[Gasification] Fluidised Bed Reactor
Kevin C
kchisholm at ca.inter.net
Thu Nov 28 08:54:25 CST 2013
Dear Dan
Quoting Carefreeland at aol.com:
> Doug and all,
> Would some sort of a high temp molecular cracker be a good companion
> to create a quality gas from a fluidised bed? Possibly some steam and / or
> preheated air.involved? Seems if you wrapped the exhaust back through the
> hottest part of the flame in a reactor tube this can be accomplished.
> Sorry but I have been kinda outta the loop for a while.
# Start by appreciating the two Fundamental Rules of Thermodynamics
and Thermo Chemistry:
Fundamental Rule #1: You can't get something for nothing
Fundamental Rule #2: As a matter of fact, you can't even break even.
For example, the reaction
C + O2 --> CO2 (`1)
is strongly exothermic, and gives off about 14,000 BTU per pound of
carbon that is oxidized.
If there was insufficient O2, and the C was only burned to CO, as follows:
C + 1/2O2 --> CO (2)
then only abut 4,000 BTU would be released per pound of carbon.
If we wanted to reverse reaction #1, we would have to put back 14,000 BTU/Lb C
OR, in the case of a gasifier, where the reaction
CO2 + C --> 2 CO (3)
is desired, we would have to "put back" energy as follows:
14,000 + 0 --> 2x4,000 + "X"
14,000 --> 8,000 + "X"
and it is obvious that "X" is 6,000 BTU, in order to respect
Fundamental Rule #1
"Molecular Crackers" and "Catalysts" do indeed work, but only when the
fundamental need to add or remove energy from a reaction is respected.
As long as the "fundamental need for an energy balance" is respected,
then many things are possible.
Best wishes,
Kevin
>
> Dan Dimiduk
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