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paper clay now: kiln gasses

updated sun 31 mar 96


Karl David Knudson on sun 31 mar 96

On Fri, 29 Mar 1996, Louis Howard Katz wrote:
> ----------------------------Original message----------------------------
> Since the initial combustion takes place at a low temperture I would
> assume that much of the paper is not completely combusted. The assumption
> that because kilns get as hot as 2350 degrees that all fuel is completely
> combusted and that only water and CO2 are produced is faulty. Kilns are
> not always above 700 degrees or 1000 or 1200, all sorts of things must
> sneak out of organic material put in kilns. Vent it.

Has anyone has actually measured kiln exhaust and compiled percentages of
what by-products were produced? Electric, gas. wood, or salt would all
be interesting to know. I did some digging at the Science Library a
while back and only found combustion experiments done in China on
wood burning at various temperatures in a vacuum (ie no O2 present).
Suprisingly, if I remember correctly, the majority of the gasses given
off were CO, CO2, H2O, H2 and C2H2, with their relative percentages
changing as temperature increased.