[Stoves] Meat grinder fuels for TLUDs was Re: wheat husk pellets

[Paul Olivier]

See comments below.


On Thu, Jun 13, 2013 at 3:05 PM, <ajheggie at gmail.com> wrote:

> [Default] On Wed, 12 Jun 2013 15:41:13 +0700,Paul Olivier
> <paul.olivier at esrla.com> wrote:
>
> >How durable is a pellet made from boiled starch or clay?
>
> Fairly durable, just look at the charcoal briquettes that are sold,
> they seem to hold their form as they burn, mostly these are made with
> an opposed roller to form them.
>

I am not interested in briquettes but pellets.

>
> >What is the percentage of starch or clay added?
> >What is the cost of these additives?
>
> Elsen Karlstad did a lot of work on charcoal fines and clay, in
> essence the raw material was fee, do a search on the archive for
> chardust.
>

Chardust does not the same elasticity as rice hulls and many other forms of
biomass.


>
> >How do these additives affect the moisture content and other properties of
> >the pellets?
>
> I don't know but once dry it should make no difference.
>

Yes, moisture content makes a big difference.


>
> >But is this extra cost not worth it in terms of a higher efficiency in its
> >final use?
>
> Tom has posted a comprehensive explanation of the bonding, the
> advantages of a dry, dense pellet with low ash content are to do with
> transport costs and better combustion, less ash to fuse or interfere
> with combustion. You can cram more fuel into a tighter space for
> controlled combustion.
>

I do not fully understand what you are saying here.
With the conventional pellet, do we not have all of the same advantages.


>
>
> >If not, then why do companies often make pellets without the use of
> starch,
> >clay or other additives?
>
> Because it's a purer product and cheaper ingredients at the cost of
> much higher capital cost equipment and power.
>

Of course a purer product using cheaper ingredients has advantages.
But what is the difference in capital cost and power?
Right now in Vietnam I can buy a tone of rice hull pellets for $76 US
dollars.
This, of course, is using conventional pellet equipment.
How much cheaper would things be if one were to use a meat grinder and
additives?



> >If ligin plasticizes, does this not make the pellet more hydrophobic?
>
> In theory yes but all these  processes are a black art, it simply
> doens't pay to put any more work into the pellet than necessary to
> hold it together for the purpose for which it is made.


If the pellet ends up with the same MC and BTU, and if it does break up in
handling, then what you say makes sense.
I really want to explore this option.


> So I suspect
> only the outside skin deforms as described, the inner particles as
> simply crushed togetehr to eliminate cell and interstital spaces and
> then they presumably are close enough to have the hydrogen bonding Tom
> describes.
>
> If you don't need to transport the fuel far the costs of running a
> pellet mill (high capital investment, relatively high power
> consumption, high wear costs) don't stack up compared with the Legacy
> type medium density briquette which burns well, has low investment,
> uses cheap or waste agricultural residues although it has a high
> labour content and needs drying before use.
>

Yes, but you say briquette here.
In a TLUD a pellet is ideal.


>
> >How does one get a uniform flow of air in a TLUD using hexagonal logs?
> >How does one avoid CO2 formation using hexagonal logs?
>
> I've never tried one TLUD.
>

I am afraid that logs in a TLUD will produce a lot of CO2 as a result of
too much combustion far below the pot.

Thanks.
Paul

>
> AJH
>
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-- 
Paul A. Olivier PhD
26/5 Phu Dong Thien Vuong
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/
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