[Digestion] Meso and Thermophilic Operating Temperature

davidf@kingdombio.co.uk Fulford davidf at kingdombio.co.uk
Sun Jun 8 21:52:45 CDT 2014


Bram and listers, Hello,
In my book, "Running a biogas programme" (1988) Practical Action, I present 
a simple First Order Rate model, developed at Cornell University. The 
theory separates the concepts of total yield of biogas and the rate of 
generation. Increasing temperature does not increase total yield, but it 
does increase the rate of generation (how quickly you can achieve that 
total yield). The variation of rate with temperature can be modeled with 
the Arrhenius equation, In my book, I present some results that were done 
by a student of mine, which show how the theory works in practice.
Best wishes,Dr David Fulford
Kingdom Bioenergy Ltd

----------------------------------------
From: "Heegde BA ter, Bram" <b.a.ter.heegde at st.hanze.nl>
Sent: Friday, June 06, 2014 11:28 AM
To: "digestion at lists.bioenergylists.org" 
<digestion at lists.bioenergylists.org>
Subject: Re: [Digestion] Meso and Thermophilic Operating Temperature 

Thank you for that HOOROO, a very valuble resource, the S curve is indeed a 
very good fit. 

However, it still leaves me with a question, or more of an area that isn't 
quite clear yet. You speak of rate, I assume you mean conversion rate. I've 
always believed and understood that conversion rate and yield are two sides 
of the same coin. If temperature increases the conversion rate, which is 
what the XL model does shows, doesn't it also mean that you are able to 
retrieve more biogas per kg of digestate. Which in my mind is an increase 
in yield. I am aware that at a given temperature the only way to increase 
yield is with loading rate and retention time. 

I am however looking at the difference between the gas yield at ambient 
operating temperatures (ca. 20 degrees) and at the mesophilic range. What 
I've understood form quite a few research papers is that the yield and 
coversion rate wil increase. 

I think that possibly my understanding in the difference of Yield and 
conversion rate my not be completly correct. 

Regards. 

Bram ter Heegde
NAW: 258757
Mob. Tel: 0653134337

________________________________________
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[digestion-request at lists.bioenergylists.org]
Sent: 05 June 2014 20:00
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Subject: Digestion Digest, Vol 45, Issue 2

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Today's Topics:

   1. Re: Meso and Thermophilic Operating Temperature
      (Heegde BA ter, Bram)
   2. Re: Meso and Thermophilic Operating Temperature
      (harrisfm at aapt.net.au)

----------------------------------------------------------------------

Message: 1
Date: Thu, 5 Jun 2014 08:32:31 +0000
From: "Heegde BA ter, Bram" 
To: "digestion at lists.bioenergylists.org"

Subject: Re: [Digestion] Meso and Thermophilic Operating Temperature
Message-ID:
        <00C145A1644CD9468CEDDB6B9991F25F11E8C3BF at HPEMB08W28.hanze.nl>
Content-Type: text/plain; charset="us-ascii"

Thank you for the paper, it is indeed an interesting graph, however not 
quite the one I was looking for.

Maybe I should be a little clearer as to what I am trying to 
achieve/inverstigate.

Two things that I would like to find out are, firstly, what is the effect 
of increasing digester temperature on gas Yield. With this I mean not only 
the absolute amount of gas produced but also the effect that temperature 
has on reaction time of the digester. I would also be interested in if the 
yield increases in an linear pattern in relation to the temperature, or if 
it is exponential/non-linear/etc, This is why I was looking for the graph 
of temp vs. biogas yield. I seem to remember that it wasn't a linear 
relationship. However, form experiments it does look like a linear 
relationship.

That is the main issue Im trying to solve at the moment.

Secondly I'm interested in the effect of ammonia loading at increased 
digester temperatures.

Met vriendelijke groet;

Bram ter Heegde
NAW: 258757
Mob. Tel: 0653134337

________________________________________
From: Digestion [digestion-bounces at lists.bioenergylists.org] on behalf of 
digestion-request at lists.bioenergylists.org 
[digestion-request at lists.bioenergylists.org]
Sent: 04 June 2014 20:00
To: digestion at lists.bioenergylists.org
Subject: Digestion Digest, Vol 45, Issue 1

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Today's Topics:

   1. Meso and Thermophilic Operating Temperature (Heegde BA ter, Bram)
   2. Re: Meso and Thermophilic Operating Temperature (Les Gornall)

----------------------------------------------------------------------

Message: 1
Date: Wed, 4 Jun 2014 15:18:59 +0000
From: "Heegde BA ter, Bram" 
To: "digestion at lists.bioenergylists.org"

Subject: [Digestion] Meso and Thermophilic Operating Temperature
Message-ID:
        <00C145A1644CD9468CEDDB6B9991F25F11E8C356 at HPEMB08W28.hanze.nl>
Content-Type: text/plain; charset="iso-8859-1"

Dear all,

I am a student at the Hanze Universtity of Applied Sciences and am 
currently investigating the possibilty of using waste heat to heat a biogas 
digester.

However, somewhere in my research I came accross a graph depicting the gas 
yield from cow dung in a biogas digester at the meso and at the 
thermophilic range.

It would be very handy to have that graph, and it's source, however I have 
spent the last two days looking for it and can't seem to find it.

Hope someone can point me in the right direction.

Kind regards/Met vriendelijke groet;

Bram ter Heegde
NAW: 258757
Mob. Tel: 0653134337

------------------------------

Message: 2
Date: Wed, 4 Jun 2014 16:04:57 +0000
From: Les Gornall 
To: For Discussion of Anaerobic Digestion

Subject: Re: [Digestion] Meso and Thermophilic Operating Temperature
Message-ID:
        <4E83BE1704C70148BF9A0FC1ED1B54132DA72501 at EX01.projen.co.uk>
Content-Type: text/plain; charset="iso-8859-1"

http://www.pelagiaresearchlibrary.com/advances-in-applied-science/vol3-iss3/
AASR-2012-3-3-1864-1869.pdf

This paper has a nice graph

Best Regards

Les Gornall
Process Consultant

PROjEN PLC
Process Consultant
DD:         01928 752 568
Email:    les.gornall at projen.co.uk

PROjEN HOUSE
Wellfield
Preston Brook
Runcorn
WA7 3AZ

Reception: +44 (0) 1928 752 500
www.projenbioenergy.co.uk

-----Original Message-----
From: Digestion [mailto:digestion-bounces at lists.bioenergylists.org] On 
Behalf Of Heegde BA ter, Bram
Sent: 04 June 2014 16:19
To: digestion at lists.bioenergylists.org
Subject: [Digestion] Meso and Thermophilic Operating Temperature

Dear all,

I am a student at the Hanze Universtity of Applied Sciences and am 
currently investigating the possibilty of using waste heat to heat a biogas 
digester.

However, somewhere in my research I came accross a graph depicting the gas 
yield from cow dung in a biogas digester at the meso and at the 
thermophilic range.

It would be very handy to have that graph, and it's source, however I have 
spent the last two days looking for it and can't seem to find it.

Hope someone can point me in the right direction.

Kind regards/Met vriendelijke groet;

Bram ter Heegde
NAW: 258757
Mob. Tel: 0653134337

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End of Digestion Digest, Vol 45, Issue 1
****************************************

------------------------------

Message: 2
Date: Thu, 05 Jun 2014 18:44:04 +0800
From: harrisfm at aapt.net.au
To: "For Discussion of Anaerobic Digestion"

Subject: Re: [Digestion] Meso and Thermophilic Operating Temperature
Message-ID:
        <052f8c830ce521a35f080bd5003f58000922ea2e at webmail.iinet.net.au>
Content-Type: text/plain; charset="utf-8"

?G'day Bram,
Chen's Model (available in XL as digcalc.zip at
biogas.wikispaces.com/Online+Course) shows that it is just the RATE
that changes with temperature, the YIELD only changes with loading
rate/retention time. If you treat a given volume of effluent for
longer Retention Times at lower temperatures you will get the same
volume of biogas. In the "normal" mesophilic range a linear
relationship of rate to temperature is a good fit, but I found the
best fit for 10C to 50C(?) is an S curve. I don't have access to XL or
my files on this computer so can't give more assistance at the moment.
I have not followed ammonia loading.
Good luck,HOOROO

----- Original Message -----
From: "For Discussion of Anaerobic Digestion"
To:"digestion at lists.bioenergylists.org"
Cc:
Sent:Thu, 5 Jun 2014 08:32:31 +0000
Subject:Re: [Digestion] Meso and Thermophilic Operating Temperature

 Thank you for the paper, it is indeed an interesting graph, however
not quite the one I was looking for.

 Maybe I should be a little clearer as to what I am trying to
achieve/inverstigate.

 Two things that I would like to find out are, firstly, what is the
effect of increasing digester temperature on gas Yield. With this I
mean not only the absolute amount of gas produced but also the effect
that temperature has on reaction time of the digester. I would also be
interested in if the yield increases in an linear pattern in relation
to the temperature, or if it is exponential/non-linear/etc, This is
why I was looking for the graph of temp vs. biogas yield. I seem to
remember that it wasn't a linear relationship. However, form
experiments it does look like a linear relationship.

 That is the main issue Im trying to solve at the moment.

 Secondly I'm interested in the effect of ammonia loading at increased
digester temperatures.

 Met vriendelijke groet;

 Bram ter Heegde
 NAW: 258757
 Mob. Tel: 0653134337

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for more information about digestion, see
Beginner's Guide to Biogas
http://www.adelaide.edu.au/biogas/
and the Biogas Wiki http://biogas.wikispaces.com/

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and the Biogas Wiki http://biogas.wikispaces.com/

  
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