[Gasification] fluidized bed temps?

[Tom Miles]

Jim,

There is actually quite a lot literature on fluid bed gasification that
matches quite well with experience. You can run a bed in the 1200-1400F
range with most fuels. You can control temperature quite well. This is a big
benefit of fixed and circulating fluid bed gasifiers and combustors. You can
have low peak temperatures throughout the reactor. 

Read Mike Lewis' paper on staged gasification
http://gasifiers.bioenergylists.org/lewisstagegas

Also read Energy Product of Idaho literature on FB gasification.
http://www.energyproducts.com/EPITechnology.htm

Other suppliers may have similar descriptive process data.

And of course we discussed the CRC book last month I can see that we will
have to put up a bibliography on gasification.   

Tom Miles

-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of jim mason
Sent: Friday, August 03, 2007 2:03 PM
To: Discussion of biomass pyrolysis and gasification
Subject: [Gasification] fluidized bed temps?

i'm running a fluidized bed type gasifier and am curious about how my
measured temps compare with the experience of others.

i have a type K thermocouple on a long rod that i can move up and down
in the tube.  in the "combustion" area i'm only getting temps in the
1100-1200C range tops.  often down to 900C.  as i pull the rod up, it
quickly drops to 800-600C and stays there for quite a ways up the
tube.  the drop gradiant is very fast after the combustion zone.

my set up is far from rigorous at this point, but i'm surprised how
low these readings are.  when i put the same thermocouple in a
stratified downdraft combustion zone, i read at least 1300C, and often
it goes off the scale at 1400C (the top for type K thermocouples).

do fluidized beds typically run cooler as i'm seeing?  it makes sense
that they would, given the non concentrated nature of the combustion,
but i have not seen an expected temp profile for a fluidized bed.

can anyone point me to and/or send a chart with typical temp profiles
for fluidized beds?

thanks in advance, as usual.

jim



-- 
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jim mason
website: www.whatiamupto.com
email: jimmason at whatiamupto.com
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current project: mechabolic (http://whatiamupto.com/mechabolic/index.html)

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