[Digestion] Digestion Digest, Vol 14, Issue 7

Mon Aug 13 06:55:45 EDT 2007

I could not recognise your name from the message I received, but thank's for 
your comments and help.
I am interested to learn from your drawings, once they can show that 
although this digesters can be very simple the costs can be quite different 
if we introduce some design features.

Best wishes,

Luís Ferreira
----- Original Message ----- 
From: <g_vishwas at vsnl.com>
To: <digestion at listserv.repp.org>
Sent: Sunday, August 12, 2007 4:23 AM
Subject: Re: [Digestion] Digestion Digest, Vol 14, Issue 7

> If you operating plug flow digester it is the simplest and most reliable 
> digester . This is precisely why it has survived for such a long time.  If 
> you have substrates which degrade fast or contain some inhibitory 
> compounds then careful monitoring is required. You can size the digester 
> to 40 to 60 days retention time based on your
> local temperature conditions. If you provide a bafle system it may 
> increase the efficiency. It also helps if you make compartments which are 
> individualy covered . Maintainance without shutting off the digester 
> system is also possible. If you have a proper slurry preparation system 
> using mechanical device or compressed air mixing it will give you still 
> better performance. If interested I can give you drawings from which you 
> can construct the digester yourself.
>
>
> ----- Original Message -----
> From: digestion-request at listserv.repp.org
> Date: Sunday, August 12, 2007 12:01 am
> Subject: Digestion Digest, Vol 14, Issue 7
> To: digestion at listserv.repp.org are operating
>
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>> Today's Topics:
>>
>>   1. Re: Your help to up-date costs of farm scale AD plants (Len
>> Walde)
>>
>> -------------------------------------------------------------------
>> ---
>>
>> Message: 1
>> Date: Fri, 10 Aug 2007 17:36:47 -0700
>> From: "Len Walde" <sigma at ix.netcom.com>
>> Subject: Re: [Digestion] Your help to up-date costs of farm scale AD
>> plants
>> To: Lu?s Ferreira <lferreira at isa.utl.pt>,
>> <bioenergy at listserv.repp.org>, <digestion at listserv.repp.org>
>> Message-ID: <13d301c7dbaf$b8bc33d0$0a0110ac at Len>
>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>> reply-type=original
>>
>> Luis:
>>
>> I my opinion, the plug flow technology has not changed to any
>> great extent
>> over the years so do not be concerned.  The reason it has survived
>> is its
>> simplicity --- plug flow!  You can dress it up with recorders,
>> gauges, and
>> data collectors of all types but it is still the same simple
>> system, that
>> requires a "Hands-on" approach to operate.
>>
>> I suggest you search the AG STAR files for Leo Langerwerth ( Check
>> Spelling )  as he has continually operated his system since the
>> 1980's,
>> except to clean it out of sand,  about ten years ago. ( +/- ) .
>> Much has
>> been written about Leo's dairy and system, read all you can about
>> and you
>> will get an education in the technology. I doubt Leo will respond
>> to
>> requests for information,  as I  bet he is tired of answering the
>> same
>> questions over and over again!  I know I would if I were in his
>> place --- as
>> I said it is all in the articles.  I think it might be worth your
>> time to
>> visit Durham CA  to see his system first hand -- That I think that
>> Leo will
>> welcome you if asked nicely.  He is a great guy!
>>
>> As for the financial end of the business, you will have to
>> "crunch" your own
>> numbers, beginning with your business plan built on local costs
>> and economic
>> conditions.  If you need help with this I suggest  you contact a
>> local
>> University with a Business School, and ask for pro bono help or
>> hire a
>> consultant --  ( might be expensive ). If you do your own Business
>> Plan you
>> will get an education worth the effort.  I would!  Search the web
>> for
>> "Business Plan" and you will see what that effort involves.
>>
>> The above is shared " for what it is worth".  Good luck
>>
>> Len Walde, P.E.
>>
>>
>> ----- Original Message ----- 
>> From: "Lu?s Ferreira" <lferreira at isa.utl.pt>
>> To: <bioenergy at listserv.repp.org>; <digestion at listserv.repp.org>
>> Sent: Friday, August 10, 2007 6:39 AM
>> Subject: [Digestion] Your help to up-date costs of farm scale AD
>> plants
>>
>> Dear List,
>>
>> Has some of you probably have already noticed from the last couple
>> of days,
>> I'm trying to learn more about the economics of Farm scale AD
>> Plants based
>> on Plug-flow digesters.
>>
>> Some of the information available from the AgSTAR program case
>> studies has
>> almost 10 years. Therefore I feel the need to find the present
>> values of
>> these costs to 2007!
>>
>> I would be very thankfull if I could get your advice (specially
>> comming from
>> those who are working in this matters) about what should be the
>> recommendale
>> interest rate to be used in this up-date of costs, for U.S reality.
>>
>> Thank you in advance for your help.
>>
>> Best wishes,
>>
>> Lu?s Ferreira
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>>
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>> End of Digestion Digest, Vol 14, Issue 7
>> ****************************************
>>
>
> Vishwas Gokhale
> http//www.gitassociates.com
>
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> 