[Bioconversion] Grass Pellets

[AJH]

On Mon, 6 Feb 2006 23:14:19 -0500, William Carr wrote:

>I was told Kaolin Clay powder would help and I'm testing it now.   It  
>does help prevent slag from adhering to the steel stirring rod in my  
>corn stove.

I'll be pleased to hear the results, I thought kaolin was decayed
granite, china clay, is this not an aluminium compound?

I was not aware corn burning stoves had these stirring rods. I burn
wheat and barley in my pellet stove but have returned to burning them
in 50:50 proportions with wood pellets. One of the drawbacks is that
the fused ash is aerated and thus occupies more space, this means the
burn pot needs 6 hourly cleaning out rather than daily. I imagine a
steel stirrer would reduce this lightly fused ash.

I wonder if the kaolin dilutes the potassium compounds such that they
cannot fuse, or perhaps there is something there that combines with
the potassium and prevents it volatising.

Tom Miles has previously indicated that potassium compounds are
volatilised at very low temperatures. So if the burn pot temperature
can be kept low can we retain more potassium in the ash?

A feature of the pellet stoves I see is that the secondary flame is
almost all diffused, i.e. almost no premixing. Tom Reed in a posting
to [stoves] has complained that some biomass feed stocks do not burn
well. I wonder if this is related to the problems of flame length in a
diffuse flame, like a candle as you increase the wick length you get
to the stage when the flame becomes sooty because the interface with
the surrounding air cannot supply enough oxygen before the reaction
cools.

AJH