[Digestion] In support of Biosystems

Björn Dahlroth bjorn.dahlroth at telia.com
Mon Nov 22 04:42:29 CST 2010


Hi everybody
This is a very important point of view. 

In farming and in small scale you have the resource - manure and various
organic residues available more or less on site, field for spreading
bio-fertiliser and compost will be close by, the electricity you buy from
the local utility might be expensive due to high low voltage distribution
cost and taxation or the fuel you use for cooking could be costly. On the
other hand you don't have the economy of scale. 

Now if you go to a large scale plant that is servicing a town or a city you
may have a more expensive resource as manure and agricultural residues are
further away and source separation and separate transport of food waste is
also expensive. The electricity produced is sold at a higher voltage and the
selling price you get is probably much lower than the local purchase price
that the farmer can use in his calculations.  Alternatively you can upgrade
the gas and use it for cars and buses but the upgrading is not cheap and
there will be gas losses. If you sell heat you may have to compete with
cheaper district heating. The field where you want to spread the
bio-fertiliser would be situated at quite some distance and tank car
transport is not cheap. Large scale spreading on fields might lead to great
nitrogen losses and soil compaction depending on how you do it and the price
of competing fertiliser could be low. In addition both the supply of
resources and the use of fertiliser and heating have in many the places such
strong and different patterns of seasonal variation that some kind of
storage might be required for both the resource and the products. Also
energy prices may have seasonal variation. In cooler places the digestion
plant might require heating depending on the process selected. All this is
negative for the economy. On the other hand you have the economy of scale in
investment and operation which is not unimportant and you have the fact that
waste -municipal, industrial or agricultural - is an eternal problem that
must be handled in some way or other. There are also always other
alternatives. 

Then political ideology comes in here and there. Many plants would not have
been built if it hadn't been for political ideology but politics is bit
unreliable if you look at it with a long term perspective. This accounts
also for environmental politics. Subsidies come and go, taxes go up at
different rates, laws and rules are changed now and then as various view
points are changed in popularity with changing opinions. 

In summary it is important to consider many circumstances if you work with
research in digestion, planning investment and supplying digestion plants. 
In spite of that it is probably possible to come to some conclusions about
where digesting in general seems to have its best niche (or niches)of future
application and where it is the obvious thing to do. It is a question that
deserves some discussion in a global network.

Regards 
Bjorn Dahlroth
Sweden




-----Ursprungligt meddelande-----
Från: digestion-bounces at lists.bioenergylists.org
[mailto:digestion-bounces at lists.bioenergylists.org] För Hoysall Chanakya
Skickat: den 22 november 2010 04:37
Till: paul.harris at adelaide.edu.au; For Discussion of Anaerobic Digestion
Ämne: [Digestion] In support of Biosystems

Ny last post titled perpetual motion machine was meant to be encouraging. 
I was trying to promote the central idea and not criticise it.  My
suggestion is that when agree to start a biosystem as outlined there we
need to plan the scale at which we need to operate.  For a biosystem, when
we begin to account for energy and material losses, we soon understand
that it becomes resource-wise sustainable only at a certain scale.  At
smaller scales it would not seem to be operational or sustainable.  Once
this size is established and found possible, the next step is to examine
its economic sustainability.  In order to make it cost-wise sustainable,
the scale of operation usually needs to be somewhat larger than the size 
found acceptable to meet the resource-sustainability criteria.  This is
because a certain level of profits needs to be built in - (taking from
Paul Harris's concept of leakage accounting)  We will need to see at what
size all these leakages (an inputs) become viable /sustainable etc.




> G'day All,
>
> We do get on to some interesting topics!
>
> Of course there are losses in the integrated biosystem that have to be
> made
> up by rainfall, sunshine and gas transfer, plus whatever nutrients are
> exported in produce will eventually have to be made up (no, I'm not trying
> to restart a previous thread - please!). It depends where you draw the
> boundary and how tight the boundary is. I once gave a paper about
> Integrated
> biosystems and pointed out that Adelaide (where the Conference was) was a
> "loose" integrated biosystem as lot's of products crossed the boundary but
> Planet Earth is a "tight" integrated biosystem as very little enters or
> leaves the biosphere. I can't find that paper just now, but here is an
> Integrated Biosystems one if you want some brief information <
> http://www.adelaide.edu.au/biogas/website/integratedbiosys.pdf or
> PowerPoint
> http://www.adelaide.edu.au/biogas/website/IntegratedBiosystems.pdf>.
>
> Happy digesting,
> HOOROO
>
> Mr. Paul Harris, Room S116b, Waite Main Building Faculty of Sciences, The 
> University of Adelaide, Waite Campus, PMB 1, Glen Osmond SA 5064 Ph    :
> +61
> 8 8303 7880      Fax   : +61 8 8303 4386
> mailto:paul.harris at adelaide.edu.au  
> http://www.adelaide.edu.au/directory/paul.harris
>
> CRICOS Provider Number 00123M
> This email message is intended only for the addressee(s) and contains
> information that may be confidential and/or copyright.  If you are not the
> intended recipient please notify the sender by reply email and immediately
> delete this email. Use, disclosure or reproduction of this email by anyone
> other than the intended recipient(s) is strictly prohibited. No
> representation is made that this email or any attachments are free of
> viruses. Virus scanning is recommended and is the responsibility of the
> recipient.
>
>
> -----Original Message-----
> From: digestion-bounces at lists.bioenergylists.org
> [mailto:digestion-bounces at lists.bioenergylists.org] On Behalf Of Hoysall
> Chanakya
> Sent: Sunday, 21 November 2010 10:04 PM
> To: For Discussion of Anaerobic Digestion
> Subject: [Digestion] the perpetual motion machine
>
> The grand perpetual motion machine symptoms,
> Not really - what you need to see is that there will be losses and
> leakages from this "grand system" and to keep it running you need to
> reduce your energy losses to minimum and have practically no N losses.  At
> some scale your dream will come true.  Then of course comes the cost -->
> where you need to decide if it is worth it afterall.
> best wishes
> chanakya
>
>
>
> _______________________________________________
> Digestion mailing list
>
> to Send a Message to the list, use the email address
> Digestion at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergyli
sts.org
>
> 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/
>
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
>
>


-- 
Dr. Hoysall Chanakya
Centre for Sustainable Technologies
(Assoc. Faculty at Centre for Infrastructure, Sustainable Transport and
Urban Planning (CiSTUP) and Centre for Contemporary Studies)
Indian Institute of Science, Bangalore 560 012
ph 91-80-2293 3046; fax-91 80 2360 0683


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.


_______________________________________________
Digestion mailing list

to Send a Message to the list, use the email address
Digestion at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergyli
sts.org

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/





More information about the Digestion mailing list