Lecture 20 Thursday 3/20/08 Multiple Reactions with Heat Effects

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Lecture 20 Thursday 3/20/08Multiple Reactions
with Heat Effects

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User Friendly Equations Relate T and X or Fi
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Heat Exchange
Elementary gas phase reaction carried out in a
PBR The feed consists of both inerts I and
Species A with the ratio of inerts to the species
A being 2 to 1.

• (a) Adiabatic. Plot X, Xe, T and the rate of
  disappearance as a function of V up to V  40
  dm3.
• (b) Constant Ta. Plot X, Xe, T, Ta and Rate of
  disappearance of A when there is a heat loss to
  the coolant and the coolant temperature is
  constant at 300 K for V 40 dm3. How do these
  curves differ from the adiabatic case?
• Variable Ta Co-Current. Plot X, Xe, T, Ta and
  Rate of disappearance of A when there is a heat
  loss to the coolant and the coolant temperature
  varies along the length of the reactor for V 40
  dm3. The coolant enters at 300 K. How do these
  curves differ from those in the adiabatic case
  and part (a) and (b)?
• (d) Variable Ta Counter Current. Plot X, Xe, T,
  Ta and Rate of disappearance of A when there is a
  heat loss to the coolant and the coolant
  temperature varies along the length of the
  reactor for V 20 dm3. The coolant enters at 300
  K. How do these curves differ from those in the
  adiabatic case and part (a) and (b)?

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Mole Balance (1)
Rate Law (2) (3) (4)
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Stoichiometry (5)
(6) Parameters (7) (15)
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Energy Balance
Adiabatic and ?CP 0 (16A) Additional
Parameters (17A)  (17B) Heat
Exchange (16B)
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(16B)
A. Constant Ta (17B) Ta 300 Additional
Parameters (18B (20B) Ta, , Ua, B.
Variable Ta Co-Current (17C) C. Variable Ta
Counter Current (18C) Guess Ta at V 0 to
match Ta Tao at exit, i.e., V Vf
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User Friendly Equations Relate T and X or Fi
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Heat Exchange
Elementary liquid phase reaction carried out in a
PFR The feed consists of both inerts I and
Species A with the ratio of inerts to the species
A being 2 to 1.
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Multiple reactions with heat effects
Multiple Rxns Mole balances every species (no
conversion!) Rates rate laws net/relative
rates Stoichiometry Heat effects
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Rate is given for 2C, but ?HR is given for 2A!
Make sure it is in respect to A A needs a
coefficient of 1!!!!!!!
1) Mole balance
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2) Rate laws 3) Stoich 4) Heat
effects Parameters