Page 58 - Process simulation and control using Aspen

INTRODUCTION AND STEPWISK ASPEN PLUS SIMULATION 51

1 .4 Find the bubble point and dew point temperatures of a mixture of 0.4 mole fraction
toluene and 0.6 mole fraction rso-butanol at 101.3 kPa. Assume ideal mixture
and inlet temperature of 50oC, pressure of 1.5 atm, and flow rate of 100 kmol/hr.
1 .5 Find the bubble point and dew point temperatures and corresponding vapour
and liquid compositions for a mixture of 33 mole% n-hexane, 33 mole% n-heptane
and 34 mole% n-octane at 1 atm pressure. The feed mixture with a flow rate of
100 kmol/hr enters at 50oC and 1 atm. Consider ideality in both liquid and vapour
phases.
1 .6 Compute the bubble point and dew point temperatures of a solution of
hydrocarbons with the following composition at 345 kN/m2(see Table 1.4).

TABLE 1.4
Component Mole fraction
c3 0 .05
n-C 4 0 . 25
n-C 5 0 .4
Ce 0 . 3
The ideal solution with a flow rate of 100 kmol/hr enters at 50oC and 1 atm.
1 .7 Calculate the bubble point pressure at 40oC of the following hydrocarbon stream
(see Table 1.5).
TABLE 1.6
Component Mole fraction
c, 0 . 05
c2 0 . 1
Ca 0 . 15
i-C 4 0 . 1
n-C 0 . 2
4
i-C 0 . 15
s
n-C 5 0 . 15
c6 0 . 1
Use the SRK thermodynamic model and consider the inlet temperature of 30oC,
pressure of 4.5 bar and flow rate of 100 kmol/hr.
1 .8 A binary mixture, consisting of 50 mole% ethanol and 50 mole% 1-propanol, is
fed to a flash drum (Flash2) with a flow rate of 120 kmol/hr at 3.5 bar and 30oC.

(a) Produce T-xy plot at a constant pressure (1.013 bar)
(b) Produce P-xy plot at a constant temperature (750C)
(c) Produce xy plot based on the data obtained in part (b)
Consider the RK-Soave thermodynamic model as a base property method.
1 .9 A ternary mixture with the following component-wise flow rates is introduced
into a decanter model run at 341.1 K and 308.9 kPa. To identify the second
liquid phase, select n-pentane as a key component (see Table 1.6).