overall height of the burn
chamber and 3 x 3 inches for the harvest window.

If you have cob on hand, this would be a nice weekend
project. You can experiment with air injector ports at
various heights and arrange them to form a vortex, etc.
Always remember that fire is a living thing and it
takes experience to have a sustained rocket style burn.

Always pee before main engine start.

I keep a fan handy to cool off as well as to assist in
the ignition.

Remember that this is not a rocket stove. This demands
a fast burn for maximum throughput of biochar.
Harvesting all the heat released is another project
altogether. EG suspending a metal container filled with
HDPE{milk container material} plastic to melt into
blobs which can be shaped into things like paving
blocks. Or drying green wood.

I am sorry this comes at the wrong time since those
along the West Coast already have many lifetimes worth
of biochar at their doorstep.

This is intriguing.  I am having trouble completely wrapping my head around it.  I think I"ll have to come back in a few days when I'm more refreshed.
John S
PDX OR

I've been wondering for some time if there was an efficient way to make biochar using a rocket stove as the "power" source, so I read this with interest.

It would be really helpful though if you somehow post the picture with parts labelled? I'm not even sure where you are putting the wood in for example. There's a lot of "stuff" in the picture and I think most isn't part of your set-up, but I'm not sure. Some simple diagrams might help a lot.

Either way, I'm glad you're making biochar. I was making a poor version by putting some bits of wood and bone in old cans in our wood stove and building a fire around them. It wasn't perfect, but I've got a stock-pile of it that I'm adding to my compost pile as I layer it to activate it and hopefully to help improve and lighten my clay soil. I want to do more though as it seems it's a good way if you've got a lot of extra woody material that is a forest fire hazard if not dealt with, to use it to sequester carbon.

Jay Angler wrote:
It would be really helpful though if you somehow post the picture with parts labelled? I'm not even sure where you are putting the wood in for example. There's a lot of "stuff" in the picture and I think most isn't part of your set-up, but I'm not sure. Some simple diagrams might help a lot.

Thanks for the critique. I did mention that{as seen in the picture} that you pull out the embers with tongs and if any smoke, you could introduce that back for another go. This implies that the ARS-C is top loading. I apologize if this was not explicit. So, you harvest as you go and load fresh fuel at the same time. Just enough to keep the burn rate going and it is very forgiving. This version is a two-piece unit comprising a charcoal stove and a clay pipe placed atop. In my yet-to-be-approved edit, I suggest how you can make a single-piece metal version plus a lazy way to inoculate the biochar. Any fresh fuel dropped in will start to smoke. The height of the stack traps the smoke long enough for a flame to encounter it and ignite that thus making this almost smoke free. The trick is to keep the flame big enough to stretch across the bore. My prior attempts used a skinnier clay pipe. The flame easily stretched across the bore but any new stick would out-gas so profusely in that intense heat that this extinguished the flame. You have to look really hard to see the smoke and if that still bothers you, do this when it rains. Win-win. I know that my neighbours will not hesitate to complain. But this is the month of the Hungry Ghost Festival when they burn lots of effigies like paper Mercedes-Benz cars, mansions, servants and now face masks to give to their ancestors in the afterlife. Those create lots more smoke and ash. My ash comes from the paper used to start the fire. One good source of kindling is weather beaten exposed plywood. The sheets start curling and can easily be ripped off. When dry, these burn readily as long as you don't object to the type of glue used in the plywood. Dried banana leaves will burn readily but also produce copious amounts of ash that will unfortunately land on freshly washed car paintwork and trigger an international incident.

If you could somehow post a video of this from start to finish I would appreciate it.  This project looks like something everyone could do.

So far, it sounds harder to build than my set up, but easier to run.
John S
PDX OR

Edward Lye wrote:

This implies that the ARS-C is top loading. I apologize if this was not explicit.

Believe me - no apology necessary. When you are familiar with a task, it hard to know what will confuse someone who's only pathetic attempt at a supposedly idiot-proof rocket stove was some smoke and not fire! That's what is great about permies - I can ask people questions, and they fill in the pieces I missed. (Your comment that the larger diameter stack made it work more easily may be key!)

And wrote:

In my yet-to-be-approved edit, I suggest how you can make a single-piece metal version plus a lazy way to inoculate the biochar.

Don't worry about simply adding more on the subject as a new post. Personally, I've found that "metal" and "trying to make biochar" don't mix that well, because the high temperatures tend to put holes in the metal, so the fact you were using clay actually attracted me to your project. I've been considering the idea of making some sort of outdoors small rocket stove to experiment with out of clay, but we get so much rain in the winter, which is the only time we're allowed outdoor fire due to wildfire risks, that the concept hasn't moved further. If it could be used to make biochar, that would move it higher on my list for sure!

So yes, if you do more experimenting or take more pictures, we'd all be happy to see them!

Jay Angler wrote:

Personally, I've found that "metal" and "trying to make biochar" don't mix that well, because the high temperatures tend to put holes in the metal, so the fact you were using clay actually attracted me to your project.

I have always read that metal won't last long with biochar, but that hasn't been my experience so far. My metal 55 gallon drum has made about 15 biochars and doesn't seem to be wearing out.  It may be because it is TLUD and has a chimney, so the flames and heat are going up, rather than being contained.  Just a hypothesis.
John S
PDX OR

It took a while to check whether the battery/SD card/resolution
of the camera or smartphone could handle the entire burn.

Time needed also to collect enough fuel. So to address doubts,
answer questions yet to be asked, tips, techniques as
well as highlighting the DANGERS involved, may I present the
unscripted, unrehearsed, first take, single take, unedited,
unassisted by Industrial Light and Magic, cinema verite 43 minute
instructional video on how to make biochar with the ARS-C
and obtaining compost tea{NVBAL} to innoculate the biochar.

Enjoy.

 

PS1 I forgot what else I added to the edit which is stuck/not approved/dunno
   but making this out of an iron pipe is inadvisable simply because FEMA
   might mistake these versions as mortar launchers which it does unfortunately
   resemble. When separated, my stove and pipe attract no attention whatsoever
   until gazed upon by the acute senses of an astute exaptationer/exaptationist.

PS2 It turned out better than I expected. Yes - some wayward shots, lack of
   close-ups, no slo-mo effects, no car chase sequence, superhero 3-point
   landing and a CAUTION not to operate this if there is a breeze or significant
   wind.

PS3 Since I still find adults confessing to TLDR, this had to be marked
   Age Restricted to downregulate mishaps. I hope you understand that safety
   is important. As with all things, practice makes perfect. The ALL-B and ARS-C
   are independent but they complement each other. The only way to scale this
   it to have multiple units run concurrently. Maybe on a carousel.
   So far 4 good burns out of 4 attempts. May you have similar success.

Thanks for the detailed video. I think the process shows promise. It is actually rather similar to my TLUD in a 55 gallon barrel.  I think there will be many applications to many people's circumstances. Most of the people who I talk to here locally make small biochars like this.  For me, I need the 55 gallon size because I need the amount of biochar on a larger scale. The more options we can show people, the more people will be improving their soils, sequestering carbon, and improving the health of their produce and their bodies.

John S
PDX OR

One of the problem with biochar in TN, is we have a ton of moisture on everything?  We got just over 4 cm yesterday.  hum, 1.57 inches rain.

Yes, I think that for most people, planning your biochar burn around when you can get the material (wood, corn cobs, etc) dry is a key factor.  Right now it's summer and everything here is dry as a bone. That's why we have such epic forest fires.  However, in the spring and in the fall, I have to be very careful about preparing my wood and storing it under cover if it is going to rain.  In the winter, I don't burn biochar at all, because the days are so short and rainy, with virtually no evaporation.

When you burn wet wood , you get more smoke and less char: the opposite of my goal.

John S
PDX OR

Last month, 23Jul2022 and 28Jul2022 it rained 4 times. 22Jul2022 it rained 3 inches.

Someone threw away a crockpot bowl. I leave it out as a rain gauge. It tops out at 5 inches and when this is full, I don't know much rain we got.

If I want to dry/dehydrate anything I find a large container like a 5-gallon bucket fill it up and place a pane of glass over it. A binder clip or twig to provide a small gap for moisture to escape. Place this in the sun and neglect. An abandoned car is even better. Stuff things inside and let the sun bake them dry.

For stuff that is unsuitable for the ARS-C, I use a retort-brazier combo. Temperatures are high enough to melt those tyre balancing weights.

One thing about the ARS-C is the ability to switch "off" in about 5 minutes. The second thing is the high yield compared to the retort-brazier combo.  There is very little white ash left behind when you are finished.