[Digestion] Digestion Digest, Vol 5, Issue 2., large Scale Digester for Municipal Waste (Bernd Haase)

Sat Nov 4 04:40:04 CST 2006

Thank you for that background Ramanujam

However, I think it is important to note that dry digestion can be 
mesophilic - or even psychrophilic. How else do landfills yield biogas, even 
in cold climates? Large ones do warm up - but often fail to reach 
thermophilic temps.

It would be more correct to say (and this may be what you meant) that 
working in the thermophilic regime gives the advantage of a faster process. 
This increases the throughput in a costly plant, so the economics are 
better.

However, it might be more accurate to say that this is true for the CURRENT 
forms of the process, which favour large plants of quite high technical 
complexity. It might not be so for a low-tech plant.

My own researches suggest it is worth investigating much simpler process 
variants, in which low rates are offset by simpler, cheaper, more reliable 
equipment. I've posted a list of some published papers (over 20 in all) here 
before but I can send a copy to anyone interested.

Best regards

Duncan J Martin

Chair
Republic of Ireland Centre
Chartered Institution of Wastes Management,

================================
CONTACT DETAILS
Duncan J Martin, PhD, CEng, CSci, MIEI, MCIWM, MIChemE
24 Townsfield, Cloughjordan, N Tipperary, Ireland
Mobile: +353 86 8377 906
Email: duncanjmartin at eircom.net
================================

----- Original Message ----- 
From: "R.A. Ramanujam" <rar_envtech at yahoo.com>
To: <digestion at listserv.repp.org>
Sent: Saturday, November 04, 2006 4:51 AM
Subject: Re: [Digestion] Digestion Digest, Vol 5, Issue 2.,large Scale 
Digester for Municipal Waste (Bernd Haase)

> Dear Bernd
>
>  There is no low tech large scale digester operational in India for 
> municipal solid waste.  There is a plant operating in Chennai city of 
> Tamil Nadu India exclusively for Vegetable market waste. Its capacity is 
> 30 tpd. It is low soilds concentration digester. The maximum gas 
> generation achieved was 1700 cum/d.  It is only a demo plant.  Therefore 
> we are working on the system to increse the solids concentration to 
> increase the gas production to 2000 - 2300 cum/d. Dry fermentation 
> processes have not been  implemented in India till now in large scale as 
> that kind proceeses have to be operated only in thermophilic condition. 
> The biogas generated have to be utilised partly for heating the digester 
> contents. The available gas for energy generation will get reduced.  The 
> economic viability of the project is not of acceptable level.
>
>  regards
>  Ramanujam
>  Assistant Director, Dept of Environmental Technology
>  Central Leather Research Institute
>  Adyar, Chennai 600 020
>  Telefax: +91-44-24450234
>  email: rar_envtech at yahoo.com
>
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> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 3 Nov 2006 07:34:34 +0100 (CET)
> From: "Bernd Haase"
> Subject: [Digestion] large Scale Digester for Municipal Waste
> To: digestion at listserv.repp.org
> Message-ID:
> <1864.203.189.135.187.1162535674.squirrel at webmail.hs-bremen.de>
> Content-Type: text/plain;charset=iso-8859-1
>
> Hey colleagues,
>
> I'm working on a feasibility study in phnom penh for the anaerobic
> treatment of municipal waste. I'm wondering if some of you have heared
> about a low-tech large scale plant that works successfully. I heard rumors
> that india has plants running, but couldn't find anything in the web.
> Please let me now about dry fermentation plants that use household or
> marktet waste as substrat.
>
> thanx bernd
>
>
>
>
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