[Gasification] combustion of tarry producer gas
Gero Eckermann
info at carboconsult.com
Mon Oct 29 07:54:31 EDT 2007
Dear Jim, Mark and all,
I have yet to see a gasifier which (as Jim hopes and says) "should be able
to deal with: mixed construction waste with nails, plastic cups, newspaper,
cardboard boxes, dimensioned lumber, coffee, brush
clippings, tires, water bottles, etc etc etc".
We have been producing tar free gas in our "single zone" commercial down
draft gasifiers since 1984, when our mentor and partner Gustaf Johansson
made the breakthrough to crack tar in the reaction zone at +/- 1500degC.
In my humble opinion, any biomass contamination with metal, rubber and / or
plastics can only lead to disaster, anything else mentioned but then in
briquetted form at the required size and less than 20% humidity will
probably work, as long as it contains lignin (or any other starchy biomass
compound).
Why bother "pulling the zones apart", re-experimenting with updraft and
wasting a lot of time and money, when others have already gone that way and
failed?
Anyway, perhaps I am a bit too harsh with the enthusiastic experimenters,
but I still believe you chaps should go the old and trusted Imbert way and
get the reaction zone temperature up from about 800 to 1500 degC.
With tar free gas regards,
Gero Eckermann
www.carboconsult.com
-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of
gasification-request at listserv.repp.org
Sent: 29 October 2007 10:39 AM
To: gasification at listserv.repp.org
Subject: Gasification Digest, Vol 16, Issue 28
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Today's Topics:
1. Re: combustion of tarry producer gas (jim mason)
2. Re: combustion of tarry producer gas (jim mason)
3. Two stage gasification (Art Krenzel)
4. Re: Two stage gasification (Tom Miles)
5. Re: combustion of tarry producer gas (Bob Stuart)
6. Cigarette gasifiers and CO (Thomas Reed)
7. Re: Cigarette gasifiers and CO (jim mason)
8. FW: Gasification Digest, Vol 16, Issue 27 (Malcolm Lefcort)
9. Re: FW: Gasification Digest, Vol 16, Issue 27 (Mark Ludlow)
10. Re: Two stage gasification (Mark Ludlow)
11. Wood Cubes from Saw Dust (Pasidu Pallawela)
12. Re: Two stage gasification (jim mason)
----------------------------------------------------------------------
Message: 1
Date: Sun, 28 Oct 2007 12:31:15 -0700
From: "jim mason" <jimmason at whatiamupto.com>
Subject: Re: [Gasification] combustion of tarry producer gas
To: "Mark Ludlow" <mark at ludlow.com>
Cc: gasification at listserv.repp.org
Message-ID:
<31a4f6f00710281231i5b68df75u8c425e5818e04e2b at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
On 10/27/07, Mark Ludlow <mark at ludlow.com> wrote:
>
> I agree, in priciple. But the challenge for widespread application of
> gasification demands that small-unit applications not be fuel sensitive.
> (Who wouldn't love to have almond shells to run?) Face it: an updraft
> gasifier where fuel can be dumped on a reactive bed is the simplest
> scenario. Sure, it takes no advantage of passing the pyrolyzed gas through
a
> cracking zone. But I have a sneaking suspicion that combining all
> requirements of tar-free gasification in a single device may not be the
most
> practical solution in all instances (my apologies to Doug Williams). It's
> certainly more elegant to have a single chamber doing gasification and
> cracking but who would refuse access to a fuel source composed of only
> charcoal even if, lb-for-lb, its HHV was less than properly-sized dry
> biomass? Everyone would rather avoid tar from the outset by having pure C
as
> a fuel (in an ideal world). But is it possible to "close-couple"
> gasification and tar cracking without making them integral to a single
> process?
>
i apologize if i created the impression that i think updrafts are off the
table. of course there are many applications and subprocess needs where an
updraft is well suited. the requirements for dealing with the output gas
can be complicated if more than an immediate close coupled burn, without
passing through a fan.
mark is correct that a great attraction of an updraft is its fuel
flexibility. as the air/gasflow is going in the opposite direction of
gravity, they are much less likely to cake up. higher moistures will only
degrade the energy in the product gas, but not stop the gasifier from
working, like in a downdraft.
at this point i don't find any single vessel solution to be able to
adequately process fuels with the needed flexibility for tolerable real
operation, and produce a consistent tar free gas. the self regulating
simplicity of combustion against reduction, with radiated/conection heat
running pyrolysis, in a single vessel is elegant in its minimalism, but it
is famoustly difficult to control. the self-regulating character of these
single vessel solutions only work within a very narrow band of fuel and air
humidity conditions. i find the world to not easily provide these
conditions. thus most gasification efforts become fuel standardization
efforts. and very few survive this transformation.
most all my work towards fuel agnostic, tar free gasifiers, is moving
towards pulling each of the zones apart and contending with them separately,
either in dedicated and well separated spaces in a "single vessel", or a
fully separate dedicated vessel. the processes can then be recombined and
controlled actively with microprocessors so that the great variation in
performance as fuel changes, can be compensated for in real time. i don't
have a finished system yet, but i'm going as fast as i can.
such gasifiers cannot be built from junk quite so easily, but they also hold
the potential to actually work in real world conditions.
for inspiration, i keep a large dumpster bin of real world organic matter
outside my shop. it has the waste of the world in it that i think a
gasifier should be able to deal with: mixed construction waste with nails,
plastic cups, newspaper, cardboard boxes, dimensioned lumber, coffee, brush
clippings, tires, water bottles, etc etc etc. i stare at this pile daily to
remind myself of the range of what a gasifier needs to be able to intake to
actually fulfill its promise of "energy from any waste biomass"
right now we are mostly at "energy from very carefully preprocessed forms of
organic waste, handled with such care and knowledge, that they are really a
high grade fuel again before they go in the gasifier". and thus is why so
few current small scale gasfiier installations ever work in the end. the
limitations of fuel type and condition, as well as expertise required to
maintain these conditions, is not reasonable for typical users.
we are not going to solve this problem with any minor tweak to an imbert
type. but i think we can solve it by the thoughtful separation and control
of the subprocesses, with active embedded control for recombining the parts
and flows between them. this will result in hybrid systems that have
combinations of various "traditional" types into a single system. and yes,
updrafts might be quite important as subprocesses in such a system.
j
Rex Z. has expressed a vision of a dual-zone reactor. Few experimenters or
> small-scale devotees are likely to attempt the fluid bed model that he
> describes, but a critical notion is the physical division of gasification
> and 'refinement' within a continuous flow stream. In its simplest
> expression, optimizing a primary generator to become an efficient
converter
> of solid feed substrate to gas is one task; and providing the environment
to
> reduce this gas to short-chain combustible components becomes the second
> task.
>
>
>
> Gasification, in its present popular incarnation, assumes that cracking of
> tarry gas requires a parasitic process deriving energy from the primary
> reaction zone. This is very elegant, in theory, but is dependent on a
number
> of mechanical parameters such as fuel condition and form factor. I ask:
> cannot the tars from a simple updraft gasifier be considered a fuel source
> unto themselves? Between their gaseous state and their troublesome
> crystallized state there must be a liquid state that would facilitate
their
> transport back into either the primary gasification/reduction zone or a
> secondary oxidation zone, providing energy for the primary gasification
> transformation.
>
>
>
> Am I dreaming?
>
>
>
> Mark
>
>
>
> *From:* jimmmason at gmail.com [mailto:jimmmason at gmail.com] *On Behalf Of
*jim
> mason
> *Sent:* Saturday, October 27, 2007 12:27 AM
> *To:* mark at ludlow.com; Discussion of biomass pyrolysis and gasification
> *Subject:* Re: [Gasification] combustion of tarry producer gas
>
>
>
>
>
> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:Tom,
> What do you estimate that the temperature of condensation of typical
> woodgas
> tar is?
> Mark
> --------------------------
>
> this is commonly desciribed as above 350degC
>
> but really, there is a tremendous variation between primary, secondary and
> tertiary tars. or light and heavy. depending how terms are defined.
>
> leland has much more experience in long running installation than i and
> many others here. my knowledge is only from running prototype rigs to
> date. so in general, i defer to leland and other like experienced elders
in
> this endeavor.
>
> so yes, avoid updraft gasifiers with biomass at nearly all costs. make
> clean gas from the begininng. innumerable problems will be less onerous
> downstream if you do so.
>
> jim
>
>
> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:
>
> Tom,
> What do you estimate that the temperature of condensation of typical
> woodgas
> tar is?
> Mark
>
> -----Original Message-----
> From: gasification-bounces at listserv.repp.org
> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of
> LINVENT at aol.com
> Sent: Friday, October 26, 2007 10:35 PM
> To: jimmason at whatiamupto.com; gasification at listserv.repp.org
> Subject: Re: [Gasification] combustion of tarry producer gas
>
> Burning tarry producer gas may appear to be an easy job, but after a while
> there are problems with it. One is that the tars may crack around the hot
> combustion areas and carbon up the pipes, ports apertures or other parts
> exposed to
> the direct or indirect heat from the combustion of the gas. Tars will
> condense
> anywhere in the transport pipes. Once condensed, they will solidify over
> time
> and block the pipes. They also drip off the end of the combustion pipe
> into
> the combustion chamber and pile up or burn within the chamber. If any long
> term
> usage of them is expected without significant pipe cleaning downtime, the
> gas
> needs to be clean.
>
>
>
> Sincerely,
> Leland T. Taylor
> Leland T."Tom" Taylor
> President
> Thermogenics Inc.
> 7100-F 2nd St. NW Albuquerque, NM 87107
> Phone:505-463-8422 Fax:505-268-9206 (call first)
> Web: thermogenics.com
>
>
>
> **************************************
> See what's new at http://www.aol.com
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
>
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
>
>
>
> --
>
>
----------------------------------------------------------------------------
----
> jim mason
> website: www.whatiamupto.com
> current project: mechabolic ( http://www.mechabolic.org)
> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
>
--
----------------------------------------------------------------------------
----
jim mason
website: www.whatiamupto.com
current project: mechabolic (http://www.mechabolic.org)
announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
------------------------------
Message: 2
Date: Sun, 28 Oct 2007 12:34:46 -0700
From: "jim mason" <jimmason at whatiamupto.com>
Subject: Re: [Gasification] combustion of tarry producer gas
To: "Mark Ludlow" <mark at ludlow.com>
Cc: gasification at listserv.repp.org
Message-ID:
<31a4f6f00710281234x47117c28oce85ca967550c789 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
On 10/27/07, Mark Ludlow <mark at ludlow.com> wrote:
>
>
>
> Rex Z. has expressed a vision of a dual-zone reactor. Few experimenters or
> small-scale devotees are likely to attempt the fluid bed model that he
> describes, but a critical notion is the physical division of gasification
> and 'refinement' within a continuous flow stream. In its simplest
> expression, optimizing a primary generator to become an efficient
converter
> of solid feed substrate to gas is one task; and providing the environment
to
> reduce this gas to short-chain combustible components becomes the second
> task.
>
mark, i missed this thread. this sounds interesting. where did rex
describe this?
j
Am I dreaming?
>
Mark
>
>
>
> *From:* jimmmason at gmail.com [mailto:jimmmason at gmail.com] *On Behalf Of
*jim
> mason
> *Sent:* Saturday, October 27, 2007 12:27 AM
> *To:* mark at ludlow.com; Discussion of biomass pyrolysis and gasification
> *Subject:* Re: [Gasification] combustion of tarry producer gas
>
>
>
>
>
> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:Tom,
> What do you estimate that the temperature of condensation of typical
> woodgas
> tar is?
> Mark
> --------------------------
>
> this is commonly desciribed as above 350degC
>
> but really, there is a tremendous variation between primary, secondary and
> tertiary tars. or light and heavy. depending how terms are defined.
>
> leland has much more experience in long running installation than i and
> many others here. my knowledge is only from running prototype rigs to
> date. so in general, i defer to leland and other like experienced elders
in
> this endeavor.
>
> so yes, avoid updraft gasifiers with biomass at nearly all costs. make
> clean gas from the begininng. innumerable problems will be less onerous
> downstream if you do so.
>
> jim
>
>
> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:
>
> Tom,
> What do you estimate that the temperature of condensation of typical
> woodgas
> tar is?
> Mark
>
> -----Original Message-----
> From: gasification-bounces at listserv.repp.org
> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of
> LINVENT at aol.com
> Sent: Friday, October 26, 2007 10:35 PM
> To: jimmason at whatiamupto.com; gasification at listserv.repp.org
> Subject: Re: [Gasification] combustion of tarry producer gas
>
> Burning tarry producer gas may appear to be an easy job, but after a while
> there are problems with it. One is that the tars may crack around the hot
> combustion areas and carbon up the pipes, ports apertures or other parts
> exposed to
> the direct or indirect heat from the combustion of the gas. Tars will
> condense
> anywhere in the transport pipes. Once condensed, they will solidify over
> time
> and block the pipes. They also drip off the end of the combustion pipe
> into
> the combustion chamber and pile up or burn within the chamber. If any long
> term
> usage of them is expected without significant pipe cleaning downtime, the
> gas
> needs to be clean.
>
>
>
> Sincerely,
> Leland T. Taylor
> Leland T."Tom" Taylor
> President
> Thermogenics Inc.
> 7100-F 2nd St. NW Albuquerque, NM 87107
> Phone:505-463-8422 Fax:505-268-9206 (call first)
> Web: thermogenics.com
>
>
>
> **************************************
> See what's new at http://www.aol.com
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
>
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
>
>
>
> --
>
>
----------------------------------------------------------------------------
----
> jim mason
> website: www.whatiamupto.com
> current project: mechabolic ( http://www.mechabolic.org)
> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
>
--
----------------------------------------------------------------------------
----
jim mason
website: www.whatiamupto.com
current project: mechabolic (http://www.mechabolic.org)
announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
------------------------------
Message: 3
Date: Sun, 28 Oct 2007 12:44:46 -0700
From: "Art Krenzel" <phoenix98604 at msn.com>
Subject: [Gasification] Two stage gasification
To: "Discussion of biomass pyrolysis and gasification"
<gasification at listserv.repp.org>
Message-ID: <BAY108-DAV50C06FC2AF38E55715CB39B900 at phx.gbl>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Jim and others.
The Danes have been doing high quality two stage gasification for years.
Just GOOGLE two stage gasification Technical University of Denmark and you
will get more information on high quality gas producing , simple to operate
gasifiers than you will ever want.
Let us not re-invent the wheel here or make high quality gas seem like an
impossibility.
Art Krenzel
----- Original Message -----
From: "jim mason" <jimmason at whatiamupto.com>
To: "Mark Ludlow" <mark at ludlow.com>
Cc: <gasification at listserv.repp.org>
Sent: Sunday, October 28, 2007 12:31 PM
Subject: Re: [Gasification] combustion of tarry producer gas
> On 10/27/07, Mark Ludlow <mark at ludlow.com> wrote:
>>
>> I agree, in priciple. But the challenge for widespread application of
>> gasification demands that small-unit applications not be fuel sensitive.
>> (Who wouldn't love to have almond shells to run?) Face it: an updraft
>> gasifier where fuel can be dumped on a reactive bed is the simplest
>> scenario. Sure, it takes no advantage of passing the pyrolyzed gas
>> through a
>> cracking zone. But I have a sneaking suspicion that combining all
>> requirements of tar-free gasification in a single device may not be the
>> most
>> practical solution in all instances (my apologies to Doug Williams). It's
>> certainly more elegant to have a single chamber doing gasification and
>> cracking but who would refuse access to a fuel source composed of only
>> charcoal even if, lb-for-lb, its HHV was less than properly-sized dry
>> biomass? Everyone would rather avoid tar from the outset by having pure C
>> as
>> a fuel (in an ideal world). But is it possible to "close-couple"
>> gasification and tar cracking without making them integral to a single
>> process?
>>
>
> i apologize if i created the impression that i think updrafts are off the
> table. of course there are many applications and subprocess needs where
> an
> updraft is well suited. the requirements for dealing with the output gas
> can be complicated if more than an immediate close coupled burn, without
> passing through a fan.
>
> mark is correct that a great attraction of an updraft is its fuel
> flexibility. as the air/gasflow is going in the opposite direction of
> gravity, they are much less likely to cake up. higher moistures will only
> degrade the energy in the product gas, but not stop the gasifier from
> working, like in a downdraft.
>
> at this point i don't find any single vessel solution to be able to
> adequately process fuels with the needed flexibility for tolerable real
> operation, and produce a consistent tar free gas. the self regulating
> simplicity of combustion against reduction, with radiated/conection heat
> running pyrolysis, in a single vessel is elegant in its minimalism, but it
> is famoustly difficult to control. the self-regulating character of these
> single vessel solutions only work within a very narrow band of fuel and
> air
> humidity conditions. i find the world to not easily provide these
> conditions. thus most gasification efforts become fuel standardization
> efforts. and very few survive this transformation.
>
> most all my work towards fuel agnostic, tar free gasifiers, is moving
> towards pulling each of the zones apart and contending with them
> separately,
> either in dedicated and well separated spaces in a "single vessel", or a
> fully separate dedicated vessel. the processes can then be recombined and
> controlled actively with microprocessors so that the great variation in
> performance as fuel changes, can be compensated for in real time. i don't
> have a finished system yet, but i'm going as fast as i can.
>
> such gasifiers cannot be built from junk quite so easily, but they also
> hold
> the potential to actually work in real world conditions.
>
> for inspiration, i keep a large dumpster bin of real world organic matter
> outside my shop. it has the waste of the world in it that i think a
> gasifier should be able to deal with: mixed construction waste with nails,
> plastic cups, newspaper, cardboard boxes, dimensioned lumber, coffee,
> brush
> clippings, tires, water bottles, etc etc etc. i stare at this pile daily
> to
> remind myself of the range of what a gasifier needs to be able to intake
> to
> actually fulfill its promise of "energy from any waste biomass"
>
> right now we are mostly at "energy from very carefully preprocessed forms
> of
> organic waste, handled with such care and knowledge, that they are really
> a
> high grade fuel again before they go in the gasifier". and thus is why so
> few current small scale gasfiier installations ever work in the end. the
> limitations of fuel type and condition, as well as expertise required to
> maintain these conditions, is not reasonable for typical users.
>
> we are not going to solve this problem with any minor tweak to an imbert
> type. but i think we can solve it by the thoughtful separation and
> control
> of the subprocesses, with active embedded control for recombining the
> parts
> and flows between them. this will result in hybrid systems that have
> combinations of various "traditional" types into a single system. and
> yes,
> updrafts might be quite important as subprocesses in such a system.
>
> j
>
>
>
>
>
>
>
>
>
>
>
>
>
> Rex Z. has expressed a vision of a dual-zone reactor. Few experimenters or
>> small-scale devotees are likely to attempt the fluid bed model that he
>> describes, but a critical notion is the physical division of gasification
>> and 'refinement' within a continuous flow stream. In its simplest
>> expression, optimizing a primary generator to become an efficient
>> converter
>> of solid feed substrate to gas is one task; and providing the environment
>> to
>> reduce this gas to short-chain combustible components becomes the second
>> task.
>>
>>
>>
>> Gasification, in its present popular incarnation, assumes that cracking
>> of
>> tarry gas requires a parasitic process deriving energy from the primary
>> reaction zone. This is very elegant, in theory, but is dependent on a
>> number
>> of mechanical parameters such as fuel condition and form factor. I ask:
>> cannot the tars from a simple updraft gasifier be considered a fuel
>> source
>> unto themselves? Between their gaseous state and their troublesome
>> crystallized state there must be a liquid state that would facilitate
>> their
>> transport back into either the primary gasification/reduction zone or a
>> secondary oxidation zone, providing energy for the primary gasification
>> transformation.
>>
>>
>>
>> Am I dreaming?
>>
>>
>>
>> Mark
>>
>>
>>
>> *From:* jimmmason at gmail.com [mailto:jimmmason at gmail.com] *On Behalf Of
>> *jim
>> mason
>> *Sent:* Saturday, October 27, 2007 12:27 AM
>> *To:* mark at ludlow.com; Discussion of biomass pyrolysis and gasification
>> *Subject:* Re: [Gasification] combustion of tarry producer gas
>>
>>
>>
>>
>>
>> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:Tom,
>> What do you estimate that the temperature of condensation of typical
>> woodgas
>> tar is?
>> Mark
>> --------------------------
>>
>> this is commonly desciribed as above 350degC
>>
>> but really, there is a tremendous variation between primary, secondary
>> and
>> tertiary tars. or light and heavy. depending how terms are defined.
>>
>> leland has much more experience in long running installation than i and
>> many others here. my knowledge is only from running prototype rigs to
>> date. so in general, i defer to leland and other like experienced elders
>> in
>> this endeavor.
>>
>> so yes, avoid updraft gasifiers with biomass at nearly all costs. make
>> clean gas from the begininng. innumerable problems will be less onerous
>> downstream if you do so.
>>
>> jim
>>
>>
>> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:
>>
>> Tom,
>> What do you estimate that the temperature of condensation of typical
>> woodgas
>> tar is?
>> Mark
>>
>> -----Original Message-----
>> From: gasification-bounces at listserv.repp.org
>> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of
>> LINVENT at aol.com
>> Sent: Friday, October 26, 2007 10:35 PM
>> To: jimmason at whatiamupto.com; gasification at listserv.repp.org
>> Subject: Re: [Gasification] combustion of tarry producer gas
>>
>> Burning tarry producer gas may appear to be an easy job, but after a
>> while
>> there are problems with it. One is that the tars may crack around the hot
>> combustion areas and carbon up the pipes, ports apertures or other parts
>> exposed to
>> the direct or indirect heat from the combustion of the gas. Tars will
>> condense
>> anywhere in the transport pipes. Once condensed, they will solidify over
>> time
>> and block the pipes. They also drip off the end of the combustion pipe
>> into
>> the combustion chamber and pile up or burn within the chamber. If any
>> long
>> term
>> usage of them is expected without significant pipe cleaning downtime, the
>> gas
>> needs to be clean.
>>
>>
>>
>> Sincerely,
>> Leland T. Taylor
>> Leland T."Tom" Taylor
>> President
>> Thermogenics Inc.
>> 7100-F 2nd St. NW Albuquerque, NM 87107
>> Phone:505-463-8422 Fax:505-268-9206 (call first)
>> Web: thermogenics.com
>>
>>
>>
>> **************************************
>> See what's new at http://www.aol.com
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>>
>>
>> --
>>
>>
----------------------------------------------------------------------------
----
>> jim mason
>> website: www.whatiamupto.com
>> current project: mechabolic ( http://www.mechabolic.org)
>> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
>>
>
>
>
> --
>
----------------------------------------------------------------------------
----
> jim mason
> website: www.whatiamupto.com
> current project: mechabolic (http://www.mechabolic.org)
> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
------------------------------
Message: 4
Date: Sun, 28 Oct 2007 12:54:25 -0700
From: "Tom Miles" <tmiles at trmiles.com>
Subject: Re: [Gasification] Two stage gasification
To: "'Discussion of biomass pyrolysis and gasification'"
<gasification at listserv.repp.org>
Message-ID: <000301c8199c$57de5400$079afc00$@com>
Content-Type: text/plain; charset="us-ascii"
See http://www.bgg.mek.dtu.dk/
Publications: http://www.bgg.mek.dtu.dk/Publications.aspx (Note some links
are not functional. I have notified them.)
Tom
-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of Art Krenzel
Sent: Sunday, October 28, 2007 12:45 PM
To: Discussion of biomass pyrolysis and gasification
Subject: [Gasification] Two stage gasification
Jim and others.
The Danes have been doing high quality two stage gasification for years.
Just GOOGLE two stage gasification Technical University of Denmark and you
will get more information on high quality gas producing , simple to operate
gasifiers than you will ever want.
Let us not re-invent the wheel here or make high quality gas seem like an
impossibility.
Art Krenzel
----- Original Message -----
From: "jim mason" <jimmason at whatiamupto.com>
To: "Mark Ludlow" <mark at ludlow.com>
Cc: <gasification at listserv.repp.org>
Sent: Sunday, October 28, 2007 12:31 PM
Subject: Re: [Gasification] combustion of tarry producer gas
> On 10/27/07, Mark Ludlow <mark at ludlow.com> wrote:
>>
>> I agree, in priciple. But the challenge for widespread application of
>> gasification demands that small-unit applications not be fuel sensitive.
>> (Who wouldn't love to have almond shells to run?) Face it: an updraft
>> gasifier where fuel can be dumped on a reactive bed is the simplest
>> scenario. Sure, it takes no advantage of passing the pyrolyzed gas
>> through a
>> cracking zone. But I have a sneaking suspicion that combining all
>> requirements of tar-free gasification in a single device may not be the
>> most
>> practical solution in all instances (my apologies to Doug Williams). It's
>> certainly more elegant to have a single chamber doing gasification and
>> cracking but who would refuse access to a fuel source composed of only
>> charcoal even if, lb-for-lb, its HHV was less than properly-sized dry
>> biomass? Everyone would rather avoid tar from the outset by having pure C
>> as
>> a fuel (in an ideal world). But is it possible to "close-couple"
>> gasification and tar cracking without making them integral to a single
>> process?
>>
>
> i apologize if i created the impression that i think updrafts are off the
> table. of course there are many applications and subprocess needs where
> an
> updraft is well suited. the requirements for dealing with the output gas
> can be complicated if more than an immediate close coupled burn, without
> passing through a fan.
>
> mark is correct that a great attraction of an updraft is its fuel
> flexibility. as the air/gasflow is going in the opposite direction of
> gravity, they are much less likely to cake up. higher moistures will only
> degrade the energy in the product gas, but not stop the gasifier from
> working, like in a downdraft.
>
> at this point i don't find any single vessel solution to be able to
> adequately process fuels with the needed flexibility for tolerable real
> operation, and produce a consistent tar free gas. the self regulating
> simplicity of combustion against reduction, with radiated/conection heat
> running pyrolysis, in a single vessel is elegant in its minimalism, but it
> is famoustly difficult to control. the self-regulating character of these
> single vessel solutions only work within a very narrow band of fuel and
> air
> humidity conditions. i find the world to not easily provide these
> conditions. thus most gasification efforts become fuel standardization
> efforts. and very few survive this transformation.
>
> most all my work towards fuel agnostic, tar free gasifiers, is moving
> towards pulling each of the zones apart and contending with them
> separately,
> either in dedicated and well separated spaces in a "single vessel", or a
> fully separate dedicated vessel. the processes can then be recombined and
> controlled actively with microprocessors so that the great variation in
> performance as fuel changes, can be compensated for in real time. i don't
> have a finished system yet, but i'm going as fast as i can.
>
> such gasifiers cannot be built from junk quite so easily, but they also
> hold
> the potential to actually work in real world conditions.
>
> for inspiration, i keep a large dumpster bin of real world organic matter
> outside my shop. it has the waste of the world in it that i think a
> gasifier should be able to deal with: mixed construction waste with nails,
> plastic cups, newspaper, cardboard boxes, dimensioned lumber, coffee,
> brush
> clippings, tires, water bottles, etc etc etc. i stare at this pile daily
> to
> remind myself of the range of what a gasifier needs to be able to intake
> to
> actually fulfill its promise of "energy from any waste biomass"
>
> right now we are mostly at "energy from very carefully preprocessed forms
> of
> organic waste, handled with such care and knowledge, that they are really
> a
> high grade fuel again before they go in the gasifier". and thus is why so
> few current small scale gasfiier installations ever work in the end. the
> limitations of fuel type and condition, as well as expertise required to
> maintain these conditions, is not reasonable for typical users.
>
> we are not going to solve this problem with any minor tweak to an imbert
> type. but i think we can solve it by the thoughtful separation and
> control
> of the subprocesses, with active embedded control for recombining the
> parts
> and flows between them. this will result in hybrid systems that have
> combinations of various "traditional" types into a single system. and
> yes,
> updrafts might be quite important as subprocesses in such a system.
>
> j
>
>
>
>
>
>
>
>
>
>
>
>
>
> Rex Z. has expressed a vision of a dual-zone reactor. Few experimenters or
>> small-scale devotees are likely to attempt the fluid bed model that he
>> describes, but a critical notion is the physical division of gasification
>> and 'refinement' within a continuous flow stream. In its simplest
>> expression, optimizing a primary generator to become an efficient
>> converter
>> of solid feed substrate to gas is one task; and providing the environment
>> to
>> reduce this gas to short-chain combustible components becomes the second
>> task.
>>
>>
>>
>> Gasification, in its present popular incarnation, assumes that cracking
>> of
>> tarry gas requires a parasitic process deriving energy from the primary
>> reaction zone. This is very elegant, in theory, but is dependent on a
>> number
>> of mechanical parameters such as fuel condition and form factor. I ask:
>> cannot the tars from a simple updraft gasifier be considered a fuel
>> source
>> unto themselves? Between their gaseous state and their troublesome
>> crystallized state there must be a liquid state that would facilitate
>> their
>> transport back into either the primary gasification/reduction zone or a
>> secondary oxidation zone, providing energy for the primary gasification
>> transformation.
>>
>>
>>
>> Am I dreaming?
>>
>>
>>
>> Mark
>>
>>
>>
>> *From:* jimmmason at gmail.com [mailto:jimmmason at gmail.com] *On Behalf Of
>> *jim
>> mason
>> *Sent:* Saturday, October 27, 2007 12:27 AM
>> *To:* mark at ludlow.com; Discussion of biomass pyrolysis and gasification
>> *Subject:* Re: [Gasification] combustion of tarry producer gas
>>
>>
>>
>>
>>
>> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:Tom,
>> What do you estimate that the temperature of condensation of typical
>> woodgas
>> tar is?
>> Mark
>> --------------------------
>>
>> this is commonly desciribed as above 350degC
>>
>> but really, there is a tremendous variation between primary, secondary
>> and
>> tertiary tars. or light and heavy. depending how terms are defined.
>>
>> leland has much more experience in long running installation than i and
>> many others here. my knowledge is only from running prototype rigs to
>> date. so in general, i defer to leland and other like experienced elders
>> in
>> this endeavor.
>>
>> so yes, avoid updraft gasifiers with biomass at nearly all costs. make
>> clean gas from the begininng. innumerable problems will be less onerous
>> downstream if you do so.
>>
>> jim
>>
>>
>> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:
>>
>> Tom,
>> What do you estimate that the temperature of condensation of typical
>> woodgas
>> tar is?
>> Mark
>>
>> -----Original Message-----
>> From: gasification-bounces at listserv.repp.org
>> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of
>> LINVENT at aol.com
>> Sent: Friday, October 26, 2007 10:35 PM
>> To: jimmason at whatiamupto.com; gasification at listserv.repp.org
>> Subject: Re: [Gasification] combustion of tarry producer gas
>>
>> Burning tarry producer gas may appear to be an easy job, but after a
>> while
>> there are problems with it. One is that the tars may crack around the hot
>> combustion areas and carbon up the pipes, ports apertures or other parts
>> exposed to
>> the direct or indirect heat from the combustion of the gas. Tars will
>> condense
>> anywhere in the transport pipes. Once condensed, they will solidify over
>> time
>> and block the pipes. They also drip off the end of the combustion pipe
>> into
>> the combustion chamber and pile up or burn within the chamber. If any
>> long
>> term
>> usage of them is expected without significant pipe cleaning downtime, the
>> gas
>> needs to be clean.
>>
>>
>>
>> Sincerely,
>> Leland T. Taylor
>> Leland T."Tom" Taylor
>> President
>> Thermogenics Inc.
>> 7100-F 2nd St. NW Albuquerque, NM 87107
>> Phone:505-463-8422 Fax:505-268-9206 (call first)
>> Web: thermogenics.com
>>
>>
>>
>> **************************************
>> See what's new at http://www.aol.com
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>>
>>
>> --
>>
>>
----------------------------------------------------------------------------
----
>> jim mason
>> website: www.whatiamupto.com
>> current project: mechabolic ( http://www.mechabolic.org)
>> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
>>
>
>
>
> --
>
----------------------------------------------------------------------------
----
> jim mason
> website: www.whatiamupto.com
> current project: mechabolic (http://www.mechabolic.org)
> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
_______________________________________________
Gasification mailing list
Gasification at listserv.repp.org
http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
http://gasifiers.bioenergylists.org
http://info.bioenergylists.org
------------------------------
Message: 5
Date: Sun, 28 Oct 2007 14:10:33 -0600
From: Bob Stuart <bobstuart at sasktel.net>
Subject: Re: [Gasification] combustion of tarry producer gas
To: Discussion of biomass pyrolysis and gasification
<gasification at listserv.repp.org>
Message-ID: <4E4C45E1-ECB5-445A-9656-0EA01DC29A35 at sasktel.net>
Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
On 28-Oct-07, at 1:31 PM, jim mason wrote:
... the self regulating
> simplicity of combustion against reduction, with radiated/conection
> heat
> running pyrolysis, in a single vessel is elegant in its minimalism,
> but it
> is famoustly difficult to control. the self-regulating character
> of these
> single vessel solutions only work within a very narrow band of fuel
> and air
> humidity conditions. i find the world to not easily provide these
> conditions. thus most gasification efforts become fuel
> standardization
> efforts. and very few survive this transformation.
Primitive steelmaking was a series of steps carried too far, and then
corrected. Perhaps the dream of the single-chamber gasifier could
be realized using the stick-slip conveyor system Drew mentioned to
carry a variety of fuel. The fuel could be over-dried by solar and
waste process heat, and the necessary moisture metered back in. The
system could also react to variations in fuel by adjusting the
location and temperature of air for combustion. The conveyor might
also perform useful agitating and/or scraping actions.
Best,
Bob Stuart
------------------------------
Message: 6
Date: Sun, 28 Oct 2007 15:45:22 -0600
From: Thomas Reed <tombreed at comcast.net>
Subject: [Gasification] Cigarette gasifiers and CO
To: Discussion of biomass pyrolysis and gasification
<gasification at listserv.repp.org>
Message-ID: <472502F2.9060407 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Jim Mason and All:
According to OSHA
(http://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdf)
you can live with 50 ppm CO all day, so the 10-20 ppm exhaled by
cigarette smokers is not dangerous. (My mother lived to 90 and smoked
until 80). The danger of CO poisoning can be overrated, but we have a
chapter on it in our gasification handbook and it can also interfere
with your SEX life.
We regularly explain the difference between DD and TLUD gasification to
guests by sucking (conventional downdraft)/blowing (TLUD). The 5 kW
gasifier link below is inoperative, but we regularly demonstrate the
TLUD cigarette/cigar gasifier using a lungful of pure oxygen (from a
cutting torch etc.) to get a 6" flame by blowing through the lit
cig/cig. We also demonstrate DD gasification by putting the lit end in
our mouth and blowing, resulting in clouds of dense white smoke. But I
wouldn't try it with oxygen - the flame could travel back into your mouth.
Onward, gasward,
TOM REED BEF
jim mason wrote:
>>> Hi all,
>>>
>>> I am puzzled by an apparent contradiction: why is the CO content of
>>> cigarette smoke so low (~3 - see below), in comparison to typical
>>> biomass updraft gasifier gas (10-20)?
>>>
>>>
>
> yes, a cigarette is an updraft gasifier (assuming you are smoking it
> the normal way). if you put the lit butt in your mouth and suck, then
> you are smoking a stratified downdraft. should make more CO, but less
> tar.
>
> for those who havne't seen it, last year we made a small 5kw genset
> run on cigarettes. 6 packs lasted less than a minute:
>
> http://www.whatiamupto.com/gasification/cigifier.htm
>
> in a cigarette the CO is likely low because the temp is low and/or the
> equivalency ratio is low. remember that different produced gases peak
> in their production at different temps in thermal biomass degradation.
> CO is the highest before full combustion and CO2.
>
> there is a great chart on this in the biomass thermal conversion ency
> from BEF. the order of peaks, from atm temp to full combustion, is:
> CH4, H2, CO, CO2. such is why a low temp gasifier will have more H2.
> or a pyrolyser will have even more. and by small extension, with the
> help of microbes, anerobic digestion is highest in CH4
>
> but yes, as i learned about what is happening in gasification, i
> became amazed that cigarettes do not immediately kill us. not so much
> the CO, which is important, but rather all the HCs that come out at
> the same time. namely the tars. one could not better design a direct
> HC tar delivery system than a cigarette.
>
> that our body can deal with it speaks to our general ability to
> process relatively high levels of organic chemicals. my guess is
> that we likely evolved this ability given the importance of fire in
> our history. through the use of open flame for heating and cooking,
> we create and consume huge amounts of nasty organic chemicals. even
> bbq beef is a tar sandwich.
>
> can i get a toulene spritzer with my vodka and tonic, please?
>
> j
>
>
>
>
>
>
> j
>
>
>
>
>>> A cigarette seems to me to be an updraft biomass gasifier, in every way.
>>> (it is a very small scale one, and the combustion zone is both
>>> unshielded and uninsulated, so it might have proportionately huge heat
>>> losses).
>>>
>> Hello Daniel,
>> I think a cigarette is more a combustor than a gasifier because the
tobacco
>> is not densely packed and there is enough space for sufficient air flow.
>> Philippe.
>>
>>
>>
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>
>
>
------------------------------
Message: 7
Date: Sun, 28 Oct 2007 18:59:18 -0700
From: "jim mason" <jimmason at whatiamupto.com>
Subject: Re: [Gasification] Cigarette gasifiers and CO
To: "Discussion of biomass pyrolysis and gasification"
<gasification at listserv.repp.org>
Message-ID:
<31a4f6f00710281859j12901af3kcdee81128ba57ae3 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
On 10/28/07, Thomas Reed <tombreed at comcast.net> wrote:
>
> Jim Mason and All:
>
> According to OSHA
> (
> http://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdf
> )
> you can live with 50 ppm CO all day, so the 10-20 ppm exhaled by
> cigarette smokers is not dangerous.
well i'm glad they are removing it to their hemoglobin so the exhale is
relatively CO free . . . ;-). cigarette smoke inward is surely more than
10-20ppm CO
We regularly explain the difference between DD and TLUD gasification to
> guests by sucking (conventional downdraft)/blowing (TLUD). The 5 kW
> gasifier link below is inoperative,
sorry, i copied it incorrectly. the cigarette gasifier to briggs and
stratten engine stunt is here. not suggested for tar free gas making . . .
http://www.whatiamupto.com/gasification/cigifier/index.htm
j
but we regularly demonstrate the
> TLUD cigarette/cigar gasifier using a lungful of pure oxygen (from a
> cutting torch etc.) to get a 6" flame by blowing through the lit
> cig/cig. We also demonstrate DD gasification by putting the lit end in
> our mouth and blowing, resulting in clouds of dense white smoke. But I
> wouldn't try it with oxygen - the flame could travel back into your mouth.
>
> Onward, gasward,
>
> TOM REED BEF
>
> jim mason wrote:
> >>> Hi all,
> >>>
> >>> I am puzzled by an apparent contradiction: why is the CO content of
> >>> cigarette smoke so low (~3 - see below), in comparison to typical
> >>> biomass updraft gasifier gas (10-20)?
> >>>
> >>>
> >
> > yes, a cigarette is an updraft gasifier (assuming you are smoking it
> > the normal way). if you put the lit butt in your mouth and suck, then
> > you are smoking a stratified downdraft. should make more CO, but less
> > tar.
> >
> > for those who havne't seen it, last year we made a small 5kw genset
> > run on cigarettes. 6 packs lasted less than a minute:
> >
> > http://www.whatiamupto.com/gasification/cigifier.htm
> >
> > in a cigarette the CO is likely low because the temp is low and/or the
> > equivalency ratio is low. remember that different produced gases peak
> > in their production at different temps in thermal biomass degradation.
> > CO is the highest before full combustion and CO2.
> >
> > there is a great chart on this in the biomass thermal conversion ency
> > from BEF. the order of peaks, from atm temp to full combustion, is:
> > CH4, H2, CO, CO2. such is why a low temp gasifier will have more H2.
> > or a pyrolyser will have even more. and by small extension, with the
> > help of microbes, anerobic digestion is highest in CH4
> >
> > but yes, as i learned about what is happening in gasification, i
> > became amazed that cigarettes do not immediately kill us. not so much
> > the CO, which is important, but rather all the HCs that come out at
> > the same time. namely the tars. one could not better design a direct
> > HC tar delivery system than a cigarette.
> >
> > that our body can deal with it speaks to our general ability to
> > process relatively high levels of organic chemicals. my guess is
> > that we likely evolved this ability given the importance of fire in
> > our history. through the use of open flame for heating and cooking,
> > we create and consume huge amounts of nasty organic chemicals. even
> > bbq beef is a tar sandwich.
> >
> > can i get a toulene spritzer with my vodka and tonic, please?
> >
> > j
> >
> >
> >
> >
> >
> >
> > j
> >
> >
> >
> >
> >>> A cigarette seems to me to be an updraft biomass gasifier, in every
> way.
> >>> (it is a very small scale one, and the combustion zone is both
> >>> unshielded and uninsulated, so it might have proportionately huge heat
> >>> losses).
> >>>
> >> Hello Daniel,
> >> I think a cigarette is more a combustor than a gasifier because the
> tobacco
> >> is not densely packed and there is enough space for sufficient air
> flow.
> >> Philippe.
> >>
> >>
> >>
> >> _______________________________________________
> >> Gasification mailing list
> >> Gasification at listserv.repp.org
> >>
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> >> http://gasifiers.bioenergylists.org
> >> http://info.bioenergylists.org
> >>
> >>
> >
> >
> >
>
>
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
--
----------------------------------------------------------------------------
----
jim mason
website: www.whatiamupto.com
current project: mechabolic (http://www.mechabolic.org)
announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
------------------------------
Message: 8
Date: Sun, 28 Oct 2007 22:14:00 -0700
From: "Malcolm Lefcort" <mlefcort at shaw.ca>
Subject: [Gasification] FW: Gasification Digest, Vol 16, Issue 27
To: "'Discussion of biomass pyrolysis and gasification'"
<gasification at listserv.repp.org>
Message-ID: <000001c819ea$845788f0$8d069ad0$@ca>
Content-Type: text/plain; charset="us-ascii"
Re: Tars, etc.
As you well know, Tom, we can make like the Swedes and dry, scrub, clean up,
and then pulverize, initially wet, dirty biomass, before gasifying it.
That's pretty straight forward. Unfortunately, it is extremely costly.
I don't know how many millions (billions?) of Euros were spent on the
pulverized wood gasification gas turbine project installed, deep
underground, in downtown Stockholm (or so I'm told); the cold, clean
producer gas from which is burned in a specially designed (?) gas turbine
combustion chamber. Very interesting from a technical point of view; very
impractical from an economic point of view.
As far as I'm concerned, the only way to use biomass to make gas turbine
generated power is to do so indirectly: by using an external heat exchanger.
The heat exchanger replaces the combustion chamber.
Products of combustion from a two-stage combustor - oops, a gasifier cum
thermal oxidizer - such as the Heuristic EnvirOcycler, are routed through
the shell side of the external heat exchanger. Compressor discharge air
travels through the tube side of the heat exchanger. A piece of cake.
See "Sawmill, Wood Waste Fuelled, 100% Recuperated, 5 MWe Gas Turbine
Co-Generation Plant", International Gas Turbine & Aeroengine Congress &
Exhibition, Stockholm, Sweden, 2nd - 5th June 1998, ASME Paper 98-GT-62.
See http://www.heuristicengineering.com/papers/papers.html
Malcolm Lefcort
Heuristic Engineering Inc
Vancouver, BC
-----Original Message-----
From: gasification-bounces at listserv.repp.org
Sent: Sunday, October 28, 2007 8:00 AM
Today's Topics:
1. Re: combustion of tarry producer gas (Tom Miles)
2. Re: combustion of tarry producer gas (Mark Ludlow)
3. Re: combustion of tarry producer gas (Paul S. Anderson)
4. TLUD and Conventional updraft gasifiers (Thomas Reed)
----------------------------------------------------------------------
Message: 1
Date: Sat, 27 Oct 2007 09:27:06 -0700
From: "Tom Miles" <tmiles at trmiles.com>
Subject: Re: [Gasification] combustion of tarry producer gas
To: "'Discussion of biomass pyrolysis and gasification'"
<gasification at listserv.repp.org>
Message-ID: <001601c818b6$36eac850$a4c058f0$@com>
Content-Type: text/plain; charset="us-ascii"
Mark,
Nexterra, the newest industrial scale gasifier in North America, is working
on tar reduction for engine applications at their 8 MMBtuh pilot facility in
Kamloops, British Columbia. I suspect, however, that their solution will be
partial oxidation which burns gases to crack tars, not burning tars to
enhance gasification, which I think you are suggesting.
http://gasifiers.bioenergylists.org/
http://gasifiers.bioenergylists.org/nexterraenergy
Tom
> Gasification, in its present popular incarnation, assumes that
> cracking of tarry gas requires a parasitic process deriving energy
> from the primary reaction zone. This is very elegant, in theory, but
> is dependent on a number of mechanical parameters such as fuel
> condition and form factor. I ask:
> cannot the tars from a simple updraft gasifier be considered a fuel
> source unto themselves? Between their gaseous state and their
> troublesome crystallized state there must be a liquid state that would
> facilitate their transport back into either the primary
> gasification/reduction zone or a secondary oxidation zone, providing
> energy for the primary gasification transformation.
>
>
>
> Am I dreaming?
------------------------------
Message: 9
Date: Sun, 28 Oct 2007 22:43:47 -0700
From: "Mark Ludlow" <mark at ludlow.com>
Subject: Re: [Gasification] FW: Gasification Digest, Vol 16, Issue 27
To: "'Discussion of biomass pyrolysis and gasification'"
<gasification at listserv.repp.org>
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Is this the so-called Ericsson Cyle?
-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of Malcolm Lefcort
Sent: Sunday, October 28, 2007 10:14 PM
To: 'Discussion of biomass pyrolysis and gasification'
Subject: [Gasification] FW: Gasification Digest, Vol 16, Issue 27
Re: Tars, etc.
As you well know, Tom, we can make like the Swedes and dry, scrub, clean up,
and then pulverize, initially wet, dirty biomass, before gasifying it.
That's pretty straight forward. Unfortunately, it is extremely costly.
I don't know how many millions (billions?) of Euros were spent on the
pulverized wood gasification gas turbine project installed, deep
underground, in downtown Stockholm (or so I'm told); the cold, clean
producer gas from which is burned in a specially designed (?) gas turbine
combustion chamber. Very interesting from a technical point of view; very
impractical from an economic point of view.
As far as I'm concerned, the only way to use biomass to make gas turbine
generated power is to do so indirectly: by using an external heat exchanger.
The heat exchanger replaces the combustion chamber.
Products of combustion from a two-stage combustor - oops, a gasifier cum
thermal oxidizer - such as the Heuristic EnvirOcycler, are routed through
the shell side of the external heat exchanger. Compressor discharge air
travels through the tube side of the heat exchanger. A piece of cake.
See "Sawmill, Wood Waste Fuelled, 100% Recuperated, 5 MWe Gas Turbine
Co-Generation Plant", International Gas Turbine & Aeroengine Congress &
Exhibition, Stockholm, Sweden, 2nd - 5th June 1998, ASME Paper 98-GT-62.
See http://www.heuristicengineering.com/papers/papers.html
Malcolm Lefcort
Heuristic Engineering Inc
Vancouver, BC
-----Original Message-----
From: gasification-bounces at listserv.repp.org
Sent: Sunday, October 28, 2007 8:00 AM
Today's Topics:
1. Re: combustion of tarry producer gas (Tom Miles)
2. Re: combustion of tarry producer gas (Mark Ludlow)
3. Re: combustion of tarry producer gas (Paul S. Anderson)
4. TLUD and Conventional updraft gasifiers (Thomas Reed)
----------------------------------------------------------------------
Message: 1
Date: Sat, 27 Oct 2007 09:27:06 -0700
From: "Tom Miles" <tmiles at trmiles.com>
Subject: Re: [Gasification] combustion of tarry producer gas
To: "'Discussion of biomass pyrolysis and gasification'"
<gasification at listserv.repp.org>
Message-ID: <001601c818b6$36eac850$a4c058f0$@com>
Content-Type: text/plain; charset="us-ascii"
Mark,
Nexterra, the newest industrial scale gasifier in North America, is working
on tar reduction for engine applications at their 8 MMBtuh pilot facility in
Kamloops, British Columbia. I suspect, however, that their solution will be
partial oxidation which burns gases to crack tars, not burning tars to
enhance gasification, which I think you are suggesting.
http://gasifiers.bioenergylists.org/
http://gasifiers.bioenergylists.org/nexterraenergy
Tom
> Gasification, in its present popular incarnation, assumes that
> cracking of tarry gas requires a parasitic process deriving energy
> from the primary reaction zone. This is very elegant, in theory, but
> is dependent on a number of mechanical parameters such as fuel
> condition and form factor. I ask:
> cannot the tars from a simple updraft gasifier be considered a fuel
> source unto themselves? Between their gaseous state and their
> troublesome crystallized state there must be a liquid state that would
> facilitate their transport back into either the primary
> gasification/reduction zone or a secondary oxidation zone, providing
> energy for the primary gasification transformation.
>
>
>
> Am I dreaming?
_______________________________________________
Gasification mailing list
Gasification at listserv.repp.org
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------------------------------
Message: 10
Date: Sun, 28 Oct 2007 23:24:57 -0700
From: "Mark Ludlow" <mark at ludlow.com>
Subject: Re: [Gasification] Two stage gasification
To: "'Discussion of biomass pyrolysis and gasification'"
<gasification at listserv.repp.org>
Message-ID: <006d01c819f4$6e4c7c00$4ae57400$@com>
Content-Type: text/plain; charset="us-ascii"
Art,
Thanks for the indulgent response. But do you know of a specific link that
shows a small-scale embodiment of the two-stage concept?
My mind--rightly or wrongly--is stuck on the notion of an updraft pyrolyzer
(equivalent to a reboiler in a distillation column) and progressive
condensation zones and recycle loops that avoid ever having to deal with
tars in a crystallized state; recycling them through the O2-lean pyrolysis
zone until they finally emerge as low-boiling point alkanes along with the
non-condensible CO and H2.
Likely I'm missing something terribly obvious, huh?
Mark
-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of Art Krenzel
Sent: Sunday, October 28, 2007 12:45 PM
To: Discussion of biomass pyrolysis and gasification
Subject: [Gasification] Two stage gasification
Jim and others.
The Danes have been doing high quality two stage gasification for years.
Just GOOGLE two stage gasification Technical University of Denmark and you
will get more information on high quality gas producing , simple to operate
gasifiers than you will ever want.
Let us not re-invent the wheel here or make high quality gas seem like an
impossibility.
Art Krenzel
----- Original Message -----
From: "jim mason" <jimmason at whatiamupto.com>
To: "Mark Ludlow" <mark at ludlow.com>
Cc: <gasification at listserv.repp.org>
Sent: Sunday, October 28, 2007 12:31 PM
Subject: Re: [Gasification] combustion of tarry producer gas
> On 10/27/07, Mark Ludlow <mark at ludlow.com> wrote:
>>
>> I agree, in priciple. But the challenge for widespread application of
>> gasification demands that small-unit applications not be fuel sensitive.
>> (Who wouldn't love to have almond shells to run?) Face it: an updraft
>> gasifier where fuel can be dumped on a reactive bed is the simplest
>> scenario. Sure, it takes no advantage of passing the pyrolyzed gas
>> through a
>> cracking zone. But I have a sneaking suspicion that combining all
>> requirements of tar-free gasification in a single device may not be the
>> most
>> practical solution in all instances (my apologies to Doug Williams). It's
>> certainly more elegant to have a single chamber doing gasification and
>> cracking but who would refuse access to a fuel source composed of only
>> charcoal even if, lb-for-lb, its HHV was less than properly-sized dry
>> biomass? Everyone would rather avoid tar from the outset by having pure C
>> as
>> a fuel (in an ideal world). But is it possible to "close-couple"
>> gasification and tar cracking without making them integral to a single
>> process?
>>
>
> i apologize if i created the impression that i think updrafts are off the
> table. of course there are many applications and subprocess needs where
> an
> updraft is well suited. the requirements for dealing with the output gas
> can be complicated if more than an immediate close coupled burn, without
> passing through a fan.
>
> mark is correct that a great attraction of an updraft is its fuel
> flexibility. as the air/gasflow is going in the opposite direction of
> gravity, they are much less likely to cake up. higher moistures will only
> degrade the energy in the product gas, but not stop the gasifier from
> working, like in a downdraft.
>
> at this point i don't find any single vessel solution to be able to
> adequately process fuels with the needed flexibility for tolerable real
> operation, and produce a consistent tar free gas. the self regulating
> simplicity of combustion against reduction, with radiated/conection heat
> running pyrolysis, in a single vessel is elegant in its minimalism, but it
> is famoustly difficult to control. the self-regulating character of these
> single vessel solutions only work within a very narrow band of fuel and
> air
> humidity conditions. i find the world to not easily provide these
> conditions. thus most gasification efforts become fuel standardization
> efforts. and very few survive this transformation.
>
> most all my work towards fuel agnostic, tar free gasifiers, is moving
> towards pulling each of the zones apart and contending with them
> separately,
> either in dedicated and well separated spaces in a "single vessel", or a
> fully separate dedicated vessel. the processes can then be recombined and
> controlled actively with microprocessors so that the great variation in
> performance as fuel changes, can be compensated for in real time. i don't
> have a finished system yet, but i'm going as fast as i can.
>
> such gasifiers cannot be built from junk quite so easily, but they also
> hold
> the potential to actually work in real world conditions.
>
> for inspiration, i keep a large dumpster bin of real world organic matter
> outside my shop. it has the waste of the world in it that i think a
> gasifier should be able to deal with: mixed construction waste with nails,
> plastic cups, newspaper, cardboard boxes, dimensioned lumber, coffee,
> brush
> clippings, tires, water bottles, etc etc etc. i stare at this pile daily
> to
> remind myself of the range of what a gasifier needs to be able to intake
> to
> actually fulfill its promise of "energy from any waste biomass"
>
> right now we are mostly at "energy from very carefully preprocessed forms
> of
> organic waste, handled with such care and knowledge, that they are really
> a
> high grade fuel again before they go in the gasifier". and thus is why so
> few current small scale gasfiier installations ever work in the end. the
> limitations of fuel type and condition, as well as expertise required to
> maintain these conditions, is not reasonable for typical users.
>
> we are not going to solve this problem with any minor tweak to an imbert
> type. but i think we can solve it by the thoughtful separation and
> control
> of the subprocesses, with active embedded control for recombining the
> parts
> and flows between them. this will result in hybrid systems that have
> combinations of various "traditional" types into a single system. and
> yes,
> updrafts might be quite important as subprocesses in such a system.
>
> j
>
>
>
>
>
>
>
>
>
>
>
>
>
> Rex Z. has expressed a vision of a dual-zone reactor. Few experimenters or
>> small-scale devotees are likely to attempt the fluid bed model that he
>> describes, but a critical notion is the physical division of gasification
>> and 'refinement' within a continuous flow stream. In its simplest
>> expression, optimizing a primary generator to become an efficient
>> converter
>> of solid feed substrate to gas is one task; and providing the environment
>> to
>> reduce this gas to short-chain combustible components becomes the second
>> task.
>>
>>
>>
>> Gasification, in its present popular incarnation, assumes that cracking
>> of
>> tarry gas requires a parasitic process deriving energy from the primary
>> reaction zone. This is very elegant, in theory, but is dependent on a
>> number
>> of mechanical parameters such as fuel condition and form factor. I ask:
>> cannot the tars from a simple updraft gasifier be considered a fuel
>> source
>> unto themselves? Between their gaseous state and their troublesome
>> crystallized state there must be a liquid state that would facilitate
>> their
>> transport back into either the primary gasification/reduction zone or a
>> secondary oxidation zone, providing energy for the primary gasification
>> transformation.
>>
>>
>>
>> Am I dreaming?
>>
>>
>>
>> Mark
>>
>>
>>
>> *From:* jimmmason at gmail.com [mailto:jimmmason at gmail.com] *On Behalf Of
>> *jim
>> mason
>> *Sent:* Saturday, October 27, 2007 12:27 AM
>> *To:* mark at ludlow.com; Discussion of biomass pyrolysis and gasification
>> *Subject:* Re: [Gasification] combustion of tarry producer gas
>>
>>
>>
>>
>>
>> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:Tom,
>> What do you estimate that the temperature of condensation of typical
>> woodgas
>> tar is?
>> Mark
>> --------------------------
>>
>> this is commonly desciribed as above 350degC
>>
>> but really, there is a tremendous variation between primary, secondary
>> and
>> tertiary tars. or light and heavy. depending how terms are defined.
>>
>> leland has much more experience in long running installation than i and
>> many others here. my knowledge is only from running prototype rigs to
>> date. so in general, i defer to leland and other like experienced elders
>> in
>> this endeavor.
>>
>> so yes, avoid updraft gasifiers with biomass at nearly all costs. make
>> clean gas from the begininng. innumerable problems will be less onerous
>> downstream if you do so.
>>
>> jim
>>
>>
>> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:
>>
>> Tom,
>> What do you estimate that the temperature of condensation of typical
>> woodgas
>> tar is?
>> Mark
>>
>> -----Original Message-----
>> From: gasification-bounces at listserv.repp.org
>> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of
>> LINVENT at aol.com
>> Sent: Friday, October 26, 2007 10:35 PM
>> To: jimmason at whatiamupto.com; gasification at listserv.repp.org
>> Subject: Re: [Gasification] combustion of tarry producer gas
>>
>> Burning tarry producer gas may appear to be an easy job, but after a
>> while
>> there are problems with it. One is that the tars may crack around the hot
>> combustion areas and carbon up the pipes, ports apertures or other parts
>> exposed to
>> the direct or indirect heat from the combustion of the gas. Tars will
>> condense
>> anywhere in the transport pipes. Once condensed, they will solidify over
>> time
>> and block the pipes. They also drip off the end of the combustion pipe
>> into
>> the combustion chamber and pile up or burn within the chamber. If any
>> long
>> term
>> usage of them is expected without significant pipe cleaning downtime, the
>> gas
>> needs to be clean.
>>
>>
>>
>> Sincerely,
>> Leland T. Taylor
>> Leland T."Tom" Taylor
>> President
>> Thermogenics Inc.
>> 7100-F 2nd St. NW Albuquerque, NM 87107
>> Phone:505-463-8422 Fax:505-268-9206 (call first)
>> Web: thermogenics.com
>>
>>
>>
>> **************************************
>> See what's new at http://www.aol.com
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>> _______________________________________________
>> Gasification mailing list
>> Gasification at listserv.repp.org
>> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
>> http://gasifiers.bioenergylists.org
>> http://info.bioenergylists.org
>>
>>
>>
>>
>> --
>>
>>
----------------------------------------------------------------------------
----
>> jim mason
>> website: www.whatiamupto.com
>> current project: mechabolic ( http://www.mechabolic.org)
>> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
>>
>
>
>
> --
>
----------------------------------------------------------------------------
----
> jim mason
> website: www.whatiamupto.com
> current project: mechabolic (http://www.mechabolic.org)
> announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
> http://info.bioenergylists.org
>
_______________________________________________
Gasification mailing list
Gasification at listserv.repp.org
http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
http://gasifiers.bioenergylists.org
http://info.bioenergylists.org
------------------------------
Message: 11
Date: Mon, 29 Oct 2007 00:45:41 -0700 (PDT)
From: Pasidu Pallawela <pasidup at yahoo.com>
Subject: [Gasification] Wood Cubes from Saw Dust
To: gasification at listserv.repp.org
Message-ID: <848192.86065.qm at web33212.mail.mud.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1
Dear All,
I would be pleased if any one of you gentlemen could help me in finding a
method to compress saw dust or wood chips in to cubes or pellets. I have
explained my actual requirement in detail below.
I'm voluntarily helping a NGO in Sri Lanka called "Energy Forum" which
provide basic power needs to rural areas. They have donated several small
scale gasifiers built in several rural villages and we found recently that
the villagers are engaged in cutting down the forest in order to feed their
gasifiers. We educated them about the bad effects of deforestation and now
we're looking at a method to supply them alternative energy solution via
wood cubes or wood pellets.
Our organization has identified the excess amount of wood chips and saw
dust available in various areas, where we have commercial timber and wood
industry. We need to compress sawdust and to make cubes or pellets out of
it, so they can easily transport them to rural areas.
I would be pleases if some one can explain me the methodology of
compressing and manufacturing cubes out of saw dust or to direct me to a
person or place where I can get more details on this matter.
Thank You,
Best Regards
Pasidu Pallawela
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
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------------------------------
Message: 12
Date: Mon, 29 Oct 2007 01:38:45 -0700
From: "jim mason" <jimmason at whatiamupto.com>
Subject: Re: [Gasification] Two stage gasification
To: mark at ludlow.com, "Discussion of biomass pyrolysis and
gasification" <gasification at listserv.repp.org>
Message-ID:
<31a4f6f00710290138m76c62a59vdf725890c2ef2d6a at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
>
>
> My mind--rightly or wrongly--is stuck on the notion of an updraft
> pyrolyzer
> (equivalent to a reboiler in a distillation column) and progressive
> condensation zones and recycle loops that avoid ever having to deal with
> tars in a crystallized state; recycling them through the O2-lean pyrolysis
> zone until they finally emerge as low-boiling point alkanes along with the
> non-condensible CO and H2.
mark, there was a tar removal process presented at the gasificaiton
conference in sf which is based on this notion of careful handling of tar
dew points for tar separation from the gas stream. the process is called
OLGA. here's one link to start with.
http://www.ecn.nl/en/bkm/products-services/olga/
personally, i think there is easier traction to be had in approaches like dr
lefcort's in the envirocycle, which acknowledges tars are going to be made,
so focussing burning them while hot in a combustor/combustion zone, rather
than trying to separate them out of the mixed gas.
tar recycle systems which mine pyro smoke from the pyrolysis zone and return
it hot directly to the combustion zone through the air nozzles (or related
feed) are not difficult and sadly underexplored. there are examples in the
historic literature, but they seem it to ignored in most contemporary
building. note you can create a small vacuum to pull pyro smoke from the
top of a fuel hopper by a venturi in your air inlet plumbing. if you are
doing a top down air inlet on an imbert type, you can do this venturi mining
very simply with the existing pipe travelling through the hopper (where the
pryo smoke is gathering)
one does not need to rely on the constriction point of the combustion zone
to ensure all pyro smoke is properly directed through a hot combustion
area. better to mine it ahead of time, pre mix it with air, so that it goes
off immediately on inlet to the combustion zone via the air nozzles.
such is equally possible with many other architectures one may be scheming.
j
Likely I'm missing something terribly obvious, huh?
>
> Mark
>
> -----Original Message-----
> From: gasification-bounces at listserv.repp.org
> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of Art Krenzel
> Sent: Sunday, October 28, 2007 12:45 PM
> To: Discussion of biomass pyrolysis and gasification
> Subject: [Gasification] Two stage gasification
>
> Jim and others.
>
> The Danes have been doing high quality two stage gasification for years.
>
> Just GOOGLE two stage gasification Technical University of Denmark and
> you
> will get more information on high quality gas producing , simple to
> operate
> gasifiers than you will ever want.
>
> Let us not re-invent the wheel here or make high quality gas seem like an
> impossibility.
>
> Art Krenzel
>
>
> ----- Original Message -----
> From: "jim mason" <jimmason at whatiamupto.com>
> To: "Mark Ludlow" <mark at ludlow.com>
> Cc: <gasification at listserv.repp.org>
> Sent: Sunday, October 28, 2007 12:31 PM
> Subject: Re: [Gasification] combustion of tarry producer gas
>
>
> > On 10/27/07, Mark Ludlow <mark at ludlow.com> wrote:
> >>
> >> I agree, in priciple. But the challenge for widespread application of
> >> gasification demands that small-unit applications not be fuel
> sensitive.
> >> (Who wouldn't love to have almond shells to run?) Face it: an updraft
> >> gasifier where fuel can be dumped on a reactive bed is the simplest
> >> scenario. Sure, it takes no advantage of passing the pyrolyzed gas
> >> through a
> >> cracking zone. But I have a sneaking suspicion that combining all
> >> requirements of tar-free gasification in a single device may not be the
> >> most
> >> practical solution in all instances (my apologies to Doug Williams).
> It's
> >> certainly more elegant to have a single chamber doing gasification and
> >> cracking but who would refuse access to a fuel source composed of only
> >> charcoal even if, lb-for-lb, its HHV was less than properly-sized dry
> >> biomass? Everyone would rather avoid tar from the outset by having pure
> C
>
> >> as
> >> a fuel (in an ideal world). But is it possible to "close-couple"
> >> gasification and tar cracking without making them integral to a single
> >> process?
> >>
> >
> > i apologize if i created the impression that i think updrafts are off
> the
> > table. of course there are many applications and subprocess needs where
> > an
> > updraft is well suited. the requirements for dealing with the output
> gas
> > can be complicated if more than an immediate close coupled burn, without
> > passing through a fan.
> >
> > mark is correct that a great attraction of an updraft is its fuel
> > flexibility. as the air/gasflow is going in the opposite direction of
> > gravity, they are much less likely to cake up. higher moistures will
> only
> > degrade the energy in the product gas, but not stop the gasifier from
> > working, like in a downdraft.
> >
> > at this point i don't find any single vessel solution to be able to
> > adequately process fuels with the needed flexibility for tolerable real
> > operation, and produce a consistent tar free gas. the self regulating
> > simplicity of combustion against reduction, with radiated/conection heat
> > running pyrolysis, in a single vessel is elegant in its minimalism, but
> it
> > is famoustly difficult to control. the self-regulating character of
> these
> > single vessel solutions only work within a very narrow band of fuel and
> > air
> > humidity conditions. i find the world to not easily provide these
> > conditions. thus most gasification efforts become fuel standardization
> > efforts. and very few survive this transformation.
> >
> > most all my work towards fuel agnostic, tar free gasifiers, is moving
> > towards pulling each of the zones apart and contending with them
> > separately,
> > either in dedicated and well separated spaces in a "single vessel", or a
> > fully separate dedicated vessel. the processes can then be recombined
> and
> > controlled actively with microprocessors so that the great variation in
> > performance as fuel changes, can be compensated for in real time. i
> don't
> > have a finished system yet, but i'm going as fast as i can.
> >
> > such gasifiers cannot be built from junk quite so easily, but they also
> > hold
> > the potential to actually work in real world conditions.
> >
> > for inspiration, i keep a large dumpster bin of real world organic
> matter
> > outside my shop. it has the waste of the world in it that i think a
> > gasifier should be able to deal with: mixed construction waste with
> nails,
> > plastic cups, newspaper, cardboard boxes, dimensioned lumber, coffee,
> > brush
> > clippings, tires, water bottles, etc etc etc. i stare at this pile
> daily
> > to
> > remind myself of the range of what a gasifier needs to be able to intake
> > to
> > actually fulfill its promise of "energy from any waste biomass"
> >
> > right now we are mostly at "energy from very carefully preprocessed
> forms
> > of
> > organic waste, handled with such care and knowledge, that they are
> really
> > a
> > high grade fuel again before they go in the gasifier". and thus is why
> so
> > few current small scale gasfiier installations ever work in the
> end. the
> > limitations of fuel type and condition, as well as expertise required to
> > maintain these conditions, is not reasonable for typical users.
> >
> > we are not going to solve this problem with any minor tweak to an imbert
> > type. but i think we can solve it by the thoughtful separation and
> > control
> > of the subprocesses, with active embedded control for recombining the
> > parts
> > and flows between them. this will result in hybrid systems that have
> > combinations of various "traditional" types into a single system. and
> > yes,
> > updrafts might be quite important as subprocesses in such a system.
> >
> > j
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Rex Z. has expressed a vision of a dual-zone reactor. Few experimenters
> or
> >> small-scale devotees are likely to attempt the fluid bed model that he
> >> describes, but a critical notion is the physical division of
> gasification
> >> and 'refinement' within a continuous flow stream. In its simplest
> >> expression, optimizing a primary generator to become an efficient
> >> converter
> >> of solid feed substrate to gas is one task; and providing the
> environment
>
> >> to
> >> reduce this gas to short-chain combustible components becomes the
> second
> >> task.
> >>
> >>
> >>
> >> Gasification, in its present popular incarnation, assumes that cracking
> >> of
> >> tarry gas requires a parasitic process deriving energy from the primary
> >> reaction zone. This is very elegant, in theory, but is dependent on a
> >> number
> >> of mechanical parameters such as fuel condition and form factor. I ask:
> >> cannot the tars from a simple updraft gasifier be considered a fuel
> >> source
> >> unto themselves? Between their gaseous state and their troublesome
> >> crystallized state there must be a liquid state that would facilitate
> >> their
> >> transport back into either the primary gasification/reduction zone or a
> >> secondary oxidation zone, providing energy for the primary gasification
> >> transformation.
> >>
> >>
> >>
> >> Am I dreaming?
> >>
> >>
> >>
> >> Mark
> >>
> >>
> >>
> >> *From:* jimmmason at gmail.com [mailto:jimmmason at gmail.com] *On Behalf Of
> >> *jim
> >> mason
> >> *Sent:* Saturday, October 27, 2007 12:27 AM
> >> *To:* mark at ludlow.com; Discussion of biomass pyrolysis and gasification
> >> *Subject:* Re: [Gasification] combustion of tarry producer gas
> >>
> >>
> >>
> >>
> >>
> >> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:Tom,
> >> What do you estimate that the temperature of condensation of typical
> >> woodgas
> >> tar is?
> >> Mark
> >> --------------------------
> >>
> >> this is commonly desciribed as above 350degC
> >>
> >> but really, there is a tremendous variation between primary, secondary
> >> and
> >> tertiary tars. or light and heavy. depending how terms are defined.
> >>
> >> leland has much more experience in long running installation than i and
> >> many others here. my knowledge is only from running prototype rigs to
> >> date. so in general, i defer to leland and other like experienced
> elders
>
> >> in
> >> this endeavor.
> >>
> >> so yes, avoid updraft gasifiers with biomass at nearly all costs. make
> >> clean gas from the begininng. innumerable problems will be less
> onerous
> >> downstream if you do so.
> >>
> >> jim
> >>
> >>
> >> On 10/26/07, *Mark Ludlow* <mark at ludlow.com> wrote:
> >>
> >> Tom,
> >> What do you estimate that the temperature of condensation of typical
> >> woodgas
> >> tar is?
> >> Mark
> >>
> >> -----Original Message-----
> >> From: gasification-bounces at listserv.repp.org
> >> [mailto:gasification-bounces at listserv.repp.org] On Behalf Of
> >> LINVENT at aol.com
> >> Sent: Friday, October 26, 2007 10:35 PM
> >> To: jimmason at whatiamupto.com; gasification at listserv.repp.org
> >> Subject: Re: [Gasification] combustion of tarry producer gas
> >>
> >> Burning tarry producer gas may appear to be an easy job, but after a
> >> while
> >> there are problems with it. One is that the tars may crack around the
> hot
> >> combustion areas and carbon up the pipes, ports apertures or other
> parts
> >> exposed to
> >> the direct or indirect heat from the combustion of the gas. Tars will
> >> condense
> >> anywhere in the transport pipes. Once condensed, they will solidify
> over
> >> time
> >> and block the pipes. They also drip off the end of the combustion pipe
> >> into
> >> the combustion chamber and pile up or burn within the chamber. If any
> >> long
> >> term
> >> usage of them is expected without significant pipe cleaning downtime,
> the
> >> gas
> >> needs to be clean.
> >>
> >>
> >>
> >> Sincerely,
> >> Leland T. Taylor
> >> Leland T."Tom" Taylor
> >> President
> >> Thermogenics Inc.
> >> 7100-F 2nd St. NW Albuquerque, NM 87107
> >> Phone:505-463-8422 Fax:505-268-9206 (call first)
> >> Web: thermogenics.com
> >>
> >>
> >>
> >> **************************************
> >> See what's new at http://www.aol.com
> >> _______________________________________________
> >> Gasification mailing list
> >> Gasification at listserv.repp.org
> >>
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> >> http://gasifiers.bioenergylists.org
> >> http://info.bioenergylists.org
> >>
> >>
> >> _______________________________________________
> >> Gasification mailing list
> >> Gasification at listserv.repp.org
> >>
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> >> http://gasifiers.bioenergylists.org
> >> http://info.bioenergylists.org
> >>
> >>
> >>
> >>
> >> --
> >>
> >>
>
>
----------------------------------------------------------------------------
> ----
> >> jim mason
> >> website: www.whatiamupto.com
> >> current project: mechabolic ( http://www.mechabolic.org)
> >> announce list:
> http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
> >>
> >
> >
> >
> > --
> >
>
>
----------------------------------------------------------------------------
> ----
> > jim mason
> > website: www.whatiamupto.com
> > current project: mechabolic (http://www.mechabolic.org)
> > announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
> > _______________________________________________
> > Gasification mailing list
> > Gasification at listserv.repp.org
> > http://listserv.repp.org/mailman/listinfo