[Terrapreta] heat energy: stoves vs. thermo biopiles

[mmbtupr at aol.com]

from   Lewis L Smith

 From experience, I am familiar with the concepts of high and low 
heating values, and vaguely recall hearing Dominicans, Hawaiians and/or 
Puerto Ricans argue about which one is "best".

However, there is a formula called "Hessey's formula" which was once 
widely used in the Hawaiian sugar industry for calculating the heating 
value of cane bagasse. So it provided me with a rough-and-ready, 
professionally acceptable means of calculating the heating value of any 
tropical grass, in doing the economics of the project evaluations which 
we performed during the years 1970-90, especially when I was working 
with Hawaiians.

Now it just so happens that the Formula is expressed in terms of HHV, 
so it is convenient when one is dealing with different drying options 
for "energy grass".

In any case, I never got a complaint. Moreover, as I recall from a 
Hawaiian report, there are five ways in which energy is wasted in a 
biomass boiler, so I did never figure out why we should give special 
treatment to H2O !  But then, I am not an engineer !

Cordially. ###





-----Original Message-----
From: Jeff Davis <jeff0124 at velocity.net>
To: terrapreta <terrapreta at bioenergylists.org>
Sent: Fri, Nov 23  9:15 PM
Subject: Re: [Terrapreta] heat energy: stoves vs. thermo biopiles

Dear All,

When one burns fuel, for the most part, you use the lower heating value 
of the
fuel.


Jeff



On Friday 23 November 2007 3:06 pm, Sean K. Barry wrote:
> Hi Gerrit,
>
> I suspect its 80% of the released heat, not 80% of the combustible 
energy
> in the biomass feed.  Capturing 80% of the combustible energy is 
about as
> good as any complete combustion (burning) process could ever do.  That
> would leave just ash.  It even 25 or 30% of the original carbon is 
left in
> the biomass, then this constitutes at least 60% of the energy content 
of
> the feed also.  I'm sure the total energy harvest efficiency from 
making
> compost is much much lower than 80%.
>
> Compost does make better fertilizer, to be sure, than charcoal does, 
even
> low temperature charcoal.  It has been suggested more than once on 
this
> site that charcoal could be combined with compost to make a soil 
amendment
> which is initially more fertile than fresh charcoal.
>
> Regards,
>
> SKB
>   ----- Original Message -----
>   From: Gerald Van Koeverden<mailto:vnkvrdn at yahoo.ca>
>   To: jeff0124 at velocity.net<mailto:jeff0124 at velocity.net>
>   Cc: terrapreta<mailto:terrapreta at bioenergylists.org>
>   Sent: Friday, November 23, 2007 12:19 PM
>   Subject: [Terrapreta] heat energy: stoves vs. thermo biopiles
>
>
>   Jeff,
>
>   I like the idea of hyour thermo biopile.
>
>   Composting to produce energy definitely has the advantage of
>   producing a much better fertilizer- the compost - than ash from
>   burning.  But it seems that less total energy is available by
>   composting, though if the biomass had to be dried before burning, 
the
>   resultant net energies might be conquerable?
>
>   A company in Canada (Global earth Services/Products) sells a 
compost-
>   maker with a built-in heat exchanger.  They claim to capture 80% of
>   the energy.  I interpret this "80%" to be 80% of what would be the
>   combustible energy.
>
>
> 
http://www.globalearthproducts.com/heat_extraction.htm<http://www.globalear
>thproducts.com/heat_extraction.htm>
>
>   Gerrit
>
>   On 23-Nov-07, at 12:34 AM, Jeff Davis wrote:
>   > Dear All,
>   >
>   > Right now all my time is going into the Thermo Biopile:
>   > 
http://www.puffergas.com/pile/pile.html<http://www.puffergas.com/pile/p
>   >ile.html>

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