The following endothermic reaction is to be carried out in an interstage reactor system in which inerts are injected between the reactors to increase the temperature.
An inert I is injected at the points shown below:
Sketch the conversion-temperature trajectory for the above reaction system.
Hint 2: Sketch X vs. T using the energy balance equation
Hint 3: Complete an energy balance around injector point to calculate T2
and Keq=0.1 and T2
The adiabatic energy balance is
From the energy balance we know the temperature decreases with increasing conversion.
(The endothermic heat of reaction is positive.)
Only A enters:
or
where (DHRX/CPA) is the slope in each case.
Energy Balance around junction:
Solving for T2
If CPA = CPB,
Because we are only adding inerts, we can still treat X as the overall conversion up to any point.
An inert I is injected at the points shown below:
Sketch the conversion-temperature trajectory for an endothermic reaction.
Solution
For an endothermic reaction, the equilibrium conversion increases with increasing T. Forand Keq=0.1 and T2
The adiabatic energy balance is
From the energy balance we know the temperature decreases with increasing conversion.
(The endothermic heat of reaction is positive.)
Only A enters:
or
where (DHRX/CPA) is the slope in each case.
Energy Balance around junction:
Solving for T2
If CPA = CPB,
Because we are only adding inerts, we can still treat X as the overall conversion up to any point.