The Making of Wood Vinegar

Peter Singfield, posted to the Gasification Discussion list October, 2004.

One chemical industry that was ubiquitous in earlier times (1920’s) was the
wood distillation industry. The principle product, after processing, was a
charcoal with low yields of chemical products. The wood used for
distillation was air dried for 6 to 18 months. Artificial drying methods
were later developed to shorten the drying time and better control the
moisture content. During distillation, wood is placed inside an oven and
heating started. When wood is heated above 270C, it begins a process of
decomposition called carbonization. If air is absent, the final product is
charcoal (since there is no oxygen present to react with the wood). If air,
which contains oxygen is present, the wood will catch fire, and burn when
it reaches a temperature of 400-500C. The final product is wood ash. If
wood is heated while away from air, moisture is first driven off, and until
this is complete, the wood temperature remains at 100-110C. When the wood
is dry, its temperature rises to about 270C, it spontaneously decomposes,
and heat is emitted. This is the well-known reaction that takes place
during charcoal burning. The first distillate (condensation from the gases)
is almost entirely water and it is not until about the 4th hour that the
liquor slowly darkens and contains increasing amounts of acid. The crude
condensate produced from the distillation of wood is called Pyroligneous
Acid. The crude Pyroligneous Acid is then refined by fractional
distillation to separate a food grade version that is suitable for use in
health products.
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Outline of technology
We developed the furnace to recover the bamboo vinegar and bamboo charcoal
because there is an abundant bamboo resource in Kitakyushu City.
This furnace is provided with a gas burner for completely combustion under
the theoretical amount or less of air. Waste gas, which is generated in the
combustion furnace and does not contain oxygen, of lower temperatures in
the range of 250-300deg.C is cooled and the bamboo vinegar is collected.
Next day, the bamboo placed in the another drying furnace is heated rapidly
at high temperature without air and dried by distillation.
Bamboo vinegar and bamboo charcoal, both quality being good, can be
produced by these furnace.
Our company can offer the technology to obtain bamboo charcoal and pure
bamboo vinegar.

Characteristic and effect (including the system chart)
The bamboo charcoal and bamboo vinegar are conventionally produced in the
kiln made of soil. The bamboo placed in the soil kiln is burned and the air
is intercepted when the fire turns completely and then fire is extinguished
(The natural method). Consequently, the one-cycle needs 5 to 7 days to
produce them.

Our production flow is very simple so that the operating time to produce a
bamboo vinegar and a bamboo charcoal will end in a day.

Specification
1. Recovery flow of bamboo vinegar

bamboo is cut and

placed in the furnace
-> heat at about 250deg.C -> smoky volatile product -> heat exchanger ->
bamboo vinegar

Use example of bamboo charcoal: fuel, activated carbon, water-treatment
agent, soil conditioner, etc.

2. Producing flow of bamboo charcoal

the bamboo after recovering the bamboo vinegar is placed in the furnace.
-> ignition and naturally leavment -> carbonization -> interception of
air -> bamboo charcoal

Example of usage of bamboo vinegar: an activated agent for agriculture, a
deodorization, a raw material for medicine, a food, etc.
3. Producing method of wood vinegar, bamboo vinegar, and bamboo charcoal.

Woods or cutted bamboos are placed in the first furnace, in which the
material is heated at 200deg.C for 4 hours to adjust the water content of
raw material.
After the temperature of furnace is decreased, the material in plastron
basket is moved to the next carbonization furnace which is set up in the
neighbor and then heated at 850-100deg.C for 4-5 hours. Thus obtained
charcoal is a similar product obtained from soil kiln.
4. Outline schematic drawing of the furnace

Recovery furnace of bamboo vinegar

3. A photograph of the recovery furnace of bamboo vinegar and producing
furnace of bamboo charcoal

http://e-trade.ktc.ksrp.or.jp/en/seeds/kitakyu/e_104.html

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