[Gasification] A small literature review re: syngas

Wed Jan 26 07:53:19 CST 2011

Dear Dr. Kutney,
I am an absolute novice in this field. The work that I have so far conducted
dealt with biogas, which is produced in an anaerobic biological process.
Since ligno-cellulosic material cannot be digeseted by the anaerobic
process, and because I knew that pyrolysis produced gas, I pyrolysed
ligno-cellulosic material under anaerobic conditions, collected the gas over
water, and found that it burned. The tarry fraction in the gas was condensed
out of it when it passed through water. I wanted to know the composition of
the gas that I had produced, and asked some knowledgeable persons in my
city. Their answer did not satisfy me, because the so called knowledgeable
persons told me that the gas contained 55% nitrogen. Because I had doubts
about the presence of nitrogen, I posed the question to this group. I thank
members of this group because some of them gave me a satisfactory answer.  I
am not worried about the definition.
Yours
A.D.Karve

On Wed, Jan 26, 2011 at 1:59 AM, Gerald Kutney <gkutney at shaw.ca> wrote:

> I have followed the discussion on the definition of syngas (synthesis gas)
> with great interest.  Although there are adamant views that syngas should be
> narrowly defined, I have yet to see early references that back up this
> claim.  The term "synthesis gas" appears to have gained popularity during
> the '40's (possibly before) to describe the raw material for the FT process;
> however, it quickly became the popular term for manufactured gas.  In the
> second edition of the iconic Kirk-Othmer, Encyclopedia of Chemical
> Technology, one is directed to the chapter on manufactured gas when looking
> for synthesis gas (see vol. 10, p. 355, 1966), where it is mentioned to
> produce synthetic chemicals from the water gas and water gas shift
> reactions.  In Riegel's, Industrial Chemistry, 1962, a list of synthesis gas
> methods are listed that mimic manufactured gas and includes gasification
> with air.  And on p. 892, synthesis gas is simply defined as the mixture of
> CO and H2.
>
> I respect the opinion of the members of this list, but could you supply
> early references to back up your definitions.  I believe that this is an
> important issue to be cleared up, as there is definite confusion on whether
> syngas should have a limited definition or a broad definition.
>
>
> Gerald Kutney, Ph.D.
> Managing Director
> Sixth Element Sustainable Management
> www.6esm.com
>
>
> -----Original Message-----
> From: gasification-bounces at lists.bioenergylists.org [mailto:
> gasification-bounces at lists.bioenergylists.org] On Behalf Of jim mason
> Sent: Wednesday, December 29, 2010 2:40 PM
> To: gasification at bioenergylists.org
> Subject: Re: [Gasification] A small literature review re: syngas
>
> On Wed, Dec 29, 2010 at 1:13 PM, Bear Kaufmann <bear at allpowerlabs.org>
> wrote:
> > I looked through some of the papers I have on hand, and extracted the
> > interesting parts as they relate to the latest discussion, FWIW:
> >
> > In short, the usage from the above doesn't appear entirely clear.
> > But in general, syngas is often suggested to have been upgraded, or of a
> > higher CO/H2/energy content. Syngas is often used to refer to gas
> intended
> > to be used for synthesis of products. Syngas does also seem to be used as
> > general term in some cases.
> >
>
>
> bear, in reading through your 6 examples here, i find 4 of them use
> the term "syngas" in some flavor of a general term for the gas
> produced through some form of biomass thermal conversion.  its
> relationship to synthesis processes and no/low nitrogen gas is also
> there of course.  but the prevalence of the "generic" usage is
> surprising.  i'm surprised to see even some major names in
> pyrolysis/biochar are using it to name the gas from pyrolysis.
>
> given this over majority leaning towards the generic use, why do you
> summarize the state of affairs by affirming the more "traditional"
> senses of the term?  it seems the numbers are leaning in the other
> direction.  of course your sample is anecdotal, so putting numbers to
> the resulting statistics is suspect.  but still, the emphasis in your
> conclusion i do not see in the sample.  btw, how did you generate this
> sample?
>
> when we started this disucssion, my guess was that the generic usage
> of the term was maybe a 10-20% phenomenon.  examples are piling up
> that it is actually much higher than this.  it seems even higher in
> the academic world than in our local online circle.
>
> j
>
>
>
>
>
>
> >
> > "Fuel gas can be used directly as fuel in gas burners or internal
> combustion
> > engines and gas turbines. Fuel gas, after purification and possibly water
> > gas shift to adjust the H2/CO ratio, can be described as a syngas (a
> mixture
> > of H2 and CO), which can be used to manufacture methanol, ammonia,
> Fischer
> > Tropsch liquids, or hydrogen for use in fuel cells (4). The suitability
> for
> > a particular usage, i.e. the fuel gas quality, is determined by the gas
> > composition and the level of contamination by particulates, alkali
> > compounds, nitrogen-containing components, sulphur and tars (5)."
> > from Kalisz, S. et al. Energy Balance of High Temperature Air/Steam
> > Gasification of Biomass in Up-Draft, Fixed-Bed Type Gasifier. Int. Conf.
> on
> > Incineration and Thermal Treatment Technologies, Phoenix, Arizona
> (2004).at
> > <http://gasunie.eldoc.ub.rug.nl/FILES/root/2004/3265200/3265200.pdf>
> >
> > "Fast pyrolyzers rapidly (∼1 s) heat dry biomass (10% H2O) to ∼500°C and
> > thereby thermally transform biomass into bio-oil (∼60% of mass), syngas
> > (∼20% of mass), and charcoal (∼20% of mass). The energy required to
> operate
> > a fast pyrolyzer is ∼15% of the total energy that can be derived from the
> > dry biomass. Modern systems are designed to use the syngas generated by
> the
> > pyro- lyzer to provide all the energy needs of the pyrolyzer."
> > from Laird, D.A. The Charcoal Vision: A Win Win Win Scenario for
> > Simultaneously Producing Bioenergy, Permanently Sequestering Carbon,
> while
> > Improving Soil and Water Quality. Agron J 100, 178-181(2008).
> >
> > "To improve the thermal efficiency and predict the composition of syngas,
> > several numeric models have been developed for biomass conversion
> systems."
> > from Rogel, A. & Aguillón, J. The 2D Eulerian Approach of Entrained Flow
> and
> > Temperature in a Biomass Stratified Downdraft Gasifier. American Journal
> of
> > Applied Sciences 3, 2068-2075(2006).
> > Comments: Shows a stratified downdraft model with inputs of air and
> biomass,
> > outputs of syngas and ashes
> >
> > "The term ‘pyrolysis’ is typically used either for ...[analytical
> > purposes]... or for bioenergy systems that capture the off-gases emitted
> > during charring and used to produce hydrogen, syngas, bio-oils, heat or
> > electricity (Bridgwater et al, 1999)."
> > from Lehmann, J. & Joseph, S. Biochar for environmental management:
> science
> > and technology. (Earthscan/James & James: 2009).
> >
> > "High purity syngas (i.e. low quantities of inerts such as N2) is
> extremely
> > beneficial for fuels and chemicals synthesis since it substantially
> reduces
> > the size and cost of downstream equipment. However, the guidelines
> provided
> > in Table 5 should not be interpreted as stringent requirements. "
> > "There is more latitude with regard to syngas composition for engine
> > combustion than for turbine combustion."
> > "To be considered interchangeable with conventional fossil fuels (natural
> > gas or distillate oils) and to ensure maximum flexibility for industrial
> or
> > utility applications, syngas heating value needs to be above 11 MJ/m3"
> > "At temperatures greater than 1200-1300oC, little or no methane, higher
> > hydrocarbons or tar is formed, and H2 and CO production is maximized
> without
> > requiring a further conversion step."
> > "Biomass gasification is the conversion of an organic...carbonaceous
> > feedstock by partial oxidation into a gaseous product, synthesis gas or
> > “syngas,” consisting primarily of [H2 and CO] with lesser amounts of
> [CO2,
> > CH4], higher hydrocarbons (C2+), and nitrogen (N2). The reactions are
> > carried out at elevated temperatures, 500-1400oC, and atmospheric or
> > elevated pressures up to 33 bar (480 psia). The oxidant used can be air,
> > pure oxygen, steam or a mixture of these gases. Air-based gasifiers
> > typically produce a product gas containing a relatively high
> concentration
> > of nitrogen with a low heating value between 4 and 6 MJ/m3 (107-161
> > Btu/ft3). Oxygen and steam-based gasifiers produce a product gas
> containing
> > a relatively high concentration of hydrogen and CO with a heating value
> > between 10 and 20 MJ/m3 (268-537 Btu/ft3)."
> > "Table 8. Compositions of Biomass-Derived Syngas" - includes N2 from
> 0-56%,
> > H2 from 5-43.3%, CO from 9-67%, CO2 from 4-40%
> > ...
> > from Ciferno, J.P. & Marano, J.J. Benchmarking biomass gasification
> > technologies for fuels, chemicals and hydrogen production. US Dep of
> Energy
> > NETL (2002).at
> > <
> http://seca.doe.gov/technologies/coalpower/gasification/pubs/pdf/BMassGasFinal.pdf
> >
> >
> > "The resulting fuel is a producer gas (a synthesis gas or syngas) that
> > consists primarily of varying ratios of hydrogen and carbon monoxide
> (CO)."
> > from Mukhtar, S. Manure to Energy: Understanding Processes, Principles
> and
> > Jargon. (2006).at
> > <
> http://repository.tamu.edu/bitstream/handle/1969.1/87462/pdf_2425.pdf?sequence=1
> >
> >
> > In short, the usage from the above doesn't appear entirely clear.
> > But in general, syngas is often suggested to have been upgraded, or of a
> > higher CO/H2/energy content. Syngas is often used to refer to gas
> intended
> > to be used for synthesis of products. Syngas does also seem to be used as
> > general term in some cases.
> >
> > My preferred usage has been to call the gas the air-blown GEK makes
> > "producer gas". Wood gas notes that the carbon source was biomass, though
> I
> > don't prefer the term. "Syngas" being made with O2 or steam.
> > The problem with the above is it doesn't leave a general catch-all term.
> >
> > Cheers,
> > Bear Kaufmann
> > All Power Labs
> >
> > _______________________________________________
> > The Gasification list has moved to
> > gasification at bioenerglists.org - please update your email contacts to
> > reflect the change.
> > Please visit http://info.bioenergylists.org for more news on the list
> move.
> > Thank you,
> > Gasification Administrator
>
>
>
> --
>
> ------------------------------------------------------------------------------
> Jim Mason
> Website: http://www.whatiamupto.com
> Current Projects:
>   - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com
>   - Escape from Berkeley alt fuels vehicle race:
> www.escapefromberkeley.com
>   - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs
>   - Shipyard Announce list:
> http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com
>
> _______________________________________________
> Gasification mailing list
>
> to Send a Message to the list, use the email address
> Gasification at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
>
> for more Gasifiers,  News and Information see our web site:
> http://gasifiers.bioenergylists.org/
>
>
> _______________________________________________
> Gasification mailing list
>
> to Send a Message to the list, use the email address
> Gasification at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
>
> for more Gasifiers,  News and Information see our web site:
> http://gasifiers.bioenergylists.org/
>

-- 
***
Dr. A.D. Karve
President, Appropriate Rural Technology Institute (ARTI)

*Please change my email address in your records to: adkarve at gmail.com *
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/gasification_lists.bioenergylists.org/attachments/20110126/cb5fcce6/attachment.html>