Re: DIG-L: Anaerobic digestion

[Simm <simm@mozcom.com>]

Dear Lisa,

thermophilic digesters require a pretty advanced heat management setup.
Convective losses are higher, but preheating the fresh material, or meeting
heat demands after feeding "cold" material is a lot trickier. You might
need external heat. And the thermophilic process is not as stable as the
mesophilic one. Unless you really need to drastically reduce pathogenes I
do not see a clear advantage to elevate the temperature. 

Good luck,

Anthony Simm


At 11:51 AM 02/12/2000 +0000, you wrote:
>Dear all,
>
>My name is Lisa Pritchard and I currently work for a company called
>GreenfinchLtd based in Shropshire, UK.  Our demonstration plant is a 20m3
>anaerobic digester which treats  5-7 tonnes of source-separated household
>kitchen waste (biowaste) each week  from approximately 1500 households.  
>
>One of our objectives is to recycle and reuse of by-products of the AD
>process.  This does not include agricultural land application.  As you
>know regulations are getting tighter so we do not want to rely on land
>application to reuse the nutrients effectively.  Hence we are reusing our
>by-products through various processes including aquaculture and
>vermiculture.
>
>Our digester is mesophilc. Do you see any clear advantages for running our
>digester at thermophilic temperatures, bearing in mind our climate and
>need to reuse all by-products?
>
>Thankyou and look forward to any replies,
>
>Lisa Pritchard
>
>
>   
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