Problem HY.5 Questions
team_name
date
0. What is the reactor duty in kJ/h for this isothermal process? Is the chemical reaction
endothermic or exothermic? Must heat be added to or removed from the reactor?
The reactor duty is __________ kJ/h. Since it is ________ in value, the chemical
reaction is ___________, and thus heat must be ______________ the reactor.
1. For the adiabatic reactor in the HYSYS session, only a vapor product stream was needed since
the flow rate of the liquid was zero. For the isothermal case, both a vapor and a liquid product
stream are required. Why?
The exiting material at 25°C and 1 atm has two phases—vapor and liquid—since
its ____________ is below the _____ point of __________°C.
Above what reactor exit temperature will only a vapor product stream be required?
Only a single phase of _______ for the product stream will exist above ________°C.
2. What is the acrylonitrile composition in the liquid product stream in mole fraction? In mass
fraction? In parts per million (ppm)? In kg/m3? In kgmol/m3? In molarity (M)?
xL , AN  ____________
______ of acrylonitrile per ______ of Stream L
wL , AN  ____________
____ of acrylonitrile per ____ of Stream L
ppm  _____________
(____ of acrylonitrile per ____ of Stream L)×106
____ __________ kg / h
Cˆ L , AN 

VL , AN
_________ m3 / h
 _________ kg / m
______ of acrylonitrile per ______ of Stream L
3
____ __________ kgmol / h
Cˆ L , AN 

VL , AN
_________ m3 / h
 _________ kgmol / m
M

________
kgmol ___ gmol
m
3
______ of acrylonitrile per ______ of Stream L
3
1 kgmol

1 m3
___ L
Molarity, ____ of acrylonitrile per L of Stream L
 ________ M
Each property value was obtained by copying it from HYSYS and pasting it here.
3. What assumptions were used to solve the isothermal reactor simulation problem?




continuous process
_________________________
_________________________
_________________________
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Problem HY.5 Questions
team_name
date
Compare these assumptions to those of the chemical reactor module in Appendix H of this
instructional manual. Are the assumptions the same? If not, how do they differ?
Compared to the reactor module in Appendix H, all but ____ of the assumptions
are the _____. In Appendix H, the reactor is assumed to be an ________ process.
4. Write the total mole balance equation for the isothermal reactor problem. What are the value
and units for the extent of reaction?
 ____________ 
1
kgmol
 _______  _______  _______  _______ 
_______
h
R 
 _______
kgmol
h
1
kg  rxn
nF  _________________  0
or
R 
 nV
Each total molar flow value was obtained by copying it from HYSYS and pasting it here.
What does the extent-of-reaction or R term in the total mole balance signify?
Since __ molecules of products are formed for every __ molecules of reactants
that react, a net of _____________ molecule is _________ per chemical reaction.
5. What is the energy relative imbalance (%RIB)? Show your calculations. The energy %RIB
equals 100*(energy flow in – energy flow out) / (energy flow in).
% RIBEB 
___  ___  ___  ___  ___
EF  E A
100
  _______    _______    _______    _______    _______   kJ/h 
 100

_______

_______
kJ/h










% RIBEB  _______
% RIBEB   
Each energy flow value was obtained by copying it from HYSYS and pasting it here.
In the HYSYS software, the Mass/Energy Balance page within the Flowsheet/Flowsheet Summary
menu provides the relative imbalances for material and energy.
6. What is the material relative imbalance (%RIB) on a total molar basis? Show your calculations.
The total molar %RIB equals 100*(total molar flow in – total molar flow out) / (total molar
flow in).
Page 2 of 3
Problem HY.5 Questions
team_name
___  ___  ___  ___
% RIBMB 
nF  nA
date
 100
  _______ +_______  _______  _______  kgmol/h 
  100
 _______ +_______  kgmol/h


 _______
% RIBMB  
% RIBMB
Each total molar flow value was obtained by copying it from HYSYS and pasting it here.
7. What is the material relative imbalance (%RIB) on a total mass basis? Show your calculations.
The material %RIB equals 100*(mass flow in – mass flow out) / (mass flow in).
% RIBMB 
___  ___  ___  ___
mF  mA
 100
  ________ +________  ________  ________  kg/h 
  100
 ________ +________  kg/h


 ________  ______
% RIBMB  
% RIBMB
Each total mass flow value was obtained by copying it from HYSYS and pasting it here.
How does this value compare with the %RIB on a molar basis? Explain.
The relative imbalance based on total moles is ______%, while the relative
imbalance based on total mass is _____%.
Since total mass is ________ during chemical reactions, the relative imbalance
based on total mass is the _____________ of the material relative imbalance.
In general, total moles during chemical reactions are ____________, as indicated
by the ______% and the fact that a net ______ of _____ molecule occurs per
reaction event.
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