[Digestion] Attachment to previous Article - More scientific based research and questions

Murali Krishna bmkrishna6 at gmail.com
Tue Oct 26 21:48:15 PDT 2010


Dear Dr.Karve,

I had been to Wardah and  visited the said digester at CSV,  two years
back.  This digester was actually designed by Mr.Jianan Wang, a professor of
Physics from China.  This digester is known as Puxin Biogas model.  It works
on water Hydraulic Pressure. It is a mix of Deenabandu and Floating Drum.
The size and weight of iron drum is bigger and heavier in floating drum
model than Puxin digester.
It is usually fed once in six months.  The feeding rate is normal.  It does
not yield more gas than any other Indian digesters.  The digester's is
designed for 40/50 days HRT and is fed once in six months.  Farmers of China
fed this digester with waste grass clippings and dung/pig manure, etc.  They
are emptied once in six months and spread on their agricultural fields.
Since there are dry grass clippings and sufficient enough nitrogen  material
is available (C:N ratio is maintained) and the quantity of feed stock is
loaded for six months, the digester is giving 3 cubic meter gas every day
without further feed.

You w ere not properly appraised by the people at Wardah for they themselves
are not sure of the feed rate and no study is being conducted.  You must
have observed theat at CSV they have a canteen on the premises and everyday
kitchen waste is fed into the digester.  This they never  consider  nor
bring into  the notice  of anyoneav.  Similarly the same digesters which
they have built at the restidential colony is connected to night soil
regular feed source.
The digester is 10 cube meter and it is giving only 3 cube meter gas.  As
per the inventor in China's weather it will give 5 to 6 cube meter gas.  I
had been exchanging correspondence with Mr.Jianan for more than two months
during 2008-09 for designing 100 cube meter digester and go for 1 MW unit.
As the cost is quite exhorbitant  and my customers does not want this
model.  The advantage with this model is .....it is easy to empty and fill
the digester.   This  digester can be used for continuous feeding also.  I
have built this digester at Hyderabad and the mould was lent by CSV.

This is a patented model for water hydraulic pressure and unfortunately the
inventor's efforts are never acknowledged and many claim that it is their
own invention.

Regards,

Murali Krishna.


On Sun, Oct 24, 2010 at 12:13 AM, Anand Karve <adkarve at gmail.com> wrote:

> Dear Dr. Martin,
> I have just returned from a city called Wardha, where I attended a workshop
> arranged jointly by the Research Councils of UK and the Department of
> Science and Technology, Government of India. About 20 scientists each from
> UK and India were invited to this meeting.
> In the course of field visits organised during the workshop, Dr. Soham
> Pandya, The Director of Centre of Science for Villages, an NGO in Wardha,
> showed us an amazing biogas plant on his campus. This biogas plant accepts
> about 1000 kg cattle dung as a one-time load and produces daily about 3
> cubic meters of biogas, continuously over a period of about 180 days.  This
> is not the only biogas plant constructed by him. Using funds from the
> Department of Science and Technology, He has constructed a similar biogas
> plant in another place called Hingoli, where a one-time load  of 1000 kg
> dung yields biogas continuously for 6 months, to run an electricity
> generator for daily 3 to 4 hours, to provide electric lighting to all the
> houses in the village.  Officials of the Department of Science and
> Technology vouched for the veracity of these claims. According to text book
> knowledge, 1000 kg dung should have produced about 30,000 litres (or 30
> cubic meters) biogas. But this particular biogas plant produces 540 cubic
> meters of it.
> Neither Dr. Pandya nor any other scientist could give a
> scientific explanation to this phenomenally high yield of biogas. Dung of
> Indian cattle consists mainly of lignin (from the veins and midribs of the
> grass and leaves that they feed on) and micro-organisms. One has to assume
> in this case, that there are microbes in the dung that feed on the lignin
> and that the methanogens digested the lignin eating microbes.
> Yours
> A.D.Karve
>
> On Mon, Oct 18, 2010 at 3:53 PM, Duncan Martin <duncanjmartin at gmail.com>wrote:
>
>> Perhaps Dr Karve & I should agree to disagree?
>>
>> To argue that dung is not food for the methanogens because they need help
>> to digest it is really a semantic quibble. It misses the point I was
>> responding to - that the digestion process is not *completed *by the act
>> of defaecation, it is merely *terminated* for the owner of the gut in
>> question.
>>
>> I have never seen any serious literature suggesting that microbes are
>> altruistic. However, the principles of commensalism are well established and
>> I see no basis for dismissing them. Moreover, the complex web of metabolic
>> interactions in AD has been extensively researched and is pretty well
>> understood - though I am sure there is more to discover.
>>
>> Nor have I seen any literature whatsoever suggesting that the methanogens
>> consume other microorganisms. I would be intrigued to see a proposed
>> mechanism.
>>
>> To dismiss all the textbooks as wrong (see previous postings) is
>> unhelpful, at best. Who could only say that unless he had read every one of
>> them? Of course, there are mistakes - even in the best books - if only
>> because science moves on, so any book becomes outdated. And there are indeed
>> some layman's guides to AD that include some odd ideas - but who would take
>> them as serious guides to the science?
>>
>> When we find such errors, let us use this forum to report them - giving
>> exact references. But lets not confuse newcomers to the field by dismissing
>> every other source of information as rubbish.
>>
>> Finally, let us accept that each of us is entitled to his opinion - but
>> lets reserve this forum for the fruits of practical experience and
>> evidence-based information.
>>
>> I suggest we draw a line under the present debate.
>>
>> Duncan Martin, PhD, MCIWM, MIChemE, MIEI
>> Cloughjordan Ecovillage
>> Ireland
>>
>> On 17 October 2010 16:39, Anand Karve <adkarve at gmail.com> wrote:
>>
>>> Dear Duncan,
>>> I dont believe in the theory of a chain of micro-organisms, with one
>>> species converting the cellulose into glucose, another converting the
>>> glucose into an organic acid (e.g. citric acid), still another converting
>>> the organic acid into acetic acid and ultimately the acetic acid being
>>> converted by the methanogenic organisms into carbon dioxide and methane. If
>>> this were true, one would have by now isolated the organism that converted
>>> cellulose into glucose and used the glucose to produce alcohol. Cellulose is
>>> the most ubiquitously found organic compount in the world and with this
>>> simple process, one would have produced unlimited quantity of liquid fuel.
>>> But even today, the conversion of cellulose into glucose is achieved in any
>>> industrial process by using a cellulolytic enzyme extracted from a
>>> cellulolytic organism. The reason for this is, that the glucose converted by
>>> the organism from cellulose is consumed by the same organism. And once it is
>>> consumed by an organism, it is converted into its cell all the way down to
>>> carbon dioxide. The micro-organisms in the gut of an animal cannot be
>>> expected to be so altruistic as to predigest the food and suply it to the
>>> methanogens. I feel that the methanogenic organisms consume the fellow
>>> micro-organisms in the gut of animals and digest them to produce methane and
>>> carbon dioxide. Such dog-eat-dog reactions occur also in the soil supplied
>>> with organic matter.
>>>         In any case, once it is accepted that the methanogenic organisms
>>> do not digest the dung directly and that they need the help of other
>>> organisms to digest it, one cannot accept that dung is the food of the
>>> methanogens. It is like saying that manure applied to a field is human food,
>>> because through a number of biological processes it ultimately ends up into
>>> products, which the humans eat.
>>> Yours
>>> A.D.Karve
>>>  On Fri, Oct 15, 2010 at 4:27 PM, Duncan Martin <duncanjmartin at gmail.com
>>> > wrote:
>>>
>>>>
>>>> Yes, the gut methanogens do, in a sense, eat what the animal eats.
>>>> However, it would be more accurate to say that their diet is derived from
>>>> what the animal eats. The methanogens in the gut of a cow are surrounded by
>>>> celluose and other biopolymers but they cannot digest them. They live on the
>>>> waste products of other microbial processes. The web of metabolic
>>>> interactions is well known.
>>>>
>>>> Where I would "hoot out" Dr Karve is his belief that dung cannot serve
>>>> as food for the methanogens because they are "thrown out" of the body along
>>>> with the dung. I don't understand the logic here.
>>>>
>>>>
>>>>
>>> _______________________________________________
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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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>>
>> 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/
>>
>>
>>
>
>
> --
> ***
> Dr. A.D. Karve
> President, Appropriate Rural Technology Institute (ARTI)
>
> *Please change my email address in your records to: adkarve at gmail.com *
>
>
>
>
> _______________________________________________
> Digestion mailing list
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> to Send a Message to the list, use the email address
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> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.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/
>
>
>
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