Microsoft Word 321hw6_06'doc

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CHE 321 HOMEWORK SHEET 6
Question One A depropanizer is used to make
separation of paraffins. Using the conditions
below, make a process flow diagram that will
achieve the separation. Feed1 C1, C2, C3, C4,
C5, C6 (0.7, 0.12, 0.10, 0.04, 0.03,0.01)
Conditions T 225 F, P250 psia, F
1000lbmoles/hr. Thermo Package SRK Unit
Operation Distillation column Condenser
Partial, P248 psia, RR5.0, vapor rate711, _P0
Reboiler P 252psia, _P0, Butane bottom
recovery36.5 Calculate the degree of recovery
achieved for the propane from your simulation.
Question two As discussed in section 3.3 of
your text book, the following stream at 100oF
and 484 psia is to be separated by two
distillation columns into the products shown on
the table below.
The two distillation columns are as shown in Fig.
3.22 of your text book. The first column is used
to remove H2 and CH4 . The second column will
have toluene and diphenyl in the bottom
product. Using the Chemcad Simulation Software
with shortcut distillation column, SRK option
and Rmin of 1.3. 1. Find the number of stages
and the feed stages for the two columns. 2.
Calculate the recovery of methane and its purity.
3. Calculate the recovery of benzene and its
purity? 4. As an engineer, will you recommend
a sequence that separates toluene and diphenyl
first? State your reasons.