[CZARCAR (OP)]

http://www.smartburn.com.au/wood-fire-smoke/How+it+Works    whats the ingredients?

[CliffordK]

"Natural" is somewhat of a catch-all.
Coal and Petroleum, for example are "natural".
As are rocks, and many other things that you wouldn't choose to eat.

Unfortunately I'm striking out on finding the ingredients.  The information says that it was patented, maybe in 2003 in Australia, so perhaps that should lead a search. 

Or, of course, one could buy one, cut it open, and see what is actually inside.

It indicates that it melts in the indirect heat of a fire...  so a few hundred degrees tops.

I'm thinking of an organic salt, although many organic salts will create odd flame colors.  There is a discussion of the acidity of the creosote.  So...  I might try a strong organic base, for example sodium ethoxide, but that would tend to have a bit high of a melting point.   

Maybe I'm thinking of it wrong.  Ash is basic (NaOH/KOH), so perhaps the problem isn't a lack of Sodium/Potassium, but too much of it.  It could be balanced with halocarbons, but those could be bad for the environment.

Keep in mind that all that is "natural" doesn't mean it is safe.  Sodium Cyanide is relatively natural, relatively heat stable, and quite toxic.  Glycerin is natural and non toxic, but breaks down to Acrolein which is toxic.

Metals and metal ions are also good for catalysts.  So, perhaps a metal salt?  I presume it would be heat stable, and last a long time.  Years ago, we had a container of "fire sprinkles" that gave flashes of odd colors.  I'm trying to remember if there was supposed to be any benefit from them, or if it was just to make colorful flames.  This discusses salts and colored flames, but no discussion about the overall effect on the smoke.

[CZARCAR (OP)]

thanx

[damocles]

The combustion of any carbon/hydrogen/oxygen based material is a very complicated process involving free radical mechanisms and chain reactions.

If a material can be added at the level of a few gram to make a hotter fire, it would need to be providing either a radical source or a radical trap, and inserting its own chain carrier into the system (or increasing the concentration of a chain carrier that is already present). that is the only way that a small amount of additive could work for a large amount of fire.

It might also help if the material contained an efficient dessiccant (removed the water produced in the reaction), but with the scale of fuel:additive it is difficult to see how that could have much effect. It would be most efficient if the material acted as a catalyst (i.e. were regenerated rather than consumed in the overall combustion).

Of the many materials that might work, most are either very toxic, or explosive, or both. But it is possible that something very simple -- a salt like magnesium nitrate or an easily decomposed organic like paraformaldehyde -- has been found that will do the job.