Thanks All for the background documents. These are extremely useful. <br><br>Best,<br><br>A<br><br><div class="gmail_quote">On Thu, Oct 7, 2010 at 7:56 AM, David Fulford <span dir="ltr"><<a href="mailto:davidf@kingdombio.com">davidf@kingdombio.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000">
Hello Alex and Listers,<br>
<br>
The best independent papers on the ARTI system are by EAWAG (<a href="http://www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_swm/index_EN#owm" target="_blank">www.eawag.ch/organisation/abteilungen/sandec/publikationen/publications_swm/</a>)
who have also looked at the digestion of food residues from markets
in Kerala, South India. While food residues have an average TS of
50% or less, Dr Karve bases his results on starch residues (e.g.
flour dropped on the floor from milling). Suich residues have a TS
of almost 100%. This means that we need to consider his gas
production results as per kg total solids, rather than per kg of wet
material.<br>
<br>
As the assessor from Ashden Awards who visited ARTI in 2006 (see <a href="http://www.ashdenawards.org/winners/arti06" target="_blank">www.ashdenawards.org/winners/arti06</a>),
I had to evaluate Dr Karve's statements.and his technology. The
biogas plant uses simple cylindrical drums, so there is nothing
special about the design. The major difference is the use of food
residues rather than dung as the feed material. Since an animal has
used as much of the input energy in the food as it can before it
evacuates the rest, the gas production from undigested food is
likely to be much higher than that from dung. Processed food (flour,
sugar and cooked food) is likely to have a higher gas output than
raw food, as much more of the material is accessible to the
microbes. There are several other biogas projects in India using
food residues as feed material, that started at about the same time
as the ARTI one. I have visited the first Biotech Ltd project in
Kerala (<a href="http://www.ashdenawards.org/winners/biotech" target="_blank">www.ashdenawards.org/winners/biotech</a>)
about which the EAWAG report was written and another in Mumbai
called the Nisargruna system developed by BARC (see <a href="http://www.green-ensys.org/site/Biogas_Plant.html" target="_blank">www.green-ensys.org/site/Biogas_Plant.html</a>),
which uses a two-stage digestor design.<br>
<br>
Looking at the basic thermodynamics of the process, it seems quite
feasible to generate 1 kWh of electrical energy from 1 kg of starch,
as Dr Karve suggests, although it does suggest a very high
efficiency for the conversion of starch to biogas. However, in
practice, a 1 cu.m ARTI biogas plant is too small to run an ic
engine, as small ic engines are not very efficient.<br>
<br>
Regards,<br>
<br>
David Fulford<div class="im"><br>
<br>
On 07/10/2010 01:39, Alexander Eaton wrote:
<blockquote type="cite">Dr Karve, <br>
<br>
Your innovation and work in the field is quite appreciated, and
your system really opens doors for us who are also not technically
focused in the biology of biogas, but rather its application to
families and communities. That is why it seems your use of food
waste and loading rates based on gas production for a family
really widens the populations we may be able to work with
globally. Do you have a paper or document that has this data and
other user data available? <br>
<br>
Best,<br>
<br>
Alex<br>
<br>
<div class="gmail_quote">On Wed, Oct 6, 2010 at 5:40 PM, Anand
Karve <span dir="ltr"><<a href="mailto:adkarve@gmail.com" target="_blank">adkarve@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div>Dear Alexnder,</div>
<div>to be quite frank, I do not call myself an expert in
biogas technology. I developed my system as a layman. Being
a biologist, I argued that since all industrial fermentation
systems used sugar, why not try it in a biogas plant.
Because sugar was costly, I used only 1 kg sugar in a biogas
plant that consumed daily 40 kg cattle dung. To my surprise
I found that I got about 700 to 800 litres of biogas, just
24 hours later. Since sugar was costly, I shifted to using
flour of cereal grains, which also gave similar results.
Then we tested spoilt milk, oilcakes of various edible and
non-edible oilseeds and peels of fruits like banana, mango
and papaya, and got similar results. We then constructed
biogas plants geared to using food waste as feedstock. It
was by trial and error, that we arrived at our present
configuration which is just a conventional moving dome
biogas plant. The rule of thumb is to use 1 g (dry weight)
of food waste per litre of digester capacity. When I
started talking about our system in conferences on biogas, I
used to be hooted out by the experts. Once they found out
that I had no theoretical knowledge of the biogas
plants, they would embarass me by asking questions like C:N
ratio, volatile solids % etc. It was only after our system
received the Ashden Award in London (2006), that the world
started believing in me. <br>
Yours</div>
<div>A.D.Karve<br>
</div>
<div>
<div>
<div class="gmail_quote">On Thu, Oct 7, 2010 at 7:00 AM,
Alexander Eaton <span dir="ltr"><<a href="mailto:alex@sistemabiobolsa.com" target="_blank">alex@sistemabiobolsa.com</a>></span>
wrote:<br>
<blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0px 0px 0px 0.8ex; padding-left: 1ex;" class="gmail_quote">Hi Dr. Karve, <br>
<br>
I recently had the pleasure of meeting your associate
and representative for Tanzania at a conference in
Sweden. He explained much of the same thing about the
ARTI system. When you describe your system as
primarily a biogas generation system (as opposed to
waste treatment), do you mean that you optimize HRT
and loading rates for biogas production, rather than
balancing biogas production with the reduction of
organic load (TOC or COD?). Reviewing the plans of
your systems, it does not seem as though the vessel
itself holds massive differences with any other AD
reactor, so can we assume that this is a management
practice, versus technology comparison? <br>
<br>
Best,<br>
<br>
Alex <br>
<div>
<div><br>
<div class="gmail_quote">On Wed, Oct 6, 2010 at
4:45 PM, Anand Karve <span dir="ltr"><<a href="mailto:adkarve@gmail.com" target="_blank">adkarve@gmail.com</a>></span>
wrote:<br>
<blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;" class="gmail_quote">
<div>Dear Alexander,</div>
<div>thanks for the correction. In our system,
1 kg (dry) food waste provides 1 kW
electricity for 1 hour. I am absolutely sure
of these figures, because we are daily
generating electricity on our own campus by
using food waste from our own hostel. If
your calculations show our system to be 3
times as efficient as the one reported in
the article, then it must be so. All I can
claim is that our biogas production system
is currently the cheapest and the most
efficient biogas system in the world.
Scientists of a prestigeous Institute of the
Government of India had come to us to have a
look at our biogas system, because using the
same amount of waste, our system produced 10
times as much biogas as the two phase
system developed by them. The
report submitted by them to their bosses
explained the difference in the performance
of the two systems being due to the fact
that their system was primarily a waste
disposal system, whereas ours was primarily
a biogas generating system. So far, we have
installed about 5000 such biogas plants all
over India and also about 50 on the African
continent. </div>
<div>Yours</div>
<div>A.D.Karve <br>
<br>
</div>
</blockquote>
</div>
</div>
</div>
</blockquote>
</div>
</div>
</div>
</blockquote>
</div>
</blockquote>
</div><font color="#888888"><div>-- <br>
<p align="center">********************************************************************<br>
Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5
4PU <br>
<a href="mailto:d.j.fulford@btinternet.com" target="_blank">d.j.fulford@btinternet.com</a>,
Tel: +44(0)118 326 9779 Mob: +44(0)7746 806401 <br>
Kingdom Bioenergy Ltd, <a href="http://www.kingdombio.com" target="_blank">www.kingdombio.com</a>,
<a href="mailto:davidf@kindombio.com" target="_blank">davidf@kindombio.com</a> </p>
</div>
</font></div>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Alexander Eaton<br>Sistema Biobolsa<br>IRRI-Mexico<br><br>Mex cel: (55) 11522786<br>US cel: 970 275 4505<br><br><a href="mailto:alex@sistemabiobolsa.com" target="_blank">alex@sistemabiobolsa.com</a><br>
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