[Gasification] Emissions fines
linvent at aol.com
linvent at aol.com
Thu Feb 24 14:21:56 CST 2011
Dear Tom,
The original statement which started this thread was that
gasifiers got violations, now as I initially asked, the installations
were not gasifiers. If the industry is going to keep it's black eyes to
a minimum, it needs to deal with misnomers and the like.
Adding oxidizer over the bed also occurs in combustors. It reduces
the gas heating value by combusting some of the fixed gases which react
more rapidly than the aerosols or tars, and the reduced heating value
of the gas causes problems in operating engines as the PRM system did
in Sorrento, Italy on olive pits. There are better ways of dealing with
the tars which increase the heating value of the gas while cleaning it
adequately to operate IC engine, be transported distances and the like.
The three vessel unit which takes virtually any combustible
feedstock and converts it into a clean, cool gas suitable for engine
operation demonstrates this. A char residue from a cellulosic chemical
plant with 33% ash, 5500 btu/lb. at 20% moisture was run at what
appears to be around 40% moisture and the gas had 24-27% hydrogen in
it. The nitrogen also appears to be much less than normal air fired
gasification content. Adjustment of operating temperature changes the
hydrogen content.
Sincerely,
Leland T. "Tom" Taylor
President
Thermogenics Inc.
-----Original Message-----
From: Tom Miles <tmiles at trmiles.com>
To: 'Discussion of biomass pyrolysis and gasification'
<gasification at lists.bioenergylists.org>
Sent: Mon, Feb 21, 2011 7:34 pm
Subject: Re: [Gasification] Emissions fines
Tom,
Don't get Kevin started on definitions of gasification. :-)
Try http://en.wikipedia.org/wiki/Gasification
The plants that received fines do not have gasifiers. The only
similarity is that they convert wet wood to steam. They use fluidized
bed combustors. They use excess air directly in the fluidized bed of
sand. They also burn fuels such as urban wood waste that require acid
gas control. An FB combustor allows you to control acid gas directly by
adding limestone to the bed to form calcium sulfate or calcium chloride
that is removed as a particulate. In a combustor the heat transfer -
boiler and convective sections - are integral to the furnace-boiler
design. In the Nexterra and other gasifier application the gas is
transported from the gasifier to a burner that is in a separate boiler
enclosure. (From 1985-1998 Interpretations of the tax code allowed the
grate portion of a furnace to be called a gasifier when operated with
limited air such that staged combustion within a boiler qualified for a
producer gas tax credit. That credit has now expired.)
It's important to look at the whole system. Nexterra uses a unique
proprietary bed design, a low velocity above the bed that reduces
particulate, a partial oxidation step to clean up tars between the
gasifier and the burner in the boiler. Tar reduction is similar in
concept to what other fixed bed suppliers, like PRM and PrimEnergy,
have done for years. Combustible gas is transported from the gasifier
to a burner in the boiler. The gas fired in the boiler is clean enough
to use the ESP for particulate control. The combination of the low NOx
precursors from the gasifier and their burner design allows them good
CO and NOx control. Comparative data are in the Levelton report.
Tom Miles
-----Original Message-----
From: gasification-bounces at lists.bioenergylists.org
[mailto:gasification-bounces at lists.bioenergylists.org] On Behalf Of
linvent at aol.com
Sent: Monday, February 21, 2011 4:05 PM
To: gasification at lists.bioenergylists.org
Subject: Re: [Gasification] Emissions fines
Dear Tom,
In comparing the Kruger Products installation to the ones which
received fines, one might be tempted to say that a fixed bed is better
than a fluidized bed, but one would have to compare emission standards
between the two jurisdictions to firmly make this claim. The Nexterra
design has a relatively high tar yield.
The word gasification in my opinion is still misapplied unless
the
gas can be cleaned and transported across a jurisdictional boundary for
use, otherwise, it is still a dual stage combustor.
Sincerely,
Leland T. "Tom" Taylor
President
Thermogenics Inc.
www.thermogenics.com
505-463-8422
-----Original Message-----
From: Tom Miles <tmiles at trmiles.com>
To: 'Discussion of biomass pyrolysis and gasification'
<gasification at lists.bioenergylists.org>
Sent: Sun, Feb 20, 2011 8:24 pm
Subject: Re: [Gasification] Emissions fines
Pulp and Paper Canada (Feb 2011) reporting on a gasifier-boiler
application:
http://www.pulpandpapercanada.com/issues/story.aspx?aid=1000402062
Kruger's Biomass Gasifier Fuels Customers' Need for GreenBiomass
gasification has quantifiable environmental benefits to show customers:
fewer GHG emissions, less fossil fuel, better air quality.By: By Tony
Kryzanowski
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