Re: GAS-L: maximum pressure

[JackProot@aol.com]

In a message dated 02-01-28 03:06:06 EST, vanderdrift@ecn.nl writes:

<< Can anyone give me arguments why biomass gasification is or is not possible
 at 50 bar? I know that the composition changes, tar concentration increases
 and the inert gas consumption is high, but are there any fundamental
 barriers? >>

When the pressure increases, the reactions are displaced towards a smaller
final volume. For instance  CO + 1/2O2 = CO2   will shift to the right.
As O2 is introduced with the purpose of making CO, the generator soon
runs short of oxygen and elemental carbon is the main by-product.
(In my simple thermodynamic model at least, maybe tar in a real
world kettle !) 
Gasification will be very poor under high pressure, the gas produced
containing a lot of CO2 and H2O, and very little CO and H2.
This effect increases with the pressure and decreases when the 
temperature rises. (It appears at 5 bar and 750°C or 500 bar and 1200°)
But why make your life more complicated ? I fail to see the interest of
working under pressure.

Best regards.

Jacques

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