This is a brief report of Ethanol Distillery situated in Mirpurkhas, Sindh, Pakistan.
It defines the Distillation Process, CO2 Liquification Process, Formation of Bio Gas from Molasses, Water Purification Plant, and Boiler working in Unicol Distillery.
Internship Report of Unicol Mirpurkhas (Ethanol Distillery)
1. Report of Internship
In Unicol Limited Mirpurkhas
Intern Name: Talal Khan
Email: mtkg28@gmail.com
Technology: Chemical Engineering
University: Mehran University Of
Engineering and Technology,
Jamshoro (MUET)
Industry: Unicol Limited
Mirpurkhas
2. Preface
1) Introduction
2) Fermentation and Distillation Plant
3) CO2 Plant
4) RO Plant
5) Boilers and Turbines
6) ETP (Bio Gas Plant)
7) Conclusion
Introduction
Unicol Limited is situated in the vicinity of Mirpurkhas; it is 15
minutes drive from Mirpurkhas on the Umerkot road in the
neighborhood of Mirpurkhas Sugar Mill.
3. Taken from the Google Maps
The main products of this industry are Alcohol with different
percentages (95%-100%) exported all over the world.
Aside from the Alcohol it also contain different type of plant to make the
main product maximum and efficient like it contain CO2 Plant which
consumes the byproduct of Fermentation process (Carbon Dioxide)
It contains ETP which treats the spenst wash and gets Bio gas which is used
to burn Boilers which power industry up and nothing is useless in this
industry it also contains RO plant which provides fine purified water.
All these processes will be discussed in detail. Starting from the first
Fermentation Process
Introduction:
The main process of Unicol Limited is Fermentation and
Distillation so it is considered as very important.
Fermentation is the process in which a substance breaks down into a simpler
substance. Microorganisms like yeast and bacteria usually play a role in
4. the fermentation process, creating beer, wine, bread, yogurt and other
foods. Fermentation comes from the Latin word fermenter, meaning “to
leave.”
Process
Step1: Molassesto the Plant
The Raw Material (Molasses) is transported to the Unicol by different
industries and stored in Pits and Storage tanks (Unicol has 10 storage
tanks of 15,000metric tons capacity)
Step2: Analysesof Flow and control
From the pits and storage tanks, the Molasses is moved to the plant by
the help of the Pumps (Centrifugal, Gear) initially Total Flow Indicators
and valves are installed to control and analyze the Fluid (Molasses)
which also indicates the Brix percentage of the Molasses.
Step3: Mixing
The fluid is then diluted in Static Mixer with water and sludge and the
process of mixing reduces the viscosity of the fluid (Molasses) and raises
the temperature
Step4: PH Adjustment
Then the fluid goes to the Acid tank where H2SO4 is mixed with the
fluid which lowers the PH of the Molasses from 9.5 to 4.5
Step5: Purification
From the acid tank Molasses goes directly to the Decanter where, by the
action of gravity dust particles, debris etc are settled down and
separated (Sedimentation) with the help of pump and moved to a
separate decanter then it is sent to another decanter for the same
process
5. Step6: Mixing
Again Mesh goes through a mixer where water is mixed with it in a
large quantity
Step7: Pre fermenters
Then the molasses is sent to the Prefermenters where Urea, Sodium
Fluoride, Yeast and Anti-Foaming Agents are fed into it.
Antifoaming agents are used to reduce foaming layers in the process
that cause less evaporation and less heat transfer
Step8: Fermentation
The Final step in which the mesh is moved to the Fermenters where
process of fermentation occurs and produces alcohol and CO2
C6H12O6 → 2 C2H5OH + 2 CO2 (In the presence of yeast)
Distillation Process
Once after the formation of alcohol the process of distillation takes
place
Distillation is the process of separating the component or substances
from a liquid mixture by selective evaporation and condensation.
Distillation may result in essentially complete separation (nearly pure
components), or it may be a partial separation that increases the
concentration of selected components of the mixture.
The same process carried out in this industry the alcohol is purified and
concentratedin Distillation columns
The Liquid first travels to the heat exchanger (Shell and Tube) and
attains the temperature and then the liquid is transported to the column
where evaporation takes place and consecutively liquid passes through
6. different columns resulting in purification and increase in the
concentration of alcohol.
Unicol produces three type of Alcohol percentage A grade (99.9% Pure
Alcohol) B grade (95% and 96.5%).
CO2 Plant
The CO2 is a byproduct of the fermentation process and releasing it is
harmful to humans and other living things.
In Unicol CO2 is Liquefied and then transported to the beverage
industries.
The Process of purificationand liquefaction of Carbon Dioxide is as
follows
Step1: Scrubbers
When raw Carbon Dioxide is transported to the Plant. It first goes to the
Scrubber where it is washed with the Water, Ethyl Alcohol is removed
from it (As Ethyl alcohol is soluble in the water)
After two columns of KMnO4, another Scrubber is installed which
further removes impurities.
Step2: KMnO4 Columns
KMnO4 is a strong oxidizing agent and removes the inorganic
impurities attachedwith the Carbon Dioxide. It also consist of two
columns (Two Steps)
Step3: Low-PressurePurifiers
The gas then goes to the Low-Pressure Purifiers where inorganic gases
are separated with the help of the Activated Carbon
7. Step4: Compressors
The Gas goes to compressors where the velocity of the gas increases and
the gas is moved to the forward Vessel
Step5: Purifier Vessel
Again with the help of the Activated Carbon, the Gas is further purified
in the purifier vessels
Step6: Drying Vessel
Drying vessel removes the water from the CO2 and makes it fully ready
to be liquefaction
Step7: Liquefaction
Then the gas moves towards the Shell and Tube Heat exchanger and by
the help of Freon gas the Carbon Dioxide changes its phase and
Liquefies at -80*C
This Liquefied gas is sold to the Beverage industries and Also food
preservation purpose.
RO (Reverse Osmoses) Plant
Introduction:
The main functionof RO (Reverse Osmoses) Plant is to make water
feasible for drinking and energy generation purpose.
Process
Step1: Sand Filters
8. The untreated water comes from the Cooling Towers and goes through
couple of Sand Filters by which the dust particles separate and water
cleans physically
Step2: Chemical Dozing
After the Sand Filters, the Chemical are dozed into the water for
different purposes like
H2SO4 is Dozed to maintain PH
Anti-Foaming Agents are dozed to reduce foam layers
Biocides for Bacteria and Fungi
The chemicals are dozed with the Chemical Dozing Pumps
Step3: Bag and CartageFilters
Bag and Cartage filters remove more dust and settled particles from the
water and make it clean for the forward process
Step4: Membranes
The important part of any RO Plant is Membranes and it is responsible
for the cleaning purpose most of the time.
Likewise, the water from the Cartage and Bag Filters goes to the Pumps,
the pressure of water is increased and then it is supplied to the
Membranes
Where most of the impurities of the water removes by the polymer
sheets present in the Membranes
Step5: Bed Filter
Water is purified but need to regulate the TDS (Total Dissolved Salts)
Bed Filter resolves this problem and removes the TDS from the Water
Now finally the water is ready for drinking as well as well for the
energy generation purpose.
9. It is transported to Boiler and other departments where Water is needed.
Boiler and Turbines
Introduction: The water exited from the RO (Reverse Osmoses) Plant is
transported to the Boilers where it is heated and used to generate
Electricity.
Process
The Boiler is heated by the Furnace and for fuel purpose, Baggas and
Bio Gas are used. First, the Baggas is fed into the furnace with Bio Gas
with the 30% and 70% ratio respectively, and then the burning process
takes place several valves are installed to control different factors
including safety valve ( which automatically vent the pressure if
exceeds the limit )
ID (Induced Draft) fans are used to in the air for better burning in the
furnace and FD (Forced Draft) Fans are used to vent the exhaust gases
Boiler changes the phase of water from liquid to gas and this gas is
transported to the Turbines and Distillation Plant.
Turbine:
The Turbine is a device which moves and helps to generate Electricity
The Steam collected from the boiler is moved to a turbine which rotates
at 1000 rpm and in result moves the Generator shaft which creates
Electricity.
The Capacity of Turbine was 4.5 MW per day and it can fulfill all the
Electrical needs of the Industry withoutany interruption.
10. ETP (Effluent Treatment Plant)
Introduction: More commonly it is called as the Bio Gas Plant. It has
two Benefits First It treats the Waste before disposing of and second it
manufactures the Bio Gas which is used to generate electricity.
Process:
Step1: Raw Material
Spent wash is the waste from the Distillation process and was no more
useful but after this process, it is now raw material, not a waste.
The Spent Wash from the Distillation Plant is Stored in pits and then
moved to the main Process
Step2: Digesters
By the help of the pumps, the liquid is transported to the Digesters
(Large round tanks of Capacity 11350 metric Ton) where the generation
of Bio Gas occurs with the time (In digester sludge settles down by the
action of gravity).
Step3: Degassing Tanks and Laminar Separator
The overflow is collected into Degassing Tanks where sludge settles
down and then moves towards the Laminar Separator which separates
the Sludge from the Liquid
Step4: Post Digesters
The overflow liquid after separation of the sludge goes to the Post
Digesters which try to get more Bio Gas out of the liquid.
Step5: Gas Collection
After gas generates in the Digesters the gas is washed with the water
and transported to the Boiler.
11. Step6: Treatment process
After this whole process the COD of the liquid lowers down and now it
is discharged into the atmosphere
Laboratories
There are two main laboratories
Main Laboratory is which analyze the quality and quantity of the
alcohol as well as the Brix.
Bio Gas Laboratory analyzes the spent wash by different Tests.
Conclusion
Overall it was a great experience to get into the Unicol
Limited, Mirpurkhas and there were a lot of opportunities to
learn and understand different processes. The Staff was co-
operative and the environment was amazing. It will be an
unforgettable experience.
Thanks for giving us opportunity and thanks for your co-
operation.