[Digestion] Digestion Digest, Vol 4, Issue 7

[stan simon]

The amount of heat required is calculated by the sum of the heat lost from 
the surface of the digester and the amount of heat required to warm the 
incoming effluent.  To put it in mathematical terms,

q= UA(Tdigester-Toutside ambient) + MC(Tdigester- Tincoming)

where q is heat required
U is the u value of the digester enclosure ( reciprocal of sum of 'R' 
values)
A is the surface area of the digester
M is the mass flow rate into the digester
C is the specific heat of the effluent ( since it is mostly water you could 
figure 1 btu per pound per deg F)  That will get you in the ball park.

----- Original Message ----- 
From: <digestion-request at listserv.repp.org>
To: <digestion at listserv.repp.org>
Sent: Friday, October 27, 2006 12:00 PM
Subject: Digestion Digest, Vol 4, Issue 7


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> Today's Topics:
>
>   1. Heat input required to maintain optimum digester temp
>      (Jason Perry)
>   2. about carbon credits (Shrinivas Kasulla)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 27 Oct 2006 15:58:12 +0100
> From: Jason Perry <perry.jason at gmail.com>
> Subject: [Digestion] Heat input required to maintain optimum digester
> temp
> To: digestion at listserv.repp.org
> Message-ID: <45421E84.6040605 at gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Greetings all,
>
> I am new to this list and fairly new to biodigesters. I am living in
> Scotland but am originally from northeastern New York. I am working on a
> master's thesis for an MSc program run by the Centre for Alternative
> Technology (CAT) in Wales. The object of my thesis is to determine how
> much of my hometown's energy demand could be met by diverting existing
> biomass waste flows into use as bioenergy feedstocks. This includes
> dairy manure, corn stover, apple orchard prunings, apple waste, etc.
>
> My question for today is this:
> How might I estimate the amount of heat input required to maintain the
> optimum temperature in a plug-flow dairy manure digester throughout the
> year in the given climate? I have been playing around with Farmware but
> it is clear that it is only a superficial tool. I realize that this
> figure is going to depend on a huge number of factors, but it would be
> good even if I could establish a range. Perhaps this could be expressed
> as a fraction of the heat value of the theoretical amount of gas produced.
>
> Thanks for any ideas about where I might start.
>
> Jason
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 27 Oct 2006 08:49:52 -0700 (PDT)
> From: Shrinivas Kasulla <na_sh81 at yahoo.co.in>
> Subject: [Digestion] about carbon credits
> To: digestion at listserv.repp.org
> Message-ID: <20061027154952.57567.qmail at web53906.mail.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> Dear Respected PANEL,
> am working on a project of waste management can any
> one plz help me about carbon credits plz i mean my
> input material would be wet biodegradable solid waste
> so how much quantity of methane would be there in one
> tone of waste and how much would be carbon dioxide as
> far as methane percentage is concern it would be
> around 75-80% and carbon dioxide would be rest 20-25%
> without any traces of H2S and lil bit of moisture
> contents.
> all the help would be appreciated and would be an
> added advantage to my knowledge.
>
> thanking you
> srinivas kasulla
>
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> End of Digestion Digest, Vol 4, Issue 7
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