[Stoves] material processing for briquettes few tips ontechnique

[Kevin]

Dear Andrew

Very interesting possible explanation for why "spent agricultural lime" 
helps with the anaerobic retting process!

While Ca(OH)2, or "Hydrated lime" can have a pH as high as  about 12.5, and 
is indeed very caustic, CaCO3 or "Limestone", "agriculture lime, "land 
lime", has a pH in the range of about 8, which is not very caustic at all

Is there perhaps another possibility, that being that a marginal change in 
alkalinity favours growth of different bacteria?

More specifically, is it perhaps the minor change in pH is "shifting the bug 
balance", rather than making local chemistry harsher? In other words, are 
the "retting fungus forms" more favoured with slightly higher pH, while the 
fungus forms that consume cellulose are repressed?

Best wishes,

Kevin



----- Original Message ----- 
From: <ajheggie at gmail.com>
To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org>
Sent: Saturday, August 04, 2012 2:04 PM
Subject: Re: [Stoves] material processing for briquettes few tips 
ontechnique


> On Fri, 3 Aug 2012 10:32:14 -0700, Richard Stanley wrote:
>
>>If processed correctly,  natural fibers will flex and then tend to 
>>interlock once blended with other materials in a water slurry.
>>One does not  achieve this by simple chopping or even direct use of the 
>>fiber without some form of softening (thru partial decompsition, in a hot 
>>humid anerobic environment,  (under such as a black plastic bag), or as we 
>>are learning from our Mayan colleagues in Guatemala,  use of agricultural 
>>lime (which is traditionally discarded after its use in hot water to 
>>soften and de-shell their corn kernals).
>
> As always I find your posts on briquetting educational.
>
> Alkalis, lime being calcium hydroxide, dissolve lignin and I expect
> this is what the bugs do in retting fibres out of the stem
> (simplistically wood rotting fungi can be classified into brown, white
> and soft rots, the white rots attack lignin and leave the cellulose,
> brown eat the cellulose and soft rots invade all the cells), it's
> lignin that hold all the stringy fibres together. So I can see how
> lime would separate out the fibres.
>
> Your observation that the bugs work better in anaerobic conditions
> may be that this is what favours a white rot. Flax sheaves where laid
> in a water filled ditch to ret.
>
> I may have missed something in Rok's post: Rok mentions 16cms diameter
> briquettes with a 5 cms hole, I take it it is the length he is varying
> between 3-12 cms and favouring a length of between 5 and 7cms?
>
> AJH
>
>
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