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Table Data sheet of distillation unit under study.
Sr. No. Process Specification
1 Feed Rate =4000 kg/h at bubble point
2 Feed Composition (mass %)
Methanol 1.65
Acetaldehyde 2.21
Methyl formate 3.77
Ethanol 1.06
Acetone 13.11
Methyl acetate 2.34
Methyl ethyl ketone 0.57
Ethyl acetate 0.25
Diethyl ketone 0.1
Water 72.68
Acetic acid 1.75
Formic acid 0.37
Propionic acid 0.14
3 Separation Targets (mass %)
Distillate: water < 10%
Bottoms: acetone < 0.22%, methanol < 2%, acidity< 3% (Acidity is the sum of the mass fraction of the acids i.e. acetic acid, formic acid and propionic acid in the bottoms.)
4 No. of trays =35
5 Column diameter = 0.738 m
6 Feed tray= 16
7 Steam tray = 35
7 Steam conditions
Temperature =141°C
Pressure = 375 kPa
8 Column head pressure = 100 kPa
9 Design Temperature= 115°C
10 Design Pressure= 190 kPa
Process Description
The unit under discussion is part of a hydro carbon recovery plant, which removes hydrocarbons
and other solvents from the off-gases. Water, ace-tone, methanol, and acetic acid are the main components of the feed stream. The product stream (ace-tone rich) is separated from the effluent by using
live steam injection. The column has a diameter of
0.728m
and
consists of 35 trays. The live steam
is entered at stage 35 at temperature 141°C and
375 kPa pressures.
The feed, which is at its bubble point, is entered
at stage 16 (the stages are numbered from top to bot-tom) with a column head pressure of 100 kPa. The
separation targets (mass %) are distillate: water <10%; bottoms: acetone < 2000 ppm; methanol < 2%;acidity < 3%, where acidity is the sum of the mass
fraction of the acids, that is, acetic acid, formic acid,
and propionic acid in the bottoms stream.
The feed rate is about 4000 kg/h. The temperature
at stage 24 is controlled via modification of the steam
rate. The design temperature of the column is 115°C
and design pressure is 190 kPa.
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