Making Torrefied Wood

I have been making torrified for a while.
Its easy to spot a chunk of the stuff.
We are all accustomed to seeing the cracks that form in the grain as it dries.
But when you heat it to the point that we cook the locked in water out you see these cracks get larger.

Its basicly smoked wood HA HA!

You know I just had a short back yard fire with the wife and this is what we fuel it .
Mostly charcoal at the bottom of my wash machine tube ( 1/4 full ) with pyrolized wood on top.
Wonderful stuff.
Very little smoke, and the flames are translucent yellow about twice as high as normal.
Closer to the fuel bed blue flames from the CO combustion higher up in the flame the hydrogen is burning out as the cellulose is finally consumed…
Very intense and high temperatures.

Doug Williams once talked about this on the old woodgas list.
He said torification would drive out most the locked in moister that regular drying could not.
In the process the wood itself would be changed into fuel that retained more of its original energy content than charcoal.
Another interesting point he made is you never can get wood normally dry enough that it still does not contain an excess amount of water.
Some of the water in the wood will be cooked out and cool the reaction zone in the water gas shift to help regulate temperatures but its more than we need.

Torrifed wood makes great fuel, but its more trouble to make than charcoal because you have to watch you do not cook it too much and you still need a gasifier with a tar cracking hearth to use it.
No real advantage ( like burning premium in a car that only needs 85 octane )

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Method of roasting in 1863 well industrial

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Different method to obtain roasted wood

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Tom, in a way any condensing hopper makes torrefied wood. But the problem is it uses the woods energy to do so, wich effects gasification efficiancy. But if we can Move the torification process elsewere we gain efficiancy and therefore mileage. In theory.

Francois,thanks for the pics!

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I see a process that looks a lot like a " Coke Batter ".

I have often thought about it.
How to make a small unit cheaply for wood, but the problems are acid gasses corroding the steel and the carbon from the product soaking into the steel causing surface hardness and brittleness.

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You can do it if you make clean charcoal first. You won’t get there with wood though. And from experience earlier this afternoon, you won’t get there with wet charcoal. :slight_smile:

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Another interesting and very good video on coking.
There is a lot of interesting technical info we can learn from.
The fellow that made this film exchanged some email with me about a decade ago.
very nice man, I hope he is well and still active.

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Well, with the mineral coal we move away from the subject,
drawing from above of a model that I find simple extract for roasted wood.
So at the top left you have a water sprayer finally that the water turns into steam so that the wood opens its pores and dries to the heart without for now this burn, the fan at the top between the two modules, captures the steam of the wood store, and passes through a radiator of hot air temperature raised by a fireplace at its bottom, this smoke is carried in ignition by an electrical resistance giving a torch which rises the temperature of the wood for the roast and leaves by the hatch underneath, we know very well now imagine a function with probes and PLC to achieve a perfect operation by respecting the desired optimal temperatures.

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Francois; Thank you for posting the drawing. This is a batch making cooker, not a continuous operation, correct? This is how you would make roasted wood to use in a gasifier for making wood gas.? TomC

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Hey, Frocois, it occured to me. Have you got any information on charcoal manufacture in the old days? I know the Swedish book touches the subject but not too clearly.

If l get your picture right, it circulates superheated steam? Its the steam that actualy heats the wood? Thats smart. Easyer to control and imposible to ignite the wood like in injecting hot air.

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For product flow, it can be done manually or with a carpet

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yes, the two-function steam, the rise in temperature while opening the windows of the wood, but last, there must be a flame to treat the roasting of the wood which thanks to its moisture, must not start a combustion, a fair adjustment must be imposed to have a successful result.

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I don’t want to bury people under outside of topic info about coal.
However…

Coke making can not be all that different, making a multi cell battery that uses the heat from other cells in a continues process to high quality charcoal has got to be worth investigating further.
The loading ideas, make a pushed of some kind.

The end product of the battery is basically white charcoal that has been heated to such an extent the pulverized feed stock has become chunks again.
I am sure we can adapt some of this method.

I avoided Coke making like the plague in my steel mill career.
Now I wish I had spent more time there learing.

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Given the carcinogens involved in coking coal, you are probably very lucky to have gone without that experience.

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5 years towards pension for each 4 years service on the batteries.
Its a bargain with the devil some people were willing to make.

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Been part of those bargains before, with little upside, the lot of many working men…

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It basically the charcoal making concept. The materials and process are usually different. They both drive off impurities through heat.

The coke is denser and more consistent. Wood density varies by species this the resulting charcoal varies. Thus harder to control the process, more material and harder to do.

I think there swiss have a process for smelting steel without coke.

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Hello wallace,

For the coal of the earth, it pollutes three times more than the charcoal, the old mine workers with their respiratory problems at the end of their career and a life time below average, reminds us of the reality, the Children in China with coal-fired power plants pay a heavy tribute, they do like Western countries, it is moving towards nuclear energy in the future,
During ww2, my father not to go to the compulsory labor service in Germany, he worked in the coal mines 50 km from his home, with no good memories,
Currently, although the Germans have a program to limit CO2 emissions using coal as energy, but I do not know if this has been successful.
I am distant with the coal coke .

cordially

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Maybe @Chris can start a new topic for this so we can get back to see wood supply?

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They have cut down a lot of their black coal use, but have only reduced their lignite use by like 10%. They import black coal which is significantly less polluting then the brown coal (lignite) that they mine locally. They also tend to gloss over the fact they export a lot of electric made from the brown coal.

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