Ray,
I have some concerns about the charcoal box. The idea of using 5mm sheet metal was generated to allow for the quick transfer of heat. However I am not sure if it will hold up to multiple uses as the excessive heat projected from the furnace stands at about 500C -700C. What is your take? What metal can I use that can provide quick heat transfer, hold the weight of 86 cubic feet of wood.
I really need guidance here.
Ava Zim, according to http://www.biocharretort.com/ it takes 4 hours to 8 hours, from lighting to shutdown. Then more time to wait for things to cool down, at least overnight. I usually load my barrel retort slowly during several days (Iām retired.), and cover it with a big tub. Then, I check the hourly weather forecast for wind direction and wind speed and humidity. Usually, I ignite at sunrise, or shortly before, when the grass if any) is coated with dew. A load of small branches is turned to a glowing bed of charcoal in 1.5 hours. If I use larger logs in the 3" to 4" diameter, it will need to burn for an additional hour (total = 2.5 hours). Then, I can cover the barrel and wait until the next day, or I can simply dump 20 gallons of rainwater into the charcoal. Since the holes around the bottom edge of the barrel are covered with clay, the water stays in the barrel and puts out the fire completely. When I first ignite the load, I add lots of small thorny brush such as mesquite and huisache (sweet acacia) to insure a good load of char on the very top, which is what burns any smoke rising from the larger wood inside the barrel. (My two barrel system has one barrel on top which acts as a big chimney. I throw paper balls and acacia into that top barrel to really get things going.)
I usually try to find scrap metal or rely on used barrels that I can simply replace when they burn out. The problem I have with local scrapyards is that they cut everything up into little hunks. The Keystone Pipeline uses 36" diameter pipe that has a wall thickness ranging from a bit less that 1/2" to almost 3/4" depending on where they are going to use it. Many people on this forum have built a Wayne Keith unit using 12" pipeline with wall thickness greater than 1/4", and even then have to go to great effort to insure it doesnāt burn out in the area around the input air nozzles. One of my neighbors was digging up an old 12" pipeline and selling it for scrap. He cut a couple of them to short lengths for me.
If all I had was 5mm sheet, I would probably stitch weld some angle iron to it, in the form of a frame, and expect it to burn out. Then, being cheap, I would try to patch it for a few more burnsā¦ Iāve even bolted some patches over some holes that developed in my 55 gallon oil drums. Perhaps someone else will offer an opinion.
Somebody suggested that I use Stainless Steel for the charcoal box. It will not rust or corrode under high temperatures I was told. What are your views?
Stainless would be nice! Stainless steels are generally more expensive than carbon steels. In my experience, they are harder to cut, requiring a plasma cutter or a high speed cut-off wheel in an angle grinder. Tig welding requires stainless rod and plenty of Argon inert gas. Some builders on this forum use stainless steel suspended on chain as a grate, and burn holes in it with a plasma cutter. I use 9" stainless cooking pots in the bottom half of my TLUD charcoal making stoves, but also use pieces of used steel stove pipe as sacrificial liners. Iāve gone though lots of liners, but never the stainless pot. Iām always on the look out for stainless scrap, but it is hard to find.
I always check the pots and pans aisle at the Goodwill for large dia and heavy SST items
Hello Ava,
I believe there are some āstainless steelsā that will rust depending on the chromium content. I found this out working QA at Bombardier. I also found this on line. It seems high temps aggravate the condition.
Pepe
I know itās a thread from 8 years ago, but wondering if this project and idea were developed
Not this guys concepts, no.
But some documented works done with DIY larger scale charcoal making systems with the goal to turn scrape hardwoods into a sellable product.
The best tips on this were by engineer Kristijan Leitinger, rural Slovenia.
Use the magnifying glass search tool in the top of page search bar for his 3-4, Kurst charcoal kiln topics April 2021 and August 2023.
Confirms all of the advices given above about emitted gasses phases. The process Heat generated with a slow beginning energy release. With a later almost impossible to control āGone nuclearā heat flaring off later.
The burn out thinning metals problems. Requiring systems wall replacement. The movable door warpage issues.
And Kristijan as rural located was not trying for an Urban no-see absolutely no-smoke.
Not trying for off-board heat farming. Just that his system had to only self heat without using massive amount of wastes fuels like motor oils or bought out LPG.
The conclusion can only be make charcoal out Rural. Using inexpensive scrap metals, and earth components. That will give the costs down to be able to make money on the finished graded made charcoal.
An in-use Urban system needing absolutely no-smoke and having to meet inspections for health&safety will be a money pit you throw your efforts into. Then only really a system to dispose of Urban generated wastes, money subsidized for that limited purpose. Any actually wood charcoal made will never offset cost of operation.
And whose activities can be shut down by any complainer. Not fantasy this. Fact.
Portland Oregon in the last 30 years.
First they shut down a lead acid battery recycling plant. It used the ground up plastic and rubber cases as fuels to melt smelt the ground up lead plated for recasting and reclaiming. Improved; then improved again emission scrubbers could not keep chasing the more and more restrictive PPM emissions flue gasses standards.
Next two diffnert 70 and 80 years old custom colored glass manufacturers. Artist and artisan glass makers Those same PPM emissions testing standards kept running up the cost to try and scrub out the metallics and rare earths used to color the melted to be formed glasses. Restricted. Then restricted again until ran out of businesses.
And now small local family restaurants being shut down for any detectable cooking oder smells from their venting blowers from their kitchens. New law. New way for any complainers to shut them down.
Ha! So small wonder the become popular portable on-wheels food-carts cooking operations, eh? You complain? We go.
The very same complainers still get the foods they love. Turning the providers into come-then, go-away somewhere else Gypses.
Urbanās in general are the worst with the Cake-Eaters mentalities. Lost all connections to true cycle costs for anything and everything. Just as long as all of the downsides of suppling all of their āneedsā are done somewhere else . . . like China . . . or Africa. Sure. Sure. Hands wring. And cry. Then pig out on more white meat chicken nuggets.
Steve Unruh
Use the pylolysis gas from the retort its self. I can ;produce enough gas for its own heat. Use the fire box to get it giong and use gargage wood for that. You making it way more complicated that it needs to be.
This is a very efficient retort it can produce its own gas for process heat. Add a second stack and its a two stage with a kiln. Over the summer I had my unit removing 15 lbs of water! Thats a lot of water that the machine doesnt have to use to get rid of any more. I only burn maybe 20 lbs of scrapp wood to get this thing going now and then it produces its own gas. If you are not carefull that thing will melt a hole in the earth.
Thanks for the response and video, Matt. Iām not sure if youāre addressing me or someone else, but no problem. I understand that your kiln produces enough gas to support itself, once it gets going from other fuel wood. But just for clarification, are you also saying there would be surplus energy/heat that allows for using gas for something else, too - like an appliance, for example? Or just the right amount to support itself until charcoal is fully made? Thank you
Yeah if you can figure out how to do it safely. I use the proto to heat the shop, but you must never ever leave this un attended as it can going to run away mode.
This year I added the second stage. I havent done video but its basically the same thing just stacked. The top is a dryer and its waste heat anywasy so might as well use it and that is perfect and easy.
Like a lot things with excess its a matter is it worth the effort to extract that waste.
A hot water coil wrapped around the bottom should would be a great way to produce hot water.
Thank you for the elaborate response and for pointing me to that thread, Steve. And yes I agree that regulation is made to serve the interests of the few, and weāre often not part of those āfewā.
So on the technical aspect of things, if I understood correctly:
All this confirms that the process energy fluctuates enough to cause surplus heat - which can be damaging to the setup, possibly causing a meltdown - and therefore one needs to also plan on distilling those surplus gases, or choose to flare to the atmosphere
And in an urban environment, it would require max condensing, max efficiency, max heat exchange, etc. in order prevent any undesired smoke, not even water vapor (because some people mistake white smoke for something bad, while itās just moisture).
We pretty much knew all that, but also very grateful for people like Kristian who demonstrated them.
This will sound stupid: I suppose I was tricked (or tricked myself) by the title of this thread. I thought this was about integrating the output of a gasifier into the working of a pyrolyser with some sort of smooth operation taking place between the two, allowing the mitigation of factors you mentioned, especially the non desirable effects. Iāve operated a gasifier before, and possibly dozens of pyrolizers that recirculate the gases for cleanest burn and most yield, along with condensation in some cases. It was worth a shot checking if someone used a standalone gasifier and a strandalone pyrolizer together for some sort of fully integrated manner that provides high quality gas/charcoal at highest efficiency and cost. Like I said, not exactly realistic or practicalā¦I guess. Blame it on the constant pursuit of better things
So run-away mode is when the system overshoots and things get very exothermic and you end up with very elevated temperatures? So is that your clue for diverting gas to an appliance until that gas is needed again for the system to sustain as it returns from overshoot mode back to nominal? I guess Iām trying to understand if itās permanently fueling an appliance, or an automatic function that diverts excess energy to the appliance, or just a manual procedure where you just open and close valves for running or shutting down the appliance based on observations and experience?
I hope my incessant questions are not driving you crazyā¦and thanks in advance
No you need that gas for your retort. There isnt excess gas only heat
Tarek, the closest I can come up with is the way those of us driving daily on wood harvest charcoal. Best guesstimation is I harvest 5% the volume of raw wood I run through the gasifiers in avarage. So, for every 20 bags of raw wood I consume driving, I get one bag of already engine grade charcoal as a by-product. Ash and dust need to be screened out though.
Iāve returned most of this bio char to mother nature over the years, but still have plenty stored. I havenāt found time or motivation to fabricate a charcoal gasifier yet, but itās on my list.
Ok thank you. I see now what you meant. I was hoping you meant that temperature was maintained at a a quasi-constant by diverting a portion of the gas to a secondary/auxiliary use. But all good now.
You control the gas output of the retort by adjusting the air intake of the fire box. Gas output of the retort will follow the temperature you let it run at. But too cold it will crash, so there is small learning curve but you will get it.
