Problem SM.2 Questions
your_name
date
1. Based on physical properties such as critical temperature, critical pressure, and normal boiling
temperature for each reaction component, why should the effluent leaving the reactor be only in
the vapor or gas phase? To verify the stream phase, it may help to think of a phase (PT) diagram
for each pure component. Physical properties of various chemical components are given in Ch. 1.
Compound
TNBP, °C
TC, °C
PC, kPa
-252.60
64.65
100.00
110.65
136.20
145.16
-230.86
239.45
374.15
318.65
343.95
362.85
1925.55
7376.45
22,120.00
4100.04
3607.12
3840.00
Hydrogen
Methanol
Water
Toluene
Styrene Monomer
Ethylbenzene
Reactor
Inlet, °C
Reactor
Outlet, °C
Reactor
Inlet, kPa
Reactor
Outlet, kPa
The reactor effluent temperature of ________°C is ___________ the critical temperature for some or
all of the chemical components. Since each of these chemical components in the effluent stream
would exist in the ________ phase as a pure compound, the mixture of these chemical compounds in
the reactor effluent exists in the ________ phase too.
The reactor effluent temperature of ________°C is below the critical temperature for some or none of
the compounds. If none, then the above paragraph only applies; otherwise, complete the next
paragraph.
The boiling temperatures for pure water, pure styrene monomer, and pure ethylbenzene are 137, 197,
186°C, respectively, at 330 kPa. These values were determined using HYSYS. Since the reactor
effluent temperature is _______________ than the boiling temperatures of these chemical compounds
at 330 kPa, these compounds would exist in the _________ phase.
2. At what temperature in °C do two phases (vapor-liquid) start to occur on cooling? Do three
phases (vapor-liquid-liquid) start to occur on cooling?
In the HYSYS program, the Performance Table for Process Unit E1 provides the answers to
this question for a reactor inlet temperature of _______°C. The number of data points to be
used in the full table is 500. Two-phases (vapor-liquid) occur at the dew point of _______°C
for a Vf = 1, while three phases (vapor-liquid-liquid) occur at around _______°C for when a
heavy-liquid mass flow starts to occur.
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your_name
Problem SM.2 Questions
date
3. On a molar basis, what fraction of Stream S12 after cooling to 38°C goes to the vapor phase of
the decanter? To the organic phase? To the aqueous phase?
Reactor Inlet Temperature of _______°C
Fraction of S12 in vapor phase =
Fraction of S12 in organic phase =
Fraction of S12 in aqueous phase =
nS 13
nS 12
nS 14
nS 12
nS 15
nS 12

__________ kgmol / h

__________ kgmol / h

__________ kgmol / h
__________ kgmol / h
__________ kgmol / h
__________ kgmol / h
 ____________
 ____________
 ____________
4. On a mass basis, what fraction of Stream S12 after cooling to 38°C goes to the vapor phase of
the decanter? To the organic phase? To the aqueous phase?
Reactor Inlet Temperature of _______°C
Fraction of S12 in vapor phase =
mS 13 _____________ kg / h

 ____________
mS 12 _____________ kg / h
Fraction of S12 in organic phase =
mS 14 _____________ kg / h

 ____________
mS 12 _____________ kg / h
Fraction of S12 in aqueous phase =
mS 15 _____________ kg / h

 ____________
mS 12 _____________ kg / h
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