Bob Lewis

I'm just starting to make biochar in 45 gallon drum retort.
I've been directing all the gasses back into the fire to heat the wood but now I'm reading about wood vinegar.
I've seen a commercial operation and how the vinegar is condensed out of the smoke before other gasses go on to feed the fire.

My first question - how much wood vinegar is produced per given volume of biochar?
I'm burning mostly poplar saplings under 3" and tag alder branches about the same size.

More questions will follow.

Justin - which province are you in?
I've been thinking king along similar lines.
I made a char cooker out of a 45 gal barrel and some steel doors, using the gasses to finish the process.
When I saw how much heat was coming off it, I thought I should be making g mybiochar in winter when the heat could be usedas well as the biochar.

I'm currently thinking of a greenhouse with a (rocket?) Biochar stove that I would run on the colder nights.

Hoping to have time this winter to work on the design.

Ask the ceramics guy to give you different rated cones to test.
They re like incense cones and at certain temps they bend or break.

Start with low temp ones maybe in different places in the barrel.

It would be good for you to know as well. There's a sweet spot for the best biochar and I think I read that it's about 700F much higher than that gives poorer quality.

I've just started to learn about it.
I'd like to find an affordable way to build one that I could operateinside a greenhouse with 30 ft of chimney running through a rocketstyle bench to salvage virtually all of the heat, which is just a free byproduct of the biochar.
And I have much more free time in the winter for making it.

I think I didn't explain myself very well.
My bench is cobb.

I am suggesting that as I add layers of cob, that I will place cans or bottles full of wax in the cob between the pipes.

The wax will melt, absorbing a lot of heat just to melt it, without actually raising the temperature. When the cob is cooling, the wax will harden, releasing the heat that it took to melt it. I fill the containers about 80 % with melted wax. It will shrink as it solidifies. I've put it through a couple of melt/harden/melt cycles and the containers hold up fine. Should they leak, the wax will be contained within the cob.  It might absorb somewhat into the mud, but I don't think it's going to run out in a pool.

Has anyone tried phase change materials in the bench?

I have a lot of dirty paraffin wax. Melts at about 155F. I've been thinking of putting empty juice cans or masonjars of it between the pipes. It takes in a lot of heat to melt the wax and then gives it back slowly as it hardens.

That last post with the picture - I had made the barrel so the top was 2 inches above the chimney, but the top bowed up. I had wondered if that affected the efficiency - but also, my kettle didn't sit well on top, so we cut a 14 inch diameter hole and then welded a 16 inch diameter piece of 3/16 steel over it.

The pic below is what the bench looks like now.

Thanks to all who took the time to reply.
When I moved here, there was a 28 ft travel trailer - a 3 season trailer - single pain windows and maybe an inch of insulation. I added a 10ft x 26 ft room which has 4 inch urethane panels in the walls and ceiling. I also added those panels all the way around the travel trailer and a few inches into the ground, just to prevent any drafts - and then house wrap around everything. Built a roof over the trailer and addition with extra insulation above the trailer as well.

I knew the shack was not the best, and I wasn't expecting round the clock t-shirt comfort, but I thought the stove would do better than it was.
Thanks to you folks, I think I can expect better performance when the bench is completely dry. I have made the bench so that I can take off the end and extend the pipes another 3 ft - so that will add 6 ft of piping - but I might have trouble digging more clay and sand now, so that might have to wait for next year.

Last winter with a barrel stove was pretty rough - getting up every 3 hours to refill the stove and damp it down - was still only 15 to 20 F when I woke up. I've improved the insulation and draughts a bit this summer and built the rocket stove. I'm aware that the cabin could be greatly improved, but this is just a temporary home until I decide what and where to build.

Based on the suggestions, my cushions are now on a 9 ft x 3 ft x 3/4 inch OSB with 2x4 crosspieces underneath to allow some of the bench heat to escape into the room. The bench is built against the trailer wall, but I have now decided that I don't really need the trailer much, so I've closed it off for the winter.

Today - for the first time in a week, we have blue skies and full sun. The batteries are charging nicely, and my little greenhouse made from 5 old thermopane patio doors is up over 80F so the stove is off and the doorway to the greenhouse is open.

I"ve built my first rocket stove mass heater a few (3?) weeks ago. I have a few questions...

Creosote etc burns off at approx. 1000F - what temps should I be seeing on the top of my drum that would indicate that I'm getting hot enough to burn off the creosote?

the bench was built up over about 10 days - layer by layer - with fires running all day with each layer. I have cushions on the bench now, and the bench gets up over 100F under the cushions. I sleep on the bench the past few nights - it's great - but with outside temps down to about 15F, I wake up to about 40F room temp. I'm running the stove about 12 hours a dayl Does it just need more time to completely dry out the bench? I'm looking at minus 40F temps this winter, so I'm hoping the stove is going to get a lot more efficient. There is about 26 ft of 7 inch pipe in the bench, two 90 degree turns, and then the chimney goes  straight up through the roof about 3 inches behind the barrel.

I'm getting about 500 to 600F top center of the barrel most of the time, but I have had it up to about 1000F with the driest, smallest wood.

I love it, but it isn't living up to the ads for a 2 hour burn for round the clock warmth.

What do I need to do?

I've been wondering if wood ash from the stove would help to hold it together in the absence of clay. I have read that very fine (fly) ash can be used in place of part of Portland cement for concrete - .