Distillation Section
A) Wash to RS Mode: -
Following columns will be under operation
i. Analyser Column (Vacuum)
ii. Degasifying Column (Vacuum)
iii. Rectifier cum Exhaust Column (Pressure)
iv. Recovery Column (Atmospheric)
Pre-heated fermented wash will be fed to Degasifying column. Fermented
wash is stripped off alcohol by ascending vapours in Analyser column.
Rectifier vapours provide energy to Analyser column through a
Thermosiphon reboiler. Vapours of Degasifying column are condensed and
taken to Recovery Feed Tank. Analyser vapours are condensed in the Falling
Film Evaporators in the Integrated Evaporation Section. The condensed
Analyser vapours are taken to Rectifier Feed Tank. Rectifier-column, which
operates under pressure, concentrates the condensate of Analyser column to
95% v/v concentration. Condensing steam provides energy to rectifier
column through a vertical Thermosiphon reboiler. Fusel Oil Draws are taken
from appropriate trays and fed to Recovery Column. Recovery Column
concentrates the fusel oil streams and Degasifying condensate to 95% v/v
concentration. An impure spirit cut of about 2-3% of total spirit production is
taken out from the top of the recovery column. Rectified Spirit draw of 95%
v/v is taken out from the upper trays of Rectifier Column.
(B) Wash to ENA Mode: -
Following Columns will be under operation
1. Degasifying Column (Vacuum)
2. Analyser Column (Vacuum)
3. Aldehyde Column (Vacuum)
4. Pre-Rectifier cum Exhaust Column (Vacuum)
5. Rectifier cum Exhaust Column (Pressure)
6. Extractive Distillation Column (Atmospheric)
7. Simmering Column (Atmospheric)
8. Fuel oil Column.
Analyser column - Pre-heated fermented wash will be fed to Degasifying
column. There are 5 Sieve trays are present in degasifying column.
Fermented wash is stripped off alcohol by ascending vapours in Analyser
column.in this section 22 grid trays are present. Rectifier vapours provide
energy to Analyser column through a Thermosyphon reboiler. Vapours of
Degasifying column are condensed and taken to Recovery Feed Tank.
Analyser vapours are fed to the aldehyde column. The bottom product of an
analyser column is thin slop and this is feed of centrifugal decanter. The
condensed Analyser vapours are taken to Pre-Rectifier Feed Tank.
Aldehyde column – Analyser vapours are completely fed into the aldehyde
column for batter separation of impurity’s from the wash. In this column
contains 30 bubble cap trays and this column is operate under vacuum at +/-
0.57mm Hg. The temperature range at bottom of column is 55-59 ᵒc and at
top is 50ᵒc.
Pre-Rectifier column - Analyser Condensate is concentrated in Pre-
Rectifier column, which operates under vacuum. Condensing steam provides
energy to pre-rectifier column through a vertical Thermosyphon reboiler. A
Technical Alcohol cut of about 1-2% of total spirit is taken from the Pre-
Rectifier column.
Extractive distillation column - Concentrated alcohol draw from Pre-
Rectifier column is fed to Extractive distillation column for purification.
Dilution water in the ratio of 1:9 is added in this column for concentrating
higher alcohol at the top. Top of this column is condensed in its condensers
and fed to recovery feed tank while bottoms are fed to Rectifier cum Exhaust
Column for concentration.
Rectifier Column - Rectifier Column Operates under pressure and
condensing steam provides energy to this column through a vertical
Thermosyphon reboiler. Technical Alcohol cut is taken out from the top of
this column while ENA draw is taken out from appropriate upper trays and
fed to Simmering Column after cooling. Fusel Oil build up is avoided by
taking fusel oil draws from appropriate trays.
These fusel oils along with the condensate of Degasifying & Extractive
Distillation columns are fed to fusel oil column for concentration. A
technical alcohol cut is taken out from the top of this column.
Simmering Column –simmering column is operated under high reflux for
better separation of methanol and di-acetyls. Final ENA product draw is
taken from the bottom of this column.
Fusel oil Column – The fusel oil build up in the rectifying column along
with Degasifying & Extractive Distillation columns are fed to the ED
condensate tank. from the condensate tank feed is fed to the fusel oil column
which is operated under atmospheric pressure. there are 50 bubble cap trays
present in the column.
Parameter
Fermenter wash 47942 kg/hr
Slurry to Fermenter 59781.6kg/hr
PRC Top Pressure 0.250
PRC Rs Draw 7605
R/c Top Pressure 1.960
Rc Draw 7239.4
Decanter section
Specifications
Maximum Bowl Speed 2500 RPM
Operating speed 2451 1/minimum
Inside bowl diameter 530 mm
Bowl material 316 SS
Operating Pressure 0.5-0.6 bar
Operating temperature 65ᵒc
Permissible Density 1.3 kg/dm3
Feed Spent wash
Outlet-(Clarified Liquid) Thin Slop
Solid/Sludge Cattle feed(Wet Cake)
A decanter centrifuge (also known as solid bowl centrifuge) separates
continuously solid materials from liquids in the slurry, and therefore plays an
important role in the wastewater treatment, chemical, oil, and food
processing industries, distillery. There are several factors that affect the
performance of a decanter centrifuge, and some design heuristics to be
followed which are dependent upon given applications.
Operating principle
The operating principle of a decanter centrifuge is based on separation
via buoyancy. Naturally, a component with a higher density would fall to the
bottom of a mixture, while the less dense component would be suspended above
it. A decanter centrifuge increases the rate of settling through the use of
continuous rotation, producing a g-force equivalent to between 1000 and
4000 G's. This reduces the settling time of the components by a large
magnitude, whereby mixtures previously having to take hours to settle can be
settled in a matter of seconds using a decanter centrifuge. This form of
separation enables more rapid and controllable results.
How does it work
The feed product is pumped into the decanter centrifuge through the inlet. Feed
goes into a horizontal bowl, which rotates. The bowl is composed of a
cylindrical part and a conical part. The separation takes place in the cylindrical
part of the bowl. The fast rotation generates centrifugal forces up to 4000 x g.
Under these forces, the solid particles with higher density are collected and
compacted on the wall of the bowl. A scroll (also screw or screw conveyor)
rotates inside the bowl at a slightly different speed. This speed difference is
called the differential speed. This way the scroll is transporting the settled
particles along the cylindrical part of the bowl and up to the end conical part of
the bowl. At the smallest end of the conical part of the bowl, the dewatered
solids leave the bowl via discharge opening. The clarified liquid leaves through
a paring disc (internal centripetal pump).
