[Stoves] Stoves Digest, Vol 11, Issue 29

Wed May 9 00:54:05 CDT 2007

Dear Karve,

"We just put a weight on the gas holder" is work. That's the source of the
"missing" energy.

Peter Coughlin

On 5/9/07, stoves-request at listserv.repp.org <
stoves-request at listserv.repp.org> wrote:
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> Today's Topics:
>
>   1. Re: Compact biogas plant (David G. LeVine)
>   2. Re: Compact biogas plant (David G. LeVine)
>   3. Re: Compact biogas plant (acparker at xmission.com)
>   4. Re: Compact biogas plant (David G. LeVine)
>   5. Re: Compact biogas plant (steve)
>   6. Re: Compact biogas plant (Robert Taylor)
>   7. Re: Compact biogas plant (Robert Taylor)
>   8. Re: Compact biogas plant (David G. LeVine)
>   9. Re: Compact biogas plant Pressure (Simon and Zoe)
> 10.  Roadside biodiesel (acparker at xmission.com)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 08 May 2007 13:13:39 -0400
> From: "David G. LeVine" <dlevine at speakeasy.net>
> Subject: Re: [Stoves] Compact biogas plant
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID:
>        <
> mailman.2841.1178680489.3071.stoves_listserv.repp.org at listserv.repp.org>
>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> Okay, so how does the weight get on the holder?
>
> Work is weight through an energy difference (on earth, usually a
> distance under gravity.)  It requires energy to do that work.
>
> Just because YOU don't supply the energy doesn't mean that energy is
> not supplied.  When you burn wood, you supply no energy, but the sun
> supplied the energy content of the wood.  When the gas is compressed
> the energy to do so comes from somewhere.  You may not supply it, the
> gas producing organisms do.
>
> That is the real issue that politicians have, they will give you free
> money than raise taxes to cover the cost of government.  That money
> is part of the "cost of government."
>
> The compressed gas is "free", but something pays the "tax", in this
> case the digester pays the tax and reduces the output, much like any
> political organism.  Raise the "tax" high enough, and the whole thing
> collapses.  That is pretty simple.
>
> At 03:09 AM 5/8/2007, you wrote:
> >No energy is used to compress the gas. We just put a weight on the gas
> >holder so that the weight presses on the gas in the gas holder. It is the
> >gravity of earth that is working for us.
> >Yours
> >  A.D.Karve
> >
> >----- Original Message -----
> >From: David G. LeVine <dlevine at speakeasy.net>
> >To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> >Sent: Monday, May 07, 2007 7:43 AM
> >Subject: Re: [Stoves] Compact biogas plant
> >
> >
> > > At 12:26 PM 5/6/2007, you wrote:
> > > >In all such cases, we found that the amount of biogas produced under
> > > >pressure was less than the amount produced without the weight.
> > >
> > > Question:  If energy is used to pressurize gas, where does it come
> from?
> > >
> > > Question:  If the energy used to compress the gas is not needed,
> > > where does it go?
> > >
> > > I believe (and I can be wrong) that the amount of gas is related to
> > > the energy used for other processes.  If I use 1 MJ to compress the
> > > gas, that 1 MJ comes from somewhere, and is no longer available for
> > > gas production.
> > >
> > >
> > > David G. LeVine
> > > Nashua, NH  03060
> > >
> > >
> > > _______________________________________________
> > > Stoves mailing list
> > > Stoves at listserv.repp.org
> > > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> > > http://www.bioenergylists.org
> >
> >
> >_______________________________________________
> >Stoves mailing list
> >Stoves at listserv.repp.org
> >http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> >http://www.bioenergylists.org
> >
> >
> >
> >--
> >No virus found in this incoming message.
> >Checked by AVG Free Edition.
> >Version: 7.5.467 / Virus Database: 269.6.5/793 - Release Date:
> >5/7/2007 2:55 PM
>
> David G. LeVine
> Nashua, NH  03060
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 08 May 2007 13:18:07 -0400
> From: "David G. LeVine" <dlevine at speakeasy.net>
> Subject: Re: [Stoves] Compact biogas plant
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID:
>        <
> mailman.2842.1178680489.3071.stoves_listserv.repp.org at listserv.repp.org>
>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
>
> >"Common Sense" would suggest that they make less gas when working
> >under pressure.
>
> Exactly my point.
>
>
> David G. LeVine
> Nashua, NH  03060
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 08 May 2007 12:36:22 -0600
> From: acparker at xmission.com
> Subject: Re: [Stoves] Compact biogas plant
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID: <4640C326.B09E8D2 at xmission.com>
> Content-Type: text/plain; charset=us-ascii
>
> Could a separate holding tank be utilized that could be pressurized when
> needed, therefore not effecting the output of the bacteria?
>
>
> Andrew Parker
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 08 May 2007 15:43:23 -0400
> From: "David G. LeVine" <dlevine at speakeasy.net>
> Subject: Re: [Stoves] Compact biogas plant
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID:
>        <
> mailman.2843.1178680489.3071.stoves_listserv.repp.org at listserv.repp.org>
>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> At 02:36 PM 5/8/2007, you wrote:
> >Could a separate holding tank be utilized that could be pressurized
> >when needed, therefore not effecting the output of the bacteria?
>
> Yes, but the energy to compress the gas comes from somewhere.
>
>
> David G. LeVine
> Nashua, NH  03060
>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 08 May 2007 19:53:53 GMT
> From: "steve" <steve at thetaylorfamily.org.uk>
> Subject: Re: [Stoves] Compact biogas plant
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID: <4640d551.3d.494c.1581253735 at thetaylorfamily.org.uk>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> > Yes, but the energy to compress the gas comes from
> > somewhere.
>
> That SAID, the amount of energy might be fairly minimal - if
> the flames are around 500 W, you could raise 1 tonne 3
> metres in a minute.
>
> Steve
>
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 9 May 2007 04:09:01 +0800
> From: "Robert Taylor" <rt at ms1.hinet.net>
> Subject: Re: [Stoves] Compact biogas plant
> To: "Discussion of biomass cooking stoves" <stoves at listserv.repp.org>
> Message-ID: <04f201c791ac$ed364df0$c700a8c0 at s200rt>
> Content-Type: text/plain; format=flowed; charset="ISO-8859-1";
>        reply-type=original
>
> >>Could a separate holding tank be utilized that could be pressurized
> >>when needed, therefore not effecting the output of the bacteria?
> >
> > Yes, but the energy to compress the gas comes from somewhere.
>
> That could be supplied by somebody lifting a stone onto the holding tank,
> with a non-return valve between the digester and the holding tank. They
> would have to remember to take it off again after cooking was finished, to
> avoid raising the pressure in the digester.
>
> Robert Taylor
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Wed, 9 May 2007 05:20:01 +0800
> From: "Robert Taylor" <rt at ms1.hinet.net>
> Subject: Re: [Stoves] Compact biogas plant
> To: "Discussion of biomass cooking stoves" <stoves at listserv.repp.org>
> Message-ID: <04f901c791b6$aefa67b0$c700a8c0 at s200rt>
> Content-Type: text/plain; format=flowed; charset="ISO-8859-1";
>        reply-type=original
>
> >> Yes, but the energy to compress the gas comes from somewhere.
> >
> > That could be supplied by somebody lifting a stone onto the holding
> tank,
> > with a non-return valve between the digester and the holding tank. They
> > would have to remember to take it off again after cooking was finished,
> to
> > avoid raising the pressure in the digester.
>
> Duh... of course, that could just as well be done by lifting the stone
> onto
> and off the digester itself, thus preserving the compactness and
> simplicity
> of the original system. And a non-return valve would also raise the
> pressure
> in the digester, though not necessarily by very much.
>
> Robert Taylor
>
>
>
>
> ------------------------------
>
> Message: 8
> Date: Tue, 08 May 2007 21:07:05 -0400
> From: "David G. LeVine" <dlevine at speakeasy.net>
> Subject: Re: [Stoves] Compact biogas plant
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID:
>        <
> mailman.2844.1178680489.3071.stoves_listserv.repp.org at listserv.repp.org>
>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> At 03:53 PM 5/8/2007, you wrote:
>
> > > Yes, but the energy to compress the gas comes from
> > > somewhere.
> >
> >That SAID, the amount of energy might be fairly minimal - if
> >the flames are around 500 W, you could raise 1 tonne 3
> >metres in a minute.
>
> I won't disagree.  I only point out that a bigger tube may be less
> costly than the compressing system, whatever it is.
>
>
> David G. LeVine
> Nashua, NH  03060
>
>
>
>
> ------------------------------
>
> Message: 9
> Date: Wed, 9 May 2007 08:53:34 +0545
> From: "Simon and Zoe" <simonandzoe at yakpost.net>
> Subject: Re: [Stoves] Compact biogas plant Pressure
> To: "Discussion of biomass cooking stoves" <stoves at listserv.repp.org>
> Message-ID: <001901c791e7$c85e13b0$b92c4fca at user1sksov2b5j>
> Content-Type: text/plain;       charset="iso-8859-1"
>
> Let's put some numbers into this discussion to see just how insignificant
> the energy is:
>
> - Assuming a compact plant with a floating tank 1 square metre in area.
>
> - In order to supply 10mBar of pressure this needs to be weighted to 100
> Kg
>
> - If it fills with 1 cubic metre of gas it lifts 1m, total energy required
> for lift is 1000 Joules.
>
> Assuming calorific value of 24 MJ/cubic metre for the stored gas, the
> energy
> used to lift the holding tank represents less than 0.005% of the stored
> energy.
>
> Incidentally research here in Nepal (back in the 70s & 80s) was unable to
> detect a perceptible difference in gas production with changing pressure.
>
>
>
> ----- Original Message -----
> From: "Robert Taylor" <rt at ms1.hinet.net>
> To: "Discussion of biomass cooking stoves" <stoves at listserv.repp.org>
> Sent: Wednesday, May 09, 2007 3:05 AM
> Subject: Re: [Stoves] Compact biogas plant
>
>
> > >> Yes, but the energy to compress the gas comes from somewhere.
> > >
> > > That could be supplied by somebody lifting a stone onto the holding
> tank,
> > > with a non-return valve between the digester and the holding tank.
> They
> > > would have to remember to take it off again after cooking was
> finished,
> to
> > > avoid raising the pressure in the digester.
> >
> > Duh... of course, that could just as well be done by lifting the stone
> onto
> > and off the digester itself, thus preserving the compactness and
> simplicity
> > of the original system. And a non-return valve would also raise the
> pressure
> > in the digester, though not necessarily by very much.
> >
> > Robert Taylor
> >
> >
> > _______________________________________________
> > Stoves mailing list
> > Stoves at listserv.repp.org
> > http://listserv.repp.org/mailman/listinfo/stoves_listserv.repp.org
> > http://www.bioenergylists.org
> >
>
>
>
>
> ------------------------------
>
> Message: 10
> Date: Tue, 08 May 2007 21:14:45 -0600
> From: acparker at xmission.com
> Subject: [Stoves]  Roadside biodiesel
> To: Discussion of biomass cooking stoves <stoves at listserv.repp.org>
> Message-ID: <46413CA5.C3629B7A at xmission.com>
> Content-Type: text/plain; charset=us-ascii
>
> What a coincidence.  We discuss the merits of raising Jatropha along the
> rail beds of India and today the State of Utah announces that they are
> funding a five year experiment to determine if it is economically
> feasible to supply the biodiesel needs of the Utah Department of
> Transportation's (UDOT) biodiesel needs by planting oil seed plants on
> the State's right-of-way's.  The expectation is that they could produce
> an average of 200 gallons of B100 biodiesel for every mile of
> right-of-way planted in safflower, camelina, canola and perennial flax.
> They also expect to save about $1.6 million annually in mowing costs.
> <http://origin.sltrib.com/ci_5846719>
>
> I anticipate two possible problems: high salinity from winter road
> salting, and grazing in rural areas (The grass along the highways is
> very good. It makes use of a kind of runoff agriculture from the
> pavement, and many ranchers make use of it.  There is nothing quite so
> invigorating as noticing in your peripheral vision the nose of a 600
> pound Black Angus flash by six inches from your side mirror at 60 miles
> an hour on a dark night.)  Otherwise, a great idea, if it works.
>
>
> Andrew Parker
>
>
>
> ------------------------------
>
> _______________________________________________
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>
> End of Stoves Digest, Vol 11, Issue 29
> **************************************
>

-- 
Dr. Peter Coughlin
Partner
EconPolicy Research Group, Lda.
Av. Paulo Samuel Kankhomba, 1381, r/c
Maputo, Mozambique
Telefax.: (258) 21-305131
Cell: (258) 84- 317-1080
admin at econpolicy.org
coughlinpeter at gmail.com