Producing BioChar efficiently without the mess or effort

Hello,

I'm new here. I did a little research on the topic and saw a lot of conversations about BioChar, yet didn't see anything referring to people's preference on how they like to make it, or any preferences. I have been tinkering with "High Tech" methods. I'm an engineer that loves projects . So I want to get a few opinions on a device I am building. Currently, I'm building a microwave heated BioChar kiln. Although, I don't have a lot of experience making BioChar, I wanted to know a few things about people's experiences:

1. How much BioChar do you typically make at one time? In your opinion what is the perfect amount? Any other comments on capacity?
2. What is your favorite feed stock? or typical feedstock?
3. Would you like to have the option to use the BioOil (liquid fuel) or SynGas produced from the pyrolysis process? (maybe to produce heat, run an engine, etc)
4. Do you test your Char for quality?
5. Do you have a large feedstock of organic materials? If so, would you like to produce and sell Biochar?

Any help or information on your experiments would be helpful. As the project develops more I will post pictures and "How To". All my materials are "In Transit" and I'm getting excited.

1)  I normally make 10-15 gals or so at a time.  The perfect amount would be approx 1 ton, but I would settle for 500lbs
2)  I get pine board cutoffs from a local truss company.  They are free to anyone that wants to stop and load them, and are often available.
3)  I can't think of any reason why I wouldn't, especially if I could store it for use in a generator.
4)  No
5)  I would love to do that, but I don't have a steady enough supply of feedstock.

When I hear you say "high tech" methods, I immediately think "expensive".  While I think there is a market for biochar, I'm not sure how large a market there is for a machine that makes biochar, unless you come up with a way to make it cheap and efficient.  I personally can't see using electricity to make biochar, when I can make it by digging a hole in the ground, filling it with wood, and lighting it.  I think there are two kinds of people making biochar.  Companies with huge industrial machines that make it and ship it on semi's all over the place, thereby going against all the reasons I want to make or use biochar, and people like me that make it themselves for use themselves, and probably aren't willing to spend a lot of money on it.  The people that I know that are interested in making biochar are tinkerers that build their own kiln, mainly from found materials, and aren't really interested in high-tech methods of creating it.

1)  I make 2 gallons a day in a stock pot in my wood stove during the fall and spring when I don't need full loads in the wood stove.  
2)  Typical feed stock is cut up pallet wood chunks (heat treated of course)
3)  Since I'm doing it in the wood stove I'm already using the syngas to heat my house
4)  Wouldn't know how to test it.  Unless charred is good and brown is bad and then yes, I do a routine visual inspection
5)  I have plenty for my needs, probably plenty for Todd's needs as well.  Demolishing the pallets is more work than the char is worth (I assume) so I doubt I'll be going into the char business anytime soon.

Good luck with the machine and don't nuke yourself in the process

Thanks for feedback!

I'm looking at a few options for my device. A small home grow set up (5-10 gallons per cycle), a larger batch process (55-100 gal) and then Custom built sizes up to any size you want these can be batch or continuous feed processes. Also i could build a flush mounted heating device to be attached to what ever containers you have available (and included instructions so no one kills themselves).

As far as carbon foot print, my idea is for people to make their own biochar and use the fuels pyrolysis provides rather then packaging and shipping it all over the world. As far as expense goes these things will be cheap, roughly $100, $200, $custom, respectively.

Imagine cooking biochar in your microwave, exactly the same way as you heat up your lunch. 7-10 mins and your done, no holes to dig or fires to put out and you get both the liquid fuels (potency depends on HC content in feedstock) and Biochar. If i get a little more interest / feedback ill draw up my design and share it here. Its currently just a idea backed with plenty of research and some experimenting has been done but the process is cheap, feasible and simple.  

Chris Fraughton wrote:Thanks for feedback!

a larger batch process (55-100 gal)

$200,

7-10 mins and your done, no holes to dig or fires to put out and you get both the liquid fuels (potency depends on HC content in feedstock) and Biochar.

If you can do that, I'll be your first customer.

quite interesting.  I am fine with traditional means but if truly what you say I would entertain it.

I registered just so I could say, tell me more ...

Pyrolysis produces some nasties that are burned up in the normal process.
Some good stuff too, like wood vinegar
If the off gassed constitutes  are not condensed into bio-oil, where will they go?
Will you separate the flammable and the innert?

[quote
1. How much BioChar do you typically make at one time? In your opinion what is the perfect amount? Any other comments on capacity?
2. What is your favorite feed stock? or typical feedstock?
3. Would you like to have the option to use the BioOil (liquid fuel) or SynGas produced from the pyrolysis process? (maybe to produce heat, run an engine, etc)
4. Do you test your Char for quality?
5. Do you have a large feedstock of organic materials? If so, would you like to produce and sell Biochar?
]

I make a 55 gal drum full at a time.  the perfect amount is what ever you can make at any one time. Most gardeners would benefit from at least 50 lbs. per garden bed.
What ever I have as left overs that isn't treated wood. I also sift my smoker ashes for left behind charcoal.
I use a "still" type hat on the char maker that adds the oils to the flames.
Yes I do test the initial char prior to activating it with microorganisms, and again after activation to get an idea of the microbe counts.
I am not interested in going into the business of selling bio char, the few companies that already do this make start up costs quite a bit high for the first five year return on investment.

Redhawk

While not a "big" system, the efficient use of exhaust gases to fuel the fire seems quite appealing for the example shown at https://permies.com/t/19523/Charcoal-Bio-char-Production-Utilizing#281042 and at http://www.carbon-negative.us/burners/backtap.htm

I would think you could create a brick rocket stove, and attach a half barrel to the top of the riser, and sit some spacers on the top of the riser. You then insert a slightly smaller, sealed barrel holding the biochar materials into the half barrel, ensuring that the CSA isn't limited here using those spacers. There would be an exhaust tube coming out of the lid of your biochar container, and you run that down to an intake port that feeds into the very bottom of the heat riser. Once your starter fuel gets the retort to start off gassing, that exhaust feeds back into the burn tunnel and no more fuel needs to be used to keep it burning. Once all the gasses are used up, the fire will go out.

As mentioned in those links, there's excess gasses relative to what's needed to keep the system self-fueled. Perhaps the feed pipe could split, with a smaller diameter feed to the original burn tunnel, and a second line which feeds a second heat riser. You could have a second retort filled up and waiting, and light those gasses to start a second burn while the first one is running, but that seems to be getting complicated between 2 systems linked together and timing it. I think just getting the burn to self-fuel after the initial heating helps a bunch, especially if you can fill up a 55 gallon barrel with material.

You would need to size one barrel to fit inside the other without too much spacing between them for the hot gasses to help heat up the sides of the retort. Inserting a 55 gallon barrel (or whatever size you plan to use) into another barrel, even when empty, isn't going to be easy for everyone. Having something to stand on, or burying the burn tunnel underground can help. Then you can fill up the retort, attach the lid, and then attach the exhaust pipe to the heat riser. If buried, you would have that pipe coming up out of the ground and maybe it's level with the outer barrel lip, which would make the retort lid have a much shorter attached pipe that's easier to handle. After the burn you remove the barrel full of biochar, or empty the char out first depending on the weight.

This would be a stationary system, which is an obvious downside. But I can imagine you could make the outer barrel detachable, same as the retort, so you could cover the burn tunnel and it wouldn't be taking up space. You could also tip over the outer barrel while the retort is inside of it, to pour out the biochar and you could also insert the empty retort into the outer barrel while on its side, then lift them back into standing position (instead of picking the barrel up to head height). I think I would just have a portable cover or just a tarp though to protect it from the weather, and set it up out of the way myself. This seems like it could be an affordable setup which minimizes wood waste relative to the amount of biochar, all depending on the size of barrel you can use and get a full offgassing.