NOON SUGAR MILLS LIMITED BHALWAL
ADVISOR Mr. Dr. Moinuddin Ghauri
Submitted by Mr. Muhammad Shahid CIIT/SP09-BEC-031/LHR SESSION 2009-2013 Submission Date July 21, 2012
Department of Chemical Engineering COMSATS INSTITUTE OF INFORMATION TECHNOLOGY LAHORE
Dedication
I dedicate all my efforts to Almighty Allah, The creator of the universe And The Holy Prophet (PBUH), The cause of the creation of the universe To my parents, The symbol of love and kindness And To my teachers, The light of knowledge in darkness of ignorance To my friends, The pillars of trust and support, And To my relatives, The motivators and encouragers.
Acknowledgement
I am thankful to Almighty Allah who has blessed us with the courage, strength and wisdom so that we have been able to complete this internship report, with the help HE has bestowed upon us. I am greatly thankful to Mr. Dr. Asad U Khan (HOD Department of Chemical Engineering, COMSATS Lahore) and Mr. Dr. Moinuddin Ghauri (Associate Professor, Department of Chemical Engineering COMSATS Lahore) who kindly provided me opportunity to check my abilities in a good organization like Noon Sugar Mills Ltd. (Distillery Section). It was valuable experience and interesting work for me and it was really a delightful job. I extremely thank for supporting persons Mr. Naveed Akhtar (Resident Director, Noon Sugar Mills Ltd, Bhalwal), Mr. Ehsan Ahmad (General Manager Distillery, Noon Sugar Mills Ltd. Bhalwal) and Mr. Hafiz Muhammad Hamid (Production Manager Distillery, Noon Sugar Mills Ltd.) The assistance and guidance of Mr. IMTIAZ AHMAD (Chief Chemist Distillery, Noon Sugar Mill Limited Bhalwal) throughout the internship duration and especially for this internship report has positioned me as a knowledgeable, hardworking and flexible personality so that I can perform better in the Practical field life. I am thankful to be for injecting such knowledge in my mind and for the guidance, he has given to me. I am also thankful to my dear parents who have assisted me financially, mentally and physically so that today I am proud to call myself as educated and an important part of the society and will be looking forward to make positive contributions to the society with the knowledge that I have acquired. Here I must not forget to thank the Staff Members NSM (Distillery) Ltd. Bhalwal, Sargodha who have helped me to learn the nature of work being done in the organization and also helped me to scrutinize what I have learnt in our classroom settings from a practical point of view. Especially I want to acknowledge Shift Chemist Mr. Bilal Ahmad, Shift Chemist Engr.
Mr. Muhammad Ali, for their keen guidance during the internship.
Sr.No.
Content
Page No.
CHAPTER 01 HISTORY &BACKGROUND 1.1
Sugar Industry
01
1.1.1
Waste Products from Sugar Industry
02
1.1.1.1
Molasses
02
1.1.1.2
Bagasse
02
1.1.1.3
Vacuum Filter Cake (Mud)
02
1.2
NOON SUGAR MILLS LIMITED
02
1.3
NOON SUGAR MILLS LIMITED (DISTILLERY)
02
1.3.1
Ethyl Alcohol
03
1.3.1.1
Industrial Grade (Hydrous)
03
1.3.1.2
Fuel Grade (Anhydrous)
03
1.4
Awards and Certificates
04
1.5
Mission Statement
04
1.6
Objectives
04
CHAPTER 02 SOME IMPORTANT DEFINITIONS 2.1
Brix
05
2.2
Invert Sugar
05
2.3
Massecuite
05
2.4
Molasses
05
2.4.1
Heavy Molasses
05
2.4.2
Light Molasses
05
2.5
Normal Weight
06
2.6
POL
06
2.7
Reducing Sugar
06
2.8
Sucrose
06
2.9
Total Sugars
06
2.10
Composition of Molasses
07
2.11
Molasses for Alcohol
07
2.12
Fermentation
07
2.13
Distillation
07
CHAPTER 03 Manufacturing of Industrial Ethanol (C2H5OH) by Fermentation and Distillation 3.1
Introduction
08
3.2
Products from Distillery
08
3.3
Raw Material
08
3.3.1
Sources of Water
08
3.3.2
Sources of Molasses
09
3.3.2.1
Molasses from NOON SUGAR MILLS LTD.
09
3.3.2.2
Molasses from Other Sugar Mills (Purchased Molasses)
09
3.3.2.3
Molasses Storage and Transportation from Decantation Pit
09
Block Diagram for Storage and Transportation of Molasses
11
Sections of Distillery
12
3.4 CHAPTER 04
UTILITY SECTION 4.1
Introduction
13
4.2
Importance of Water in Alcohol Industry
13
4.3
Process Water
13
4.3.1
Storage
13
4.3.2
Working and Utilization
14
Process flow Diagram of Process Water Circuit
15
4.4
Cooling Water
16
4.4.1
Supply
16
4.4.2
Storage
16
4.4.3
Working and Utilization
16
4.5
Process Air
17
4.5.1
Supply and Storage
17
4.5.2
Working and Utilization
17
4.6
Instrument Air
17
4.6.1
Storage and Supply
17
4.6.2
Working and Utilization
18
Process flow Sheet for Instrument Air
19
4.7
Chilling Unit
20
4.7.1
Supply and Storage
20
4.7.2
Working and Utilization
20
4.7.3
Precautions
20
4.8
Tests Regarding to the Utility Section
21
4.8.1
Water Analysis
21
4.8.1.1
PH Test
21
4.8.1.2
Hardness Test
21
CHAPTER 05 Dilution Section 5.1
Introduction
22
5.2
Chemicals Used in Dilution
22
5.2.1
Molasses
22
5.2.2
Process Water
22
5.2.3
Sulfuric Acid (H2SO4)
22
5.2.4
Process Air
22
5.2.5
Antifoaming Agent
23
5.3
Process of Dilution (Substrate for fermentation)
23
Process Flow Sheet for Dilution Section
24
5.4
Test Regarding the Dilution Section
25
5.4.1
Determination of brix of Molasses
25
5.4.2
Determination of Total Sugar in Molasses
25
CHAPTER 06 Pre-Fermentation Section 6.1
Introduction
27
6.2
Aerobic Fermentation
27
6.3
Procedure of Pre-Fermentation
27
6.4
Shutdown Procedure of Pre-Fermentation
27
Process flow Sheet for Bub Vats (pre-fermentation)
28
CHAPTER 07 Fermentation Section 7.1
Fermentation
29
7.2
Alcoholic Fermentation of Molasses
29
7.3
Factors Affecting Fermentation Enzymes
29
7.4
Fermenters
29
7.4.1
Fermenter capacity
29
7.5
Chemical Equations
30
7.6
Chemicals Used during Fermentation
31
7.6.1
Yeast
31
7.6.2
Sodium Fluoride (NaF)
31
7.6.3
Phosphoric Acid (H3PO4)
31
7.6.4
Urea (H2N-CO-H2N)
32
7.6.5
Calgon (Sodium hexa Meta Phosphate)
32
7.7
Substrate Preparation
32
7.8
Fermentation procedure
32
Graphical Representation of Brix and
33
Temperature as a function Time Process flow Diagram of Fermenters Setup
34
7.9
How to Increase Alcohol Yield?
35
7.10
Shutdown procedure of Alcoholic Fermentation
35
7.11
Benefits of Fermenter Cooling
35
7.12
Laboratory Analysis Regarding Fermentation Section
36
7.12.1
To count the cells of fermentation in Bub Vats
36
7.12.2
Strength of Alcohol in Fermenters
36
7.12.3
PH of Bub Vats and Fermenters
36
7.12.4
Brix of Bub Vats
37
CHAPTER 08 Distillation Section 8.1
Distillation
38
8.2
Types of Distillation
38
8.2.1
Fractional Distillation
38
8.2.2
Vacuum Distillation
38
8.2.3
Steam Distillation
38
8.2.3.1
Stripping Column
39
8.2.3.2
Rectifying Column
39
8.2.3.3
Reflux
39
8.3
DISTILLERY-I
39
8.3.1
Vacuum Column
D-510
39
8.3.2
Low Boiling Column D-530
39
8.3.3
Rectification Column D-540
40
8.3.3.1
Rectified Alcohol
40
8.3.3.2
Low Grade Alcohol
40
8.3.3.3
Fusel Oils
40
Process Flow Diagram of Distillery-I (D-510 & D-530)
41
Process Flow Diagram of Distillery-I (D-540)
42
8.4
Distillery-II
43
8.4.1
Introduction
43
8.4.2
Operational procedure
43
Process Flow Diagram of Distillery-II (D-510)
44
Process Flow Diagram of Distillery-II (D-540)
45
8.5
Laboratory Analysis Regarding Distillation Section
46
8.5.1
To check the strength the Rectified Alcohol
46
8.5.2
Time test KMnO4 for final product
46
8.6
Molecular Sieve Dehydration Plant
47
8.6.1
Process Description
47
8.6.2
Advantages of System
47
CHAPTER 09 Effluent Treatment Plant (ETP) 9.1
Introduction
48
9.2
Bio-Gas Plant
48
9.2.1
BOD (Biological Oxygen Demand)
48
9.2.2
COD (Chemical Oxygen Demand)
48
9.3
Procedure
49
9.4
Usage of Produced Bio-gas
49
CHAPTER 01 HISTORY &BACKGROUND 1.1
Sugar Industry Sugar is a broad term applied to a large number of carbohydrates present in many plants and characterized by a more or less sweet taste. The primary sugar, glucose is a product of photosynthesis and occurs in all green plants. In most plants, sugar occurs as a mixture that cannot readily be separated into components. In the sap of some plants, the sugar mixtures are condensed into syrup. Juices of sugarcane (Saccharum officinarum) and Sugar beet (Beta Vulgaris) are rich in pure sucrose. These two sugar crops are the main sources of commercial sucrose. The Sugarcane is a thick, tall, perennial grass that flourishes in tropical and subtropical regions. Sugar synthesized in the leaves is used as a source of energy for growth and is sent to the stalks for storage. It is the sweet sap in the stalks that is the source of sugar as we know it. The reed accumulates sugar to about 15 percent of its weight. Sugarcane yields about 2,600,000 tons of sugar per year. The Sugar beet is a beet root variety with the highest sugar content, for which it is specifically cultivated. About 3,700,000 tons of sugar is manufactured from sugar beet. Sugar is not only used as a constituent in industrial and homemade food, but also as raw material in fermentation to produce ethyl alcohol, butyl alcohol, glycerin and citric acid. Sugar is also an ingredient in transparent soaps and can be converted to esters which yield tough, insoluble and infusible resins.
Following are the Processing Steps while making Sugar Cane is first washed to remove mud and debris. After washing, Cane is chopped and shredded by crushers. Juice is extracted from cane either by pressing the cane through series of mills or by diffusion i.e. leaching. Juice is then clarified to remove floating impurities. Clarified juice is then heated in pan evaporator for concentration and it is concentrated up to 65-68 BRIX. A mixture of syrup and Crystals is obtained which is known as MASSECUITE. This Mixture is then centrifuged and crystals are separated. The thick liquid left behind is known as MOLASSES, which is the basic raw material for the production of Alcohol.
1.1.1
Waste Products from Sugar Industry
1.1.1.1
Molasses:
Molasses may be used for the production of power alcohol and Molasses is also used for feed stock.
1.1.1.2
Bagasse:
This is also a by-product of the industry. Bagasse is used as a source of energy fuel in sugar industry for sugar processing and also used for making medium density fiber board (MDFB).
1.1.1.3
Vacuum Filter Cake (Mud)
Mud is also a by-product of the industry and is used as fertilizer by farmers.
Production Sector 1.2
NOON SUGAR MILLS LIMITED
The company was incorporated in 1964 as a public company listed on all Stock Exchangers of Pakistan for setting up of a plant for manufacturing of white sugar, in the province of Punjab. The plant went into production in 1966 with a daily crushing capacity of 1500 MT of sugarcane per day, which has been raised to 4000 MT per day in 2002. Further extension to 8000 TCD is carried out in two phases successfully since 2007-2008 crushing season.
1.3
NOON SUGAR MILLS LIMITED (DISTILLERY)
An Alcohol Distillery of FRENCH origin was installed during 1986 with a production capacity of 50,000 liters per day. Another facility with an option to provide either 30,000 liters per day Industrial or Fuel grade ethanol was added in 2002. A new fuel ethanol plant of 100,000 liters per day, based on MOLECULAR SIEVE TECHNOLOGY has been added in 2005. An Effluent Treatment Plant employing the Canadian technology of ABV Bio-Gas reactors has been installed since 1997, to use its bio-degradable waste water as a renewable source of energy to replace 70% of fuel oil/natural gas, for generation of process steam. This has also enabled the company to fulfill its obligation towards reducing the environmental pollution.
1.3.1
Ethyl Alcohol
1.3.1.1
Industrial Grade (Hydrous) Guaranteed Product specifications for Export of Industrial Grade Alcohol (BSS. 507 / 1996-ISO-R 1388/1970)
1.3.1.2
Alcohol Contents
Minimum 95% by Volume at 15°C
Aspect
Clear, Colorless, Free from Suspended matter
Odor
Not Foreign
Dry Matter
Maximum 10gr/hl (100ppm)
Acidity
Maximum 7gr/hl (70ppm) as acetic acid
Esters
Maximum 25 gr/hl (250ppm) as ethyl acetate
Aldehydes
Maximum 20 acetaldehyde
Higher Alcohol
Maximum 25 gr/hl (250ppm)
Furfurol
No detectable
Methanol
Maximum 10 gr/hl (100ppm)
gr/hl
(200ppm)
as
Fuel Grade (Anhydrous)
Ethyl Alcohol or Ethanol, non-denatured, fermented from cane or cane molasses with alcohol strength minimum 99.7% by volume at 15°C in bulk, with following specifications.
Aspect
Clear and Colorless liquid free from suspended matter
Ethanol plus higher 99.7% min saturated alcohols
1.4
Water Contents
0.3% max
Acidity as Acetic acid
7gr/hl
Esters as Ethyl Acetate
25gr/hl
Methanol
10gr/hl
Higher Alcohols
25gr/hl
Chloride Contents
<2 mg/l
Density at 20°C
0.789 kg/l
Awards and Certificates
The distillery is ISO 9001 certified since 1998, which upgraded to ISO-9001-2000.
1.5
Mission Statement
Noon Sugar Mills Ltd. is committed to continue its sustained efforts toward optimizing its resources through updated technology, Staff motivation and good corporate governance so as to INSHA ALLAH maintain its tradition of high yield and handsome returns to its shareholders on their investments in the company.
1.6
Objectives
The objectives of the company are:
Total quality focus to meet customer’s requirements. The highest standard of business ethics. To carry on the business ethics. To carry on the business at best possible level. To guarantee performance of contracts by members or persons having dealing with the company.
CHAPTER 02 SOME IMPORTANT DEFINITIONS 2.1
Brix
This is the concentration of dissolved solids material per unit volume in any solution. Unit division of the scale of a brix hydrometer which when placed in a pure aqueous sucrose solution indicates the %age by weight of solids in the solution at standard temperature. The reading obtained as an approximation of its %age by weight of total soluble solids.
2.2
Invert Sugar
A mixture of approximately 50% glucose (dextrose) and 50% fructose (laevulose) obtained by hydrolysis of sucrose.
2.3
Massecuite
The mixture of crystals and mother liquor discharges from the vacuum pan is known as massecuite.
2.4
Molasses
The waste mother liquor of the sugar industry from which the sugar could not be extracted by crystallization is known as molasses. It still contains sugar contents up to 50%. OR It is the mother liquor in the massecuite which is separated from the crystals by mechanical means.
2.4.1
Heavy Molasses
The mother liquor which is separated before the washing of crystals begins is termed as heavy molasses. The heavy molasses obtained from the last grade of massecuite is termed as final molasses or waste molasses.
2.4.2
Light Molasses
The mother liquor which is separated after washing is termed as light molasses. Molasses is one of the most used substrate (a substance ready for reaction for specific activities) in the manufacturing of fermentation alcohol particularly tropical countries where sugarcane is
grown. It is fermented to ethyl alcohol or ethanol in accordance with the reaction of Hexose sugar. C6H12O6 +water +Yeast +nutrient (urea) —> 2C2H5OH +5CO2 +Heat of reaction CO2 is produced during fermentation at rate about 160 kg per 1000 kg of molasses. Specific gravity of molasses =1.43 PH
=6
The yield of molasses per ton of cane is usually approximately 2.7% but it can be affected by the quality of sugarcane.
2.5
Normal Weight
The weight of pure dry sucrose which dissolved in water to a total volume of 100 ml at 20°C and read at the same temperature in a tube 200mm long, gives a reading of 100 degree on a saccharimeter scale. The normal weight of sucrose is 26.00gms.
2.6
POL
The value determined by the direct or single polymerization of the normal weight solution in a saccharimeter. The term used as if it was real substance.
2.7
Reducing Sugar
The term denotes the reducing substance in cane or its products, calculated as invert sugar.
2.8
Sucrose
The pure disaccharide C12H22O11, also known as saccharose or cane sugar. In sugar work the term sucrose means the result obtained analytically by clergent or double polymerization method.
2.9
Total Sugars
Sucrose plus reducing substances expressed as invert sugar.
2.10
Composition of Molasses
%Age
Average%
Compounds
17-25 30-40 04-09 05-12 02-05 07-15 02-06 02-08
20 35 07 09 04 12 4.5 05
Water Sucrose Dextrose (glucose) Fructose Other Carbohydrates Ash Nitrogenous Compounds Non Nitrogenous Compounds
.1-01
0.4
Wax, Pigments, Vitamins
2.11
Molasses for Alcohol
Molasses used for the production of alcohol should, in general have following qualities. High in fermentation Low in ash Because these can acts as an inhibitor of the growth of yeast cell and also in the heat exchanging and distillation columns. Low in gums High in assailable inorganic nitrogen and in P2O5, since this is required for the yeast growth. PH value should be 5.5 to 6.0. Due to high or low PH the final product may be contained some impurities like acetic acid in it.
2.12
Fermentation
The conversion of the compound to another compound by the action of biological microorganisms, which involve a chemical reaction, is known as fermentation.
2.13
Distillation
It is a technique which is used to separate a mixture of two or more materials (usually liquids) that differ in their boiling points.
CHAPTER 03 Manufacturing of Industrial Ethanol (C2H5OH) by Fermentation and Distillation 3.1
Introduction
Noon Sugar Mills Ltd. is located in Bhalwal, District Sargodha. It was established in 1966. After the production of sugar from sugarcane, Molasses is produced as a by-product. For the conversion of sugar present in the Molasses into Industrial Alcohol, Noon Sugar Distillery was established in 1985 and started commercial production of Ethanol from Molasses.
3.2
Products from Distillery
Basically, two kinds of products are produced from distillery, which are: Rectified Alcohol of minimum 96% Strength Low Grade Alcohol of minimum 90% Strength Some part of Rectified Alcohol produced is sold locally to Wah Nobel Acetates Laboratories, other local industries and Homeopathic license holder. The major part of the Rectified Alcohol production is exported to different countries like ENGLAND, FRANCE, JAPAN, and SWITZERLAND etc.
3.3
Raw Material
The basic raw material required for the production of ethyl alcohol or ethanol includes:
3.3.1
Water Molasses Sulfuric Acid Yeast Nutrients (Urea, Phosphoric acid) Air
Sources of Water
There are three main sources to supply water in the distillery. Canal Water (Hardness 70-100ppm) Soils Tube Well Saline Water (Hardness 400-600ppm) 7 Chak Tube Well nearby main lower Jhelum Canal Branch (Sweet/Soft Water)
3.3.2
Sources of Molasses
Molasses which is the basic raw material for the production of Ethanol is taken from the following sources: NOON SUGAR MILLS LTD. Other Sugar Mills.
3.3.2.1
Molasses from NOON SUGAR MILLS LTD.
Molasses from Noon Sugar Mills Ltd. is stored in Buffer Pit. Its average Brix is 92. Brix can be defined as the ―Concentration of dissolved solid material per unit volume in any solution.‖ Brix Hydrometer is used to check the brix of molasses, which when placed in a pure aqueous sucrose solution, indicates the %age by weight of solids in a solution at a standard temperature.
3.3.2.2
Molasses from Other Sugar Mills (Purchased Molasses)
Purchased Molasses is decanted in decantation pit. Decantation of molasses takes place by the following steps: Vehicle loading weight is taken on NSM Distillery Weigh Bridge. Weigh Bridge has a capacity of 50 ton. Unloading is started in decantation pit. During winter Steam is provided to minimize decantation time. During decantation, three samples are collected to check the quality of molasses. First sample from the top, second from the middle and third from the bottom of the tank.
3.3.2.3
Molasses Storage and Transportation from Decantation Pit
As molasses is viscous material, so its transportation is carried out through gear pumps i.e. positive displacement pump. These types of pumps are used for high head. Storage of molasses is done in molasses storage tanks and each tank has different capacity. There are seven tanks for storage of molasses.
Sr. No
Tank R-300
No Internal Dia. Total (m) Height (m)
Filled level Total Capacity 1m from top (MT)
01
A
19.97
12.50
11.50
5483.00
02
B
19.97
12.50
11.50
5483.00
03 C
17.97
12.17
11.17
4323.00
04 D
17.97
12.17
11.17
4323.00
05 E
29.97
11.38
10.38
11244.00
06 F
22.97
12.27
11.27
6541.00
07
G
22.97
12.27
11.27
6541.00
08
Buffer Pit
2.20
1.20
2937.00
09
Decantation Pit
1.28
129.00
R-300 F
R-300 G
Decantation Tank
R-300 D
R-300 C
R-300 E
Buffer Pit
R-300 A
R-300 B
To dilution
Block Diagram for Storage and Transportation of Molasses
3.4
Sections of Distillery
Distillery plant operation is mainly divided into following sections.
Utility Section Dilution Section Pre-Fermentation Section Fermentation Section Distillation Section a) Vacuum Distillation Section b) Pressure Distillation Section c) MSDH (Molecular Sieve Dehydration) Plant
CHAPTER 04 UTILITY SECTION 4.1
Introduction
The section where supply arrangements and storage of raw material is controlled is known as utility section of the plant. There are following circuits involved in the utilities section.
4.2
Process Water Circuit Cooling Water Circuit Instrument Air Circuit Process Air Circuit Chilling Unit
Importance of Water in Alcohol Industry
Water consumption has a great importance in industrial processes all over the world. It is a substrate for the fermentation. Microorganisms act in aqueous media and the fermentation industry is basically depending on the large supply of water. Water is required for the preparation as Mash (wash) also for the cooling purpose. In the United State it is indicated that 65 liters of water is required for the production of one liter of Alcohol while during summer the actual consumption is higher than this quantity.
4.3
Process Water
Process water has much importance in distillery. The water used in processing i.e. in dilution of molasses and for washing purpose, is called Process Water. Process water is also used in cooling circuit.
4.3.1
Storage
The water coming from different sources is stored in the reservoir R-620 having capacity 600 m3 and height 200 cm. It has a temperature about 27-30oC (according to weather condition). The level range of this storage reservoir should have 50-200 cm. if it is less than 50cm then there may have the air lock in the pump and if it exceeds than 200cm then the overflow creates problems. The maintenance time is about 1 year.
4.3.2
Working and Utilization
From the reservoir R-600 the water is pumped through P-620A and B (one stand by) to the overhead process water tank R-302. The overflow of R-302 is received in R-620. Now the water from R-302 is used for many purposes. During the dilution process, it is mixed with other raw materials e.g. Molasses, Sulfuric Acid. Here water is used for mixing purpose or to lower down the brix contents. Other uses of water are as follows:
Used for vacuum pump to lower down its temperature. Used for cleaning action to remove mud from liquidated equipment e.g. Fermenters,
Heat Exchangers etc. For firefighting purposes, in case of emergency. In compressors (C-600 A,B) In Chilling Unit (R-401) In laboratories Used for cooling purpose, at the outer surface of BUB VAT 405- A, B, C and D by a showering coil.
In earlier days, sand filters (S-631 A/B) were used in the industry to remove the dust and other sand particles from the water. But they take too much time to filter the water. So currently they are out of use. It is necessary to filter the water to remove mud and also to lower down its hardness value for the efficient process. If it is not so, then we may face many problems in dilution, fermentation, as well as in distillation. In dilution, mixing may not take place. During fermentation, brix cannot be maintained. Side reaction may occur. PH and temperature can also be affected by the poor quality of water. The Shift In-charge should be vigilant for regular supply of process water. In case of power failure or mechanical job the alternate arrangements should be made.
R-302 Overhead Tank
R-311
To dilution
CO2 Scrubber R-405 A
R-405 B
R-620 (Process Water Storage)
Process flow Diagram of Process Water Circuit
4.4
Cooling Water
The water used for cooling purpose or to control the temperature of the exothermic reaction is known as cooling water.
4.4.1
Supply
It is supplied from colony water (sweet/soft water) and from canal water. We do not mix water of hardness value about 400-600 ppm.
4.4.2
Storage
The cooling water is stored in reservoir R-630 A/B. The capacity of R-630A is 250m3 while R630B has a capacity of 400m3. The maintenance time of these storage reservoirs is about one month and the temperature of the water is about 30oC depending upon the weather condition. Height of the storage R-630A is 135 cm while minimum and maximum range level of this storage is 90-135 cm. A little storage of cooling water is also carried out in R-640 where the cooling water after its circulation is allowed to cool in open air for a while and from here it is send back to R-630A. From R630-A, water is pumped through P-630A/B/C/D to the overhead tank R-303. R-303 has a 4 times less water capacity to that of R-630A.
4.4.3
Working and Utilization
In storage of cooling water R-630A some chemicals are added. The chemical CT230H is added about 2 liters daily in the morning to kill the bacteria and to overcome the Algae problem. And after every week AL-385, AL-310 is added as required both or one of them in evening after Maghrib prayer. If we don’t add these chemicals, we face many difficulties in condenser e.g. scaling may take place or chocking of pump take place. This cooling water from R-630A is pumped through P630 A/B/C/D (one or two operational while other on standby) to the overhead cooling water storage, R-303. Before it goes to overhead tank we utilize its low temperature 30oC in heat exchangers of ten fermenters (R-406 A-J). During circulation, temperature of fermenters should be controlled. Then the circulated water again joins the line going to the overhead tank. From overhead tank R-303 send this water by gravity to water hydrant (The place from where water is distributed). A line from the hydrant, water is sent to the condensers E-516, E-517 and E-535 to cool down the temperature of Alcohol vapors. So by giving energy to water, vapors are condensed. One of the water line from hydrant goes to vacuum pump to control the temperature. We also utilize this water in cooler E-542 to cool (F-1,543 and 544) low and high grade alcohol.
Then this circulated water which becomes hot, is then directed to the showering unit or hot water tank R-640. Hot water is collected here to reduce its temperature by 10oC then it is pumped by P640 A/B to fall on the fan F-630 A/B to cool down. Above the fan (on the top) arrangement of pipe is adjusted so that water will spray in the form of thick droplets then these droplets are passed through gauze bundle and cool down by Fan. Process water could be waste (in washing purpose) but cooling water cannot as it is circulating continuously. Cooling water cannot be used as process water, as it has chemicals mixed in it.
4.5
Process Air
―The air used in the process for mixing and to provide the oxygen for growth of microorganisms is called process air‖
4.5.1
Supply and Storage
We take the process air from atmosphere and compress it in the compressor C-400 A/B/C/D. One or two are in working condition while others are standby.
4.5.2
Working and Utilization
From compressor, the air first cools down in the showering unit R-640 by cold water. Then this is cooled air is directly sent to dilution tank as well as in Bub Vat. In dilution tank air is used only for mixing purpose while in Bub Vat it is used for mixing as well as, as a source of oxygen for the growth of cells. In Bub Vat pre-fermentation occurs and controlled amount of air is used in Bub Vat. The less or excessive amount of air can damage the cells health due to which our process can be affected very badly. Process air should be free of dust so that it would not affect the mixing in dilution tank as well as in Bub Vat. Especially, the air containing the dust particles cause retardation in the reaction, taking place in Bub Vat.
4.6
Instrument Air
―The air used to control the instruments i.e. flow meters, level controllers etc. on the plant is known as Instrument Air.‖
4.6.1
Storage and Supply
The instrument air supply for plant is acquired from the atmosphere. There are four compressors C-600 A/B/C/D two of which are standby. They compress the air about 6.2 bar (total pressure). After drying we store it in R-600.
4.6.2
Working and Utilization
The compressed air from the compressor C-600 A/B/C/D, two are in working condition and two of them are standby, is send to the dryer to remove moisture contents. Here moisture is very dangerous for the instruments because the air itself with moisture wouldn’t have its own pressure. Also there is chance of rusting inside the levels. The pressure 6.2 bar is divided according to the requirement of the instruments. In distillation, the pressure is about 0.32bar to control the auto valves. In fermentation this pressure is up to 3.2bar and to control level control valves (L.C.V) this pressure is about 1.5bar. So, the distribution of pressure is adjusted according to the instruments requirement. This instrument air is also used in dilution tank R-312 C/D, Bub Vat R-405 A/B/C/D and in all ten fermenters R-406 A-J to control the level of the system. We can check the exact level of feed in the concerning tank. In the distillation columns D-510, D-530 and D-540, steam, liquid, vacuum and feed level is controlled by the level control valve and the L.C.V is controlled by this instrument air. In phase III this air can automatically controlled with the help of computer system. Instrument air should be moisture and dust free.
Air Dryer
LCV
R-406 A-j
R-405 A,B,C,D
R-312 A,B,C,D Steam value and all other Sensitive Instrum-ents
Air Storage Tank C-600 A
C-600 B
D-510,530,540
Process flow Sheet for Instrument Air
4.7
Chilling Unit
It is a unit where we cool the water up to required temperature (10-13oC), So that the exothermic reaction in the Bub Vat is controlled, and to continue the reaction in the tank.
4.7.1
Supply and Storage
We supply water from overhead tank R-302 to the chilling unit or Refrigeration unit. It is stored in the unit named R-401.
4.7.2
Working and Utilization
The water from the overhead tank R-302 is stored in the chilling unit R-401. It has the cooling coils in it, which are connected to the compressor C-401 A/B. The gas of the compressor cools that storage water in R-401. There is an auto valve for the water to enter the tank. The temperature of that chilling unit is about 12-15oC. This chilled water controls the temperature of the Bub Vat in which exothermic reaction taking place. This chilled water will acquire heat energy of the reaction and cool that feed in the Bub Vat or pre-fermenters. Rota meter controls the flow of water. To control the temperature of Bub Vat, we used ice blocks in earlier stages of this plant. It was very expensive and less efficient method. In summer, those ice blocks were consumed in 2-3 hours and we have to arrange for other one for continuous running of the plant.
4.7.3
Precautions
The water should have low temperature about 8-12oC for a successful reaction. In case of high temperature the reaction will distribute also the other parameters cannot be handled easily. In case of emergency there should be an alternative arrangement.
4.8
Tests Regarding to the Utility Section
4.8.1
Water Analysis
4.8.1.1
PH Test
To check the PH of the water, we test the sample with the help of pH meter. First of all we have to calibrate the pH meter with the help of Buffer solution of pH 7.00 and 4.00 PH
7.00
PH
4.00
Buffer
After calibration, the tube is filled with sample and put into the instrument. The pH meter will automatically give the pH of that sample. The pH of the process water must be near to 7.00.
4.8.1.2
Hardness Test
4.8.1.2.1
Procedure
We take 10ml of water from the beaker of the pH meter. We add buffer indicator one or two drops. We add 3-4 drops of Erichrome Black T. Now, we titrate the solution against EDTA.
4.8.1.2.2
Observations and Calculations
Sample
= Canal Water (process water)
Initial Reading of EDTA used
= 36.4 ml
Final Reading of EDTA used
=38.0 ml
EDTA Used
=38-36.4 =1.6ml
Hardness
=1.6× factor of EDTA =1.6× 45 =72 ppm
CHAPTER 05 Dilution Section 5.1
Introduction
In dilution Section, molasses and water are mixed in the ratio of 1:3. The main purpose of the dilution is to get the brix which is much lower than the actual brix of molasses. The main cause of dilution is to get the better yield of production. Pure molasses have very high brix.
5.2
Chemicals Used in Dilution
Following are the chemicals which are required for making the dilution of required properties.
5.2.1
Molasses Process Water H2SO4 Process Air Antifoaming Agent
Molasses
Molasses are stored in the following tanks R-300 A-G. Mainly we get molasses from R-300 A/B for use in dilution tank with pumps P-300 A/B/C (one is in operation while others are standby).
5.2.2
Process Water
The process water used in dilution is coming from R-302 (Overhead Tank).
5.2.3
Sulfuric Acid (H2SO4)
Sulfuric Acid is used to maintain the pH of the dilution. The pH maintained by acid produce such environment which kill the germicide and enhance the growth of microorganisms for fermentation. H2SO4 in measured amount is added from R-321A/B tanks. In R-321 A/B, the acid is coming from R-320. The pH is maintained up to 4.5.
5.2.4
Process Air
There are coils in the dilution tanks which are approximately 7 inches up from the bottom and having small nozzles for processing air and this air homogenizes the solution. First of all, coil is immersed in water then molasses are added for better air bubbling for mixing.
5.2.5
Antifoaming Agent
During mixing, foaming produced, which is reduced by adding the antifoaming agents in the dilution tank.
5.3
Process of Dilution (Substrate for fermentation)
Dilution is carried out on the basis of the brix of molasses obtained from different sugar mills, having different brix value. But usually it contains 85-90% brix. But our required brix is 26-27%. Following steps are involved to make substrate. Wash the dilution tank with process water. Fill the tank 10-12% with process water. Add molasses to fill the volume of tank up to 70-72%. Time of one batch of dilution preparation of required brix (25-26%) is about 39 minutes. In bottom of dilution tank, there are coils of process air which is used to mix dilution properly. Now add 50 liters of Sulfuric Acid from R-321 A/B. Mixed the solution for a specific time about 35-40 minutes. After mixing, check the brix and pH of the dilution. If brix is about 25-27% and pH is about ±4.5. Then this substrate is ready for fermentation.
R-312 B
R-312 A
R-312 C
R-312 D
H2SO4 Tank
Process Flow Sheet for Dilution Section
Process Water
Process Water
From R-300
5.4
Test Regarding the Dilution Section
5.4.1
Determination of brix of Molasses
5.4.1.1
Apparatus
Thermometer, Beakers, Brix Hydrometer, Temperature Correction Chart
5.4.1.2
Procedure
Take the 100g of molasses in 250ml beaker. Add 200ml of water and shake it with stirrer. Then shifted it into the 1000ml measuring cylinder and add water. Take the 250ml of dilution mixture and dip the brix hydrometer of range 0-10 in it and also note the temperature of that mixture by dipping the thermometer in it. Note down the brix which is the observed brix. By using the temperature correction chart from which check the temperature correction error and add it into observed brix which gives the actual brix and multiply it with dilution factor.
5.4.1.3
Observations and Calculations
Observed Brix Value
=
7.5
Temperature of Sample
=
31oC
From Temperature Correction Chart
=
0.69
Actual Brix
=
7.5+0.69
=
8.19
5.4.2
Determination of Total Sugar in Molasses
5.4.2.1
Apparatus
Beaker, Burette, Balance
5.4.2.2
Procedure
Take 4g of molasses in 250ml beaker and add 250ml distilled water. Then take 50ml of prepared solution and again dilute it in 200ml of distilled water. Then add 10ml of 6.2N HCl and heated it at 65oC for 10 minutes. Titrate the above mixture against Fehling Solution A&B and calculate the total sugar by noting the burette reading and use it in the formula. Total Sugar
=
5000× Total wt. of sample B.R
5.4.2.3
Observations and Calculations
Weight of sample
=
4g
Burette reading
=
26.9
Total Sugar
=
5000×4.0 26.9
=
46.46%
CHAPTER 06 Pre-Fermentation Section 6.1
Introduction
Pre-fermentation is a process in which Inoculum or bacteria are prepared for alcoholic fermentation. Inoculation or microorganisms are prepared by using certain chemicals (Urea, Yeast, NaF, and H3PO4) which provide environment to cells for their best growth. In this process Aerobic Fermentation takes place. The process of pre-fermentation occurs in R-405 A-D (Bub Vats) each having a capacity of 40m3.
6.2
Aerobic Fermentation
The process of fermentation which takes place in the presence of Oxygen (air) is known as Aerobic Fermentation.
6.3
Procedure of Pre-Fermentation
Bub Vats are feed from dilution tank R-312 A/B. The brix of feed given to Bub Vats is 25-29% which is further reduced to 15% by the addition process water. Nutrients such as urea, H3PO4, NaF are added to Bub Vats for better growth of microorganisms. Brix of Bub Vats is controlled at 6-7%. If controlled brix is low than 6%, yeast cells will die. Another thing which is also very important for pre-fermentation is the circulation of Bub Vats. There are basically two purposes of circulation. Better mixing of Biomass. To control temperature of Bub vats. Mixing of biomass is done to circulate microorganisms. If circulation is not done, then cells will settle down at the bottom and will reduce the fermentation efficiency. Circulation with heat exchanger is done to control the temperature of Bub Vats by exchanging heat with cooling water. If cooling is not done properly, the temperature of the Bub Vats increases, the anti-cells like wild yeast etc. formed which results increase in acidity.
6.4
Shutdown Procedure of Pre-Fermentation
After the complete procedure of pre-fermentation, transfer all the Bub Vats to the fermenters with 18-20% Bub Vat mixture in each fermenter. After complete transfer of all Bub Vats to fermenters, wash them with water and sterilize with steam.
R-312 A
R-312 B
Mash Line Urea Urea
Process Water
Process Water
Urea
Process Water
Urea
UREA
Process Water
R-405 D
R-405 C
R-405 A
R-405 B
Process flow Sheet for Bub Vats (pre-fermentation)
CHAPTER 07 Fermentation Section 7.1
Fermentation
Fermentation is a bio-chemical reaction in which organic compound is converted to alcohol in the presence of enzymes. The enzymes are microorganisms, which acts as a bio-catalyst. OR The process of conversion of starch and sugars to ethyl alcohol under the influence of yeast is called fermentation. Fermentation is an exothermic reaction and heat is evolved when reaction is taking place. The better the heat evolved, the better we can control the fermentation reaction. Heat is removed by using the heat exchangers and cooling water is used as cooling media.
7.2
Alcoholic Fermentation of Molasses
The technology of yeast fermentation of molasses is a simple and worked out essentially. The process involved dilution of molasses and inoculation with yeast fermentation.
7.3
Factors Affecting Fermentation Enzymes
The action of enzymes is greatly affected by the following factors. The temperature at which microorganism alive. The pH of the substrate. Growth of unwanted wild yeast, bacteria or germs in culture tank. To get a maximum chemical yield, it is frequently advisable to suppress additional increase in microorganisms.
7.4
Fermenters
The fermenters are the tanks where anaerobic fermentation (in the absence of Oxygen) takes place. In fermenters, we can achieve alcohol as can as possible. In Noon Sugar Mills Distillery, there are ten fermenters labeled with R-406 A-J each having capacity of 200m3.
7.4.1
Fermenter capacity
Scale of one fermenter is as follows: 1% fermenter level
=
9.95cm
1cm
=
280 liters of wash
So, 1% diluted wash
80% diluted wash
7.5
=
9.95×280 liters
=
2786 liters
=
2786×80
=
222880 liters
Chemical Equations
Sugar in the presence of enzymes converted to alcohol, carbon dioxide, and heat. Fermentations reactions take place as follows: C12H22O11 (Sucrose)
+
H2O (Water)
(Enzymes)
C6H12O6
C6H12O6 (Glucose) 2C2H5OH
+
+
C6H12O6 (Fructose)
2CO2 +
Heat
From the equations, it is observed that: C12H22O11 + H2O 12×12+1×22+16×11 342
C6H12O6 + C6H12O6 2× (6×12+1×12+16×6) 2× (180) 360
C6H12O6 12×6+1×12+16×6 180
2C2H5OH + 2CO2 + 2× (12×2+1×5+16+1) 2× (46) 92
Molecular weight of sucrose
=
342g
342g of sucrose produced alcohol
=
92g
1g of sucrose produced alcohol
=
92/342
=
0.269g of Alcohol
Heat
7.6
Chemicals Used during Fermentation
7.6.1
Yeast
Yeasts are defined as ―Unicellular microorganisms producing zymase which convert sugar into alcohol and carbon dioxide, used in inoculate the molasses for the production of alcohol and in baking. CO2 produced causes the dough to rise.‖ In alcoholic fermentation by yeasts, these microorganisms furnish an organic catalyst or enzyme which affects the hydrolysis. The yeast used in cultural tanks is Saccharomyces cerevisiae contains 150-300 million cells per cm3. The required amount of yeast should be present in each tank. Due to these cells, Alcohol is prepared. The best production depends upon the pure and healthy culture.
7.6.2
Kingdom
Fungi
Phylum
Ascomycota
Sub-Phylum
Saccharomycotina
Class
Saccharomycetes
Order
Saccharomycetales
Family
Saccharomycetaceae
Genus
Saccharomyces
Species
S.Cerevisiae
Sodium Fluoride (NaF)
It is used as a germicide in the culture tanks in which yeast is cultured. These culture tanks are Bub Vats. NaF is used because wild yeast and some other germs are harmful for yeast.
7.6.3
Phosphoric Acid (H3PO4)
The function of phosphoric acid is to separate the cells from each other and also acts as a supplement for the deficiency of phosphate in the molasses according to the requirement.
7.6.4
Urea (H2N-CO-H2N)
Urea is also added in cultural tanks i.e. Bub Vats. Microorganisms use nitrogen as feed so it is used as micro-nutrients. It is added in the form of solution which is formed by dissolving urea pellets in water. Nitrogen addition in the form of urea is also important for better DNA replication of yeast cells during budding process.
7.6.5
Calgon (Sodium hexa Meta Phosphate)
Calgon is the settling agent which is used in fermenters. By the use of Calgon, all muddy type material settles down at the bottom of the fermenter.
7.7
Substrate Preparation
Sugar (Molasses) must be diluted to suitable concentration or brix for economy of utilization into alcohol conversion.
7.8
Fermentation procedure
Fermenter setup is done by transferring 18-20% of Bub Vats to fermenters. When setup is started, the feed to fermenter is about 25-29 brix. Yeast cells consume that brix and convert sugars into alcohol. Fermenter filling is normally completed in 18 hours. After complete filling, the feed is stopped and let the reaction carry on. While reaction is taking place, the temperature of the fermenters is also controlled by cooling media i.e. showering the cooling water on fermenter, temperature remain controlled in the range of 25-35oC. After completion of fermenters filling allow completing its reaction and writing down brix and temperature on hourly basis and can be represented in graph how brix and temperature changes as reaction proceeds. When reaction is completed, yeast cells died and final alcohol is checked. Now add 8-16kg of Calgon (settling agent) in dead fermenters i.e. after the completion of reaction. Circulate the fermented wash for 1.5 hour after addition of settling tank. Give maximum time (7 hours) as settling time to each fermenter before starting its distillation. Transfer the suspended mud from bottom of each fermenter to R-407 till wash become clear. Transfer the wash for distillation to R-304 through pump P-408 A/B. Wash each fermenter with water after 2-3 cycles of setup.
Brix as a function of time 14 12 10 8 6
X-Axis
Time
4
Y-Axis
Brix
2 0 0
5
10
15
20
25
30
Temperature as a function of Time 40 35 30 25 20 15
X-Axis
Time
Y-Axis
Temp.
10 5 0 0
5
10
15
20
25
30
Graphical Representation of Brix and Temperature as a function Time
Dilution R 312 A
Dilution R 312 B
R 405 A-D Bio mass
R 406 B
R 406 C
R 406 F
R 406 E
R 406 G
R 406 H
Setup Line
Feed Line
R 406 A
R 406 D
R 406 I
Process flow Diagram of Fermenters Setup
R 406 J
7.9
How to Increase Alcohol Yield?
Alcohol yield can be increased by: Elimination of bacteria by pasteurization. Some of non-fermentable components in molasses will be converted into fermentable components by acid hydrolysis. Removal of volatile organic acid, free SO2, gums, waxes, inorganic salts. Better quality of yeast improves the ferment ability.
7.10
Shutdown procedure of Alcoholic Fermentation
The fermenters are not setup after completion of its distillation. Thorough washing of fermenter with water is strictly required.
7.11
Benefits of Fermenter Cooling
These are following benefits of fermenter cooling. Yeast and bacteria have different temperatures to quit their activities. Controlled fermentation at temperature preferably quit to optimum activity of the yeast. This results in more sugars being converted into alcohol and fewer amounts are converted to byproducts of fermentation. At lower fermenter cooling temperature, there is reduction in alcohol losses in the carbon dioxide off gas. Shorter fermentation times are achieved by controlled cooling. This results in a shorter turn around for fermenters and an increase in production of the same equipment. Good agitation by pumped recirculation ensures intimate contact between the yeast and the sugar minimum opportunity for conversion. Due to improved heat transfer characteristics of the plate heat exchanger over other form of cooling, more efficient water utilization can be achieved.
7.12
Laboratory Analysis Regarding Fermentation Section
The laboratory analysis of fermentation is most important which holds the strength and quality procedure.
7.12.1
To count the cells of fermentation in Bub Vats
Take 20ml of sample in measuring cylinder. Dilute it with water up to 100ml and mix well. Wash slide of microscope with distilled water and dry it with tissue paper. Put a drop of diluted sample on the slide with the help of glass rod and cover it with a glass sheet. Put the slide in microscope and adjust focusing to count the cells in 16 squares.
7.12.1.1
Calculations
Cell count in millions/cm3
7.12.2
=
28×4×1.25
= 140 million/cm3
Strength of Alcohol in Fermenters
Take 50ml sample in Ebulliometer Boiler. Fill water in Boiler condenser. Start heating the sample with spirit lamp after putting thermometer in boiler. When temperature of boiler becomes constant for 1-2 minutes, note down the temperature. Repeat the above procedure by taking 15ml water in boiler instead of sample to determine reference temperature ―RT‖ of water. Calculate Alcohol %age on Ebulliometer disk. Ebulliometer is used to determine the %age of Alcohol less than 10%.
7.12.2.1
Calculations
Boiling temperature of Sample
= 92.2oC
Boiling point of water (Reference temperature)
= 99.5oC
From disk the strength of Alcohol will be
=
7.12.3
7.9%
PH of Bub Vats and Fermenters
Wash the electrode with distilled water and dry it. Then take buffer solution of known pH in 100ml beaker. Dip Electrode in it and note down the reading. Again wash it and take 100ml sample in beaker and note down the reading in the same manner.
7.12.3.1
Observations
PH of Bub Vat R-401 = 4.1 PH of fermenters
7.12.4
= 4.2
Brix of Bub Vats
Brix is checked with the help of brix meter.
7.12.4.1 Time
Observations Brix of Bub Vat (R-401A)
07.00
12
08.00
11
09.00
10
10.00
08
CHAPTER 08 Distillation Section 8.1
Distillation
A process in which a liquid or vapor mixture of two or more substances is separated into its component fractions of desired purity, by the application and removal of heat is known as Distillation.
8.2
Types of Distillation
Following are the main types of distillation: Fractional Distillation Vacuum Distillation Steam Distillation
8.2.1
Fractional Distillation
A mixture of two or more components can be separated by fractional distillation when their boiling points differ by more than 40oC. The use of fractionating column has found a remarkable use in modern industry especially, in petroleum, coal tar and crude alcohol industries.
8.2.2
Vacuum Distillation
The compounds which decompose before their boiling points are distilled under reduced pressure. Due to vacuum boiling points of components becomes low and distillation is carried out at low temperatures. Vacuum distillation is an economical unit operation.
8.2.3
Steam Distillation
Steam distillation is used for those substances which are heat sensitive and more heat will rupture their structure.
8.2.3.1
Stripping Column
The part of distillation column which removes the more volatile components from a liquid feed is generally known as stripping column.
8.2.3.2
Rectifying Column
The part of distillation column which removes the less volatile components from a liquid feed is generally known as rectifying column.
8.2.3.3
Reflux
In practice for increased efficiency of separation of two components and for heat economy, it has been found necessary to return back some amount of the condensed portion of vapor to the top of the column. These returned condensed vapors are known as Reflux. It is also necessary to increase the quality of product and as well as to maintain equilibrium on plates.
8.3
DISTILLERY-I
Distillery-I was imported from France and made by the company M/S SPEICHUM. It has the capacity of making 50,000 Liters/Day. It consists of three distillation columns.
Vacuum Column D-510 Low Boiling Column D-530 Rectification Column D-540 8.3.1
Vacuum Column D-510
Fermented mash from overhead tank R-304 passes through the automatic valve FIC-510, where flow is regulated and penetrates directly into the top of stripping column of D-510. Negative pressure in D-510 lowers the boiling point of feed in this column, enabling it to be heated by the vapors coming from top of the rectification column D-540. Alcoholic Vapors at the head of D-510 are condensed in exchangers E-516, E-517. The condensate from E-516 and E-517 is collected and feed to D-530. This condensate is 50-56% Alcohol by volume.
8.3.2
Low Boiling Column D-530
Low boiling column is feed with condensate of E-516, and E-517 and spent lease of D-540 having temperature of about 110oC. The feed temperature to D-530 is between 83-86oC. This feed is diluted up to 20-25% by mixing the condensate and spent coming from bottom of D-540, where steam is provided to D-530 for separation of impurities from alcohol vapors. Volatile
vapors and impurities concentrated in upper part of the column and condensed in E-535. The condensate is collected as LOW GRADE ALCOHOL in R-650 and impurities are vent off.
8.3.3
Rectification Column D-540
Rectification column is used for rectification of bottom product of D-530 column. In rectification column, three types of products are achieved: Fusel Oils, Low Grade Alcohol and Industrial Grade Alcohol. Bottom product of D-530 column is transferred to D-540 and steam is applied, the more volatile components are collected at top. There is different temperature profile in column. At the bottom of D-540 temperature range is 100-112oC. At the middle of the column temperature range is 9799oC from where heavy oils like fusel oils are extracted. At the top of the column temperature range is 92-94oC from where rectified alcohol is obtained. The rectified alcohol has strength of 96.3% while low grade alcohol is of 90-92% strength. The fusel oils have strength of 50-56%.
8.3.3.1
Rectified Alcohol
The strength of rectified alcohol is about 96.4% having boiling point of 78 oC and known as ethyl alcohol.
8.3.3.2
Low Grade Alcohol
Low grade alcohol has strength of 94% and boiling point of 77oC. It is used in many industries like paints, varnishes, polishes, printing and pharmaceuticals.
8.3.3.3
Fusel Oils
It is mixture of high alcohols having boiling points range 90-150oC. It has unpleasant smell and used in leather industries.
C.W out
R 304 30-34C
D-512
Uncondensed Vapors
62-64C
Vapors
C.W out
Vapors
C.W out
60-70C
C.W In
Condensate
C.W in
E 517
C.W in
E 516
Vapors from D 540
Low Grade 92% Condensate tank
68-69C
67-69C
E 545
50%
80-84C
D 510
20% P 531 A/B
D-530 To spent Wash
P 516 A/B From Fermenter
R 650 A
E-535
65C
From D 540
P 408 A P 408 B
P 501 A/B/C
Process Flow Diagram of Distillery-I (D-510 & D-530)
P 541 A/B
Vapors to E 545
Uncondensable vapors R 535
94-105C
Rectified Spirit
Reflux
64-69C
Low Grade extraction FIC 549
Feed
FIC 531
Fusel oils Bottom D 530
E 545
R-545 28-32C
P 531 A
FIC 530
P 545 A/B
100-112C
P 531 B
S 540 D 540
To D 530
Spent Lease Tank 116C
R 650 R 652 A/B
P 541
Process Flow Diagram of Distillery-I (D-540)
8.4
Distillery-II
8.4.1
Introduction
The plant of distillery-II was imported from Brazil. By the use of this plant, we can prepare or distill the Absolute Alcohol which can be used as a fuel for internal combustion engines when mixed with petrol or gasoline. Its production is 30,000 Liters/Day. There are three columns in distillery-II also, but two out of them are in operation. Boiling Column(A) Rectification Column(B)
D-510 D-540
Boiling column is operating under pressure of 1.6bar that’s why this distillation is also known as pressure distillation and rectification column is producing rectified spirit.
8.4.2
Operational procedure
Water level is maintained in the boiling column. Steam is supplied to both columns A&B and water vapors are produced. These vapors are refluxed and temperature of the boiling column’s bottom is maintained at 105-106oC and for rectification column is + 104oC. The fermented wash stored in R-304 comes down by gravity and passes through flow meter FI. By pump it is send to overhead heater E. Now wash passes through heat exchangers K, K1, K2 in which from one side wash passes and from other side hot effluent passes. So temperature of wash again increases. By pump it is then fed from upper side of column and steam is supplied from bottom. Alcoholic vapors produced in boiling column (A) pass through the condenser R. Maximum vapors are condensed here but some remains uncondensed. These uncondensed vapors then passed to the next condenser R-1 and all vapors are condensed. Cooling water is used as cooling media. Composition of alcohol with impurities is different on every plate due to different boiling points. Condensed vapors of R & R-1 are then collected in header from where this condensate is fed to rectification column D-540 and steam is also supplied. The vapors produced in rectification column are then passed through condenser E where vapors are condensed but some remain uncondensed. These uncondensed vapors are then passed through another condenser E-1 here also some vapors still remains uncondensed which finally condensed in E-2 and reflux back to D-540. Rectified spirit is taken from top two plates of the column and stored in daily receiver storage tank R-652 C/D.
40—45 c
60—70 c
Condenser E
Uncondense Vapors
Condenser R
Vapors
C.W out
R 304 Wash
P 408 A
C.W in
C.W out
Condensate
P 408 B 35—40 c
C.W in
Condenser R1
Fermenter Wash from R--304
104 c
Reflux Feed to D-510
Low Grade Alcohol
Spent Wash To Spent Wash Pits
105-106 c
D 510
Steam
Steam
P-511 A
H.E K
H.E K1
P-511 B
Process Flow Diagram of Distillery-II (D-510)
H.E K2
Uncondensed Vapors
Condenser -E
C.W out 26-30 c
Condensate
Condenser -E2
40—45 c
Condenser Tank
C.W in
Reflux
C.W in
Vapor from D--510
92—97 c
Condenser -E1
C.W out
Uncondensed Vapors
Mash
60-70 c
Mash out
Condensate
Low Grade Alcohol 102—106 c
Fusel Oil S 540
D--540 Rectified
E-4
E –540 28—32 c
Fic-549
R—652 C/D
Process Flow Diagram of Distillery-II (D-540)
8.5
Laboratory Analysis Regarding Distillation Section
8.5.1
To check the strength the Rectified Alcohol
8.5.1.1
Apparatus:
Alco-meter Thermometer Cylinder Alcohol Strength Notebook
8.5.1.2
Procedure
Take the sample in 250ml measuring cylinder. Dip the Alco-meter and Thermometer in it. When the Alco-meter adjusts itself in sample, note down the reading from the meter and also note the temperature. Then note the strength of sample from alcohol strength book in which different strength readings are given with temperature.
8.5.1.3
Observations
Temperature of sample taken
=
28oC
Alco-meter Reading
=
+98.4
Strength of sample
=
96.4%
8.5.2
Time test KMnO4 for final product
8.5.2.1
Apparatus
(from alcohol strength book)
Test table Beakers Thermometer Pipette
8.5.2.2
Procedure
Take 10ml sample in test tube and keep that temperature 24oC. Add 5ml of KMnO4 in test tube. The light pink color is appeared. Note the time till color changes from light pink to yellow.
8.5.2.3
Observations
Time for rectified sample
=
16.5min
This result shows that sample contain low %age of impurities.
8.6
Molecular Sieve Dehydration Plant
The factors used to establish the design basis for the vapor phase molecular sieve based dehydration system for fuel grade ethanol as follows: Anhydrous Alcohol Production Capacity Product quality Feed Stock Feed Stock Quality (Ethanol)
8.6.1
= = = =
100,000 liters/day 99.99% Rectified Spirit 95%
Process Description
From feed tank, rectified spirit is pumped into the column are condensed in condenser and sent back to column as reflux. Rest of vapors is passed through super heater and is taken into molecular sieve unit for dehydration. The vapors pass through a bed of molecular sieve beds and the water/moisture in the feed vapors is absorbed by the molecular sieve material and anhydrous ethanol vapors exit from the molecular sieve unit. Hot Anhydrous Ethanol is then further cooled down in the product cooler to bring it close to the ambient temperature. The water leaves from the bottom of the column and contains only traces of alcohol.
8.6.2
Advantages of System
Minimum Labor Stable Operation Near theoretical recovery Steam consumption minimized by multi-stage preheating to permit substantial heat recovery and reuse. An advance control system, developed through years of experience to provide sustained, stable, and automatic operation. Product quality maintained.
CHAPTER 09 Effluent Treatment Plant (ETP) 9.1
Introduction
This informative good practice guide deals with improving the performance of ETP to reduce operating costs and reduce environmental pollution. Most companies operate effluent treatment plants to reduce the potential for pollution. Effective management and control of the processes used for effluent treatment will help you to: Reduce your operating costs and thus increase profits. Achieve more effective compliance with legislation. Improve yours company Image. For that purpose Noon Sugar Mills Distillery operates a Bio-gas Plant. This plant was installed in 1998.
9.2
Bio-Gas Plant
The spent wash of Distillery Section is acidic in nature with pH of 3.5-4.00 and temperature 7080oC. It is very dangerous and harmful for both terrestrial and aquatic life because of its high BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand). If it is directly drained to Canal, River etc. it causes environmental pollution and it also be the cause of death of aquatic animals because it reduces the amount of Oxygen in water due to which animals die. To overcome or reduce this type of environmental pollution, NSM operates a bio-gas plant which not only minimizes their pollution problem but reduces their fuel problem up to 70%.
9.2.1
BOD (Biological Oxygen Demand)
It is the oxygen requirement of polluted water to decompose the biological impurities. It is the amount of dissolved oxygen used by microorganisms in the biochemical oxidation of organic matter during a five day period. According to National Environmental Quality Standards (NEQS) its amount should be 250-350ppm but the effluent has 45,000-50,000ppm which reduces to 500-1000ppm by diluted it with saline water after producing gas from it, which is still beyond NEQS.
9.2.2
COD (Chemical Oxygen Demand)
The COD represents the water pollution due to various chemical compounds and organic matter. It is the amount of dissolved oxygen required by biochemical oxidation of chemical compound and organic matter to decompose it into less harmful compounds. This value is usually greater than BOD. According to NEQS its amount should be 300-400ppm but the effluent has 100,000-
110,000ppm which reduces to 2500-4000ppm by diluted it with saline water after producing gas from it, which is still beyond NEQS.
9.3
Procedure
Effluent from Distillery Section is collected in Pits from where it is fed to the digesters. There are three digesters for these purpose each having a capacity of 12,000tons. First of all, cow dung in the form of slurry is introduced to digesters which act as an inoculum media for the effluent. Then about 350m3 of effluent is fed to each digester per day. The pH inside the digesters is maintained up to 7.2-8.00. Anaerobic fermentation takes place and as a result bio-gas is produced which serves as a fuel for industry and minimizes energy crises for industry. Approximately 28,000-30,000m3/day, bio-gas is produced from all of these three digesters. Digesters are covered with polymeric membrane which avoids the entering of air in digesters. When gas is produced the membrane also lifts up due to the pressure of gas. This gas contains about 50-60% Methane, 20-30% Carbon dioxide, and small amounts of Nitrogen, Carbon monoxide and hydrogen sulfide.
9.4
Usage of Produced Bio-gas
Bio-gas produced from effluent is then use as a fuel for the production of steam in boilers. There are two fire tube boilers with capacities 10ton and 12 ton respectively. Bio-gas with Sui-gas is burnt in the boiler to produce steam. About 70% bio-gas and 30% Sui-gas (Mixture) is used in boilers. Saturated steam is produced in these boilers with pressure of 110psi. This steam is used in Distillery Section. So, this is a cyclic process means the effluent from Distillery is collected from which Bio-gas is produced which is used in the production of steam used in Distillery. If bio-gas is not used in industry i.e. when industry is not in running condition, it is burnt into autoflame to avoid the atmospheric pollution.
