Fermentation & Distillation

2008

Er. Raghvendra SachanRVS

1/1/2008

Raghvendra Sachan 2

2008

Er. Raghvendra SachanRVS

1/1/2008

Fermentation & Distillation

CONTENTS

1. ALCOHOLIC BEVERAGES:......................................................................- 3 -

i) DISTILLED LIQUORS:.................................................................................................- 4 -

2. MANUFACTURE OF ALCOHOL................................................................................- 5 -

i) RAW MATERIAL FOR ALCOHOL INDUSTRY:......................................................- 5 -

ii) ALCOHOL YIELD.........................................................................................................- 6 -

iii) PRODUCTION OF ETHANOL BY FERMENTATION OF SUGAR:........................- 7 -

iv) BY PRODUCTS OF ALCOHOL MANUFACTURE....................................................- 8 -

3. FERMENTATION..........................................................................................................- 9 -

i) ALCOHOLIC FERMENTATION.................................................................................- 9 -

4. DISTILLERY................................................................................................................- 11 -

5. DISTILLATION...........................................................................................................- 12 -

i) PROCESS DESCRIPTION..........................................................................................- 12 -

6. EFFLUENT TREATMENT PLANT............................................................................- 13 -

i) CALCULATION OF COD...........................................................................................- 16 -

ii) ENVIRONMENTAL SIGNIFICANCE OF DO..........................................................- 17 -

iii) BIOCHEMICAL OXYGEN DEMAND......................................................................- 17 -

7. EXPERIMENTAL DETAILS......................................................................................- 18 -

8. BOTTLING UNIT........................................................................................................- 20 -

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INTRODUCATION

An alcoholic beverage is a drink containing ethanol.

Ethanol is a drug, and depressant, and even though alcohol is a legal drug in most parts of

the world, many societies regulate or restrict the sale and use of it.

Ethanol (CH3CH2OH), the active ingredient in alcoholic

beverages, is almost always produced by fermentation - the metabolism of carbohydrates

by certain species of yeast in the absence of oxygen. The process of culturing yeast under

alcohol-producing conditions is referred to as brewing. Spirits are produced by

distillation of a fermented product, concentrating the alcohol and eliminating some of the

by-products.

Alcoholic beverages include low-alcohol-content beverages

produced by fermentation of sugar- or starch-containing products, and high-alcohol-

content beverages produced by distillation of the low-alcohol-content beverages.

Sometimes, the alcohol content of low-alcohol-content beverages is increased by adding

distilled products, particularly in the case of wines.

Most yeast cannot grow when the concentration of alcohol

is higher than about 18% by volume, so that is a practical limit for the strength of

fermented beverages such as wine, beer, and sake. Strains of yeast have been developed

that can survive in solutions of up to 25% alcohol by volume, but these were bred for

ethanol fuel production, not beverage production. Spirits are produced by distillation of a

fermented product, concentrating the alcohol and eliminating some of the by-products.

In many countries, alcoholic beverages are commonly

consumed at the major daily meals (lunch and dinner). Most early beers were in fact

highly nutritional and served as a means of calorie distribution

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ALCOHOLIC BEVERAGES:

Alcoholic beverages vary considerably in their ethanol

content and in the foodstuffs from which they are produced. Most alcoholic beverages

can be broadly classified as fermented beverages, beverages made by the action of yeast

on sugary foodstuffs, or as distilled beverages, beverages whose preparation involves

concentrating the ethanol in fermented beverages by distillation. The ethanol content of a

beverage is usually measured in terms of the volume fraction of ethanol in the beverage,

expressed either as a percentage or in alcoholic proof units.

Undistilled Beverages :

These are produced by fermentation process from fruit juice or

grains. The beverages prepared from grape juice are called wines. Wines contain 18-20%

alcohol and produced by natural fermentation are called “Natural wines”. Weak natural

wines are made stronger by addition of pure alcohol from outside and are named as

Fortified wines. e.g. beer, champaigne.

Distilled Beverages :

If the fermented liquids are distilled, most of the alcohol along

with other volatile products like flavor, essential oils, esters and higher alcohol pass over

as distillate. The distiller liquors have a high alcohol content that may go up to 50% or

more. e.g. whisky, brandy, rum, gin etc.

It implies that pure brandy, whisky will be made strictly

from their raw materials, which are cherries, malt respectively. But in the case of

blended, some part of alcohol is supplied by genuine raw material while the rest is

supplied through the spirit manufactured. While in the case of essence, only the essence

of brandy or whisky is mixed in rectified spirit. This is usually cheap and low in quality.

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DISTILLED LIQUORS:

COUNTRY LIQUOR: - Single distilled spirit

FOREIGN LIQUOR: - Double distilled spirit

COUNTRY LIQUOR is of two types

a) Plane country liquor:

It is produced by mixing alcohol (80-90%) strengthened

with DM water on a volume basis such that final strength of alcohol is 25%.

b) Spice (masala) country liquor:

It is made by mixing alcohol with water such that alcohol is

around 42.8%. Along with this, malt essence and caramel, which gives it the unique

brownish color, is also added.

FOREIGN LIQUOR is of following types:

Whisky :

Made from malt spirit (malt is the technical name of germinated and dried

barley), has 40-50% alcohol.

Brandy :

Made from grapes, litchis, cherries, apple has 40-50%alcohol.

Rum :

Made from molasses spirit has 45-55% alcohol.

Gin :

Made from maize, barley has 40-45% alcohol.

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MANUFACTURE OF ALCOHOL

In Mohan Meakin Ltd. the bulk of alcohol is being

produced from sugar cane molasses. Molasses is a thick viscous bye-product of the sugar

industry which is acidic in nature, rich in salts, dark brown in colour and it also contains

sugar which could not be crystallized. For manufacturing alcohol, the Molasses is diluted

with water into a solution containing 15-16 % of sugars. This solution is then inoculated

with yeast strain and is allowed to ferment at room temperature. The fermented wash is

distilled in a series of distillation columns to obtain alcohol of adequate/ requisite

strength and quality/ specification. This alcohol is used for various purposes including

potable and industrial. For manufacture of alcoholic beverages, the alcohol is, if

required, matured and blended with malt alcohol (for manufacture of whisky) and diluted

to requisite strength to obtain the desired type of liquor/ Indian Made Foreign Liquor

(IMFL). This is bottled in bottles of various sizes for the convenience of consumers.

RAW MATERIAL FOR ALCOHOL INDUSTRY :

In alcohol fermentation, glucose or sugar cane is the

fermentation materials. Therefore any natural product which contain this sugar can be

easily transformed into them, is a potential source of ethyl alcohol.

The raw material for alcohol industries are:

stuff containing fermentable sugars:

e.g. Sugarcane juice, dry date molasses, fruit juice etc.

Material containing starch or cellulose:

e.g. potato, Rice, barley, maize or wood

They are first treated to convert the starch or cellulose into the sugar’s that are then

fermented by yeast.

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ALCOHOL YIELD

If spirit=X (bulk liters) and it has Y% of alcohol in it then

ALCOHOL YIELD = (XY)/100

BASIS

For the manufacture of 1000 liters of 94.5% ethyl alcohol

Molasses 5000 g

Water 20000 lit

Yeast 2.5 kg

Sulphuric acid 0.125 lit

Urea 0.25 kg

Coal 500 kg

Plant capacity 20000 lit/day

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PRODUCTION OF ETHANOL BY FERMENTATION OF SUGAR :

Ethyl alcohol is produced from sugar-containing material

such as molasses by fermentation process utilizing yeast enzymes to convert the sugar

into alcohol. alcoholic fermentation is the conversion of sugar into carbon dioxide gas

(CO2) and ethyl alcohol. This process is carried out by yeast enzymes. This is in fact a

complex series of conversions that bring about the conversion of sugar to CO2 and

alcohol

The most widely used molasses is obtained as a by product

in the sugar mill and contain glucose and fructose.

CHEMICAL REACTIONS:

C12H22O11 + H2O 2C6H12O6

C6H12O6 2C2H5OH + 2CO2

Side reaction

2C6H12O6 + H2O ROH + RCHO

(High mol. wt.)

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invertase

invertase

BY PRODUCTS OF ALCOHOL MANUFACTURE

i) Carbon-dioxide : large quantities are evolved during the fermentation process. This is

used in the solid form as ice.

ii) Fused oil : is a liquid with nauseating odour. It is used in confectionary and fruit

essences.

iii) Acetaldehyde : obtained during the alcohol distillation

iv) Spent wash : the residual liquor from which ethyl alcohol has been removed by

distillation. It contains nitrogenous matter which can be used as manure and fodder.

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FERMENTATION

It involves slow decomposition of big molecules of certain

organic compounds into simpler ones under the catalytic influence of non living complex

substances called ferments. The majority of process requires oxygen and is classified as

aerobic. A few processes carried out in the absence of oxygen are called anaerobic.

Fermentation is in two parts.

Part 1

Aerobic (Oxygen is present)

This is the initial rapid process where the yeast is doubling its colony size every 4 hours.

(Usually 24-48 hours)

Part 2

Anaerobic. (No oxygen present)

Slower activity and the yeast focus on converting sugar to alcohol rather that

increasing the number of yeast cells.

ALCOHOLIC FERMENTATION :

The chief ethanol producers are fungi especially strain of

Saccharomyces cerevisiae. The yeast respires aerobically but in the absence of air they

ferment carbohydrates to ethanol and CO2. The by-product, CO2, bubbles through the

liquid and dissipates into the air. The other by-product alcohol, remains in the liquid

which is great for us but not for the yeast, as the yeast dies when the alcohol exceeds its

tolerance level. 

The fermentation process has other limits such as

temperature. Greater than 27C kills the yeast less and than 15C results in yeast activity

which is too slow.

The conversion of glucose to ethanol can be represented as:

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C6H12O6 2CO2 + 2C2H5OH

The ability of yeast cells to convert sugar into Carbon

dioxide and Alcohol is down to enzymes. Several enzymes are involved each does its

step in the process. The final step is Zymase reduction which takes the end product of the

other enzymes (acetaldehyde/glycerol), and turns this into good old ethyl alcohol. Sadly

alcohol actually destroys enzymes and kills the yeast cell if in high concentrations. This

happens at different levels for different strains of yeast.. Brewers yeast cannot withstand

much beyond 5 or 6% Alcohol by volume. Wine yeast is more tolerant at a range of 10-

15%. Specially cultured strains of yeast with the correct environment can withstand

alcohol levels up to 21% alcohol.

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DISTILLERY

THERE ARE TWO TYPES OF DISTILLERISES:

1) Potable is prepared from raw material containing sugar. Firstly the alcohol is produced

from raw material and then liquor is prepared from alcohol.

2) Non potable alcohol is manufactured in the form of spirit.

The distillery industry today consists broadly of two parts,

one potable liquor and the industrial alcohol. The potable distillery producing Indian

Made Foreign Liquor and Country Liquor has a steady but limited demand with a growth

rate of about 8 per cent per annum. The industrial alcohol industry, on the other hand, is

showing a declining trend because of high price of Molasses which is invariantly used as

substrate for production of alcohol. The alcohol produced is now being utilized in the

ratio of approximately 52 per cent for potable and the balance 48 percent for industrial

use. Over the years the potable liquor industry has shown remarkable results in the

production of quality spirits.

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DISTILLATION

Distillation is the process of separation of two miscible

volatile liquids by vaporization, given that both the liquids exist in both the phases.

Distillation of raw alcoholic brews concentrates the alcohol and leaves behind many

chemicals that are not volatile at distillation temperatures

In practices distillation can be carried out by either of two

principle methods. The liquid mixture to be separated and condensing the vapor without

allowing any liquid to return to the still, and then there be no reflux.

The second method is based on the return of the part of the

condense to the still under such conditioned that this returning liquid is brought into the

condenser. Either of these methods can be conducted as a continuous or batch process.

Distillation unit consist of an analyzer (23 plates), aldehyde column and rectifier (56

plates).

The analyzer and the rectifier are connected via the 13 th

plate called the adjust plate. In the rectifier section the heat is provided from the bottom

to the condenser heat exchange takes place between the vapors entering the water flowing

through condenser.

PROCESS DESCRIPTION :

In it the condensed liquid from the rectifier enters the

purification column. The steam is added to the condensed liquid and the alcohol rich

vapor is sent to the condenser that is further processed to the silent column. The silent

spirit produced from the silent column is also called E.N.A. or extra neutral alcohol,

which is double distilled alcohol generally used for making whisky.

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EFFLUENT TREATMENT PLANT

The main raw material of distillery molasses and when it is

distilled after fermentation to get alcohol, produce large quantity of liquid effluent called

“spent wash”. This spent wash contains organic matter in the effluent is therefore

required to be remove so that it can be discharged safely into the environment.

In the effluent treatment plant, set up by Mohan Meakin

ltd in March 1988, the treatment of the effluent takes place in the following steps:

1. Anaerobic treatment i.e., biogas generation, two stage

2. Aerobic treatment i.e., secondary treatment

3. Clarification unit with chemical treatment

4. Second stage aeration unit with chemical treatment

5. Sludge decanter machine

6. Clarification by two methane separator clarifier

7. Ferti irrigation in the zeal of zero discharge

8. Fountain with atomization technique

9. Flocculation unit with R.C.C. clarifier for chemical treatment

10. Recycling of treated trade effluent for cooling purpose

Spent wash rich in organic matter from the distillery having

a temperature of 100-1020C, is cooled through heat exchangers to bring the required

temperature of 400C. This effluent is fed into METHANE REACTOR. Methane reactor

is the heart of effluent treatment plant. The biological process which includes the

degradation of higher organic compounds and reduction of BOD take place in this zone.

The methane (8, 000-9,000 NM 3/day) is recovered as a by product during the course of

BOD reduction. The methane reactor has been designed for 90% reduction in BOD.

The overflow of the methane digester is sent to the

anaerobic filter clarifiers and then to aeration basin having 3 surface aerators of 50 HP

each, to provide sufficient oxygen for the growth of aerobic bacteria responsible for

further decomposition of pollutants. The effluent of the brewery directly comes to

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aeration basin along with the anaerobic stream. This basin has been designed for 90%

reduction in BOD.

Effluent is then sent to clarifier where the sludge is

separated and dewatered through sludge decanter machine previously, sludge was been

dried by press deg dewatering machine and sludge drying beds. A part of sludge as

required is recirculated to the aeration basin. Separated sludge is used as manure in the

lawns and agricultural farms. The overflow effluent from the secondary clarifier is further

taken to the secondary stage aeration unit and clarifiers for further reduction of the BOD

value.

In this, chemical treatment is also added for the further

reduction in BOD value. The supernatant treatment trade effluent coming out from

methane separator clarifiers is partially sent to the fountain having an atomization

technique fro more natural aeration and it is used for ferti irrigation partially.

The F.L.D. and brewery bottle washing water of low BOD

value is mixed in second stage aeration for treatment with the help of chemicals, i.e.,

flocculants and polyelectrolyte.

The treated trade effluent thus coming out from the

clarifiers or flocculation unit is taken into the cooling tower and used for cooling purpose

in distillery condenser before being discharged. Ultimately treated effluent being

discharged top river Gomti is within the norms (i.e., 30pm) values led down by the

pollution control board.

Not only this, Mohan Meakins has a substantial saving of

coal in the form of biogas and reduced the coal consumption which is in the tune of 85-

90%.

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C.O.D. mg/L B.O.D mg/L T.S.S. mg/L FlowSpent wash 60000-65000 25000-30000 4000-5000 300-350M3/D

1. New Digester 21000-22000 3500-4000 11000-120002. Old Digester Clarifier 16000-17000 2000-2500 1500-20003. Aeration Tank no. 1 13000-5000 600-700 2500-3000 4. Degassing Tank ..... ….. ….. ….. ….. …..5. Secondary Clarifier 8000-10000 150-200 1200-1500 150-200M3/D6. Aeration Tank no. 2 3000-4000 100-150 120-1507. M.S. clarifier 7(a)-7(b) ….. ….. ….. ….. ….. …..8. Atomization Tank ….. ….. ….. ….. ….. …..9. Chemical Tank ….. ….. ….. ….. ….. ….. 250-300M3/D10. Final Clarifier 300-350 50-55 100-12011. Cooling Tower ….. ….. ….. ….. ….. …..12. Discharge Point 200-250 30 60-90 800-900M3/D13. Sludge Centrifuges & Sludge Beds….. ….. ….. ….. …..14. Gas Holder ….. ….. ….. ….. ….. …..15. Gas boiler ….. ….. ….. ….. ….. …..

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Vat Washing, Distillery & Vat washing brewery

Spent Wash

13

P.H.E

891012 11

Air Compressor

Digester 2

34 5

61

7(a) 7(b)

15 14

Anaerobic treatment i.e. two stage followed by Clarifier Secondary treatment i.e. two stages

Tertiary treatment i.e. chemical treatment

P.I Diagram of E.T. Plant

Mohan Meakin Ltd. Lucknow

Bottle Washing of I.M.F.LBottle Washing of Country Liquor

Bottling

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CALCULATION OF COD

FOUR SAMPLES FROM THE DIFFERENT STAGES OF E.T.P ARE TO BE TAKEN:

0.25ml of spent wash , make volume up to 50 ml with DM water and transfer to the

conical flask, added 75ml conc. Sulphuric acid, transferred the contents to the condenser

heat exchanger for about 2-6 hours and after that 150ml DM water added followed by

cooling for about an hour.

0.5ml from digester P1, make volume to 50ml with DM water and transfer to the conical

flask, added 75ml conc. Sulphuric acid, transferred the contents to the condenser heat

exchanger for about 2-6 hours and after that 150ml DM water added followed by cooling

for about an hour.

0.5ml from digester outlet, make volume to 50ml with DM water and transfer to the

conical flask, added 75ml conc. Sulphuric acid, transferred the contents to the condenser

heat exchanger for about 2-6 hours and after that 150ml DM water added followed by

cooling for about an hour.

1ml from aeration tank, make volume to 50 ml with DM water and transfer to the conical

flask, added 75ml conc. Sulphuric acid, transferred the contents to the condenser heat

exchanger for about 2-6 hours and after that 150ml DM water added followed by cooling

for about an hour.

Titrate all the 4 samples against ferrous ammonium sulphate with ferroin as an indicator.

COD =

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8000(Blank titration – Sample titration) * Normality of Ferrous ammonium sulphate

ml Sample

18

ENVIRONMENTAL SIGNIFICANCE OF DO

In liquid waste, DO is the factor that determine weather the

biological change are brought by anaerobic organism. It is used for oxidation of organic

and inorganic matter and produces innoculus end product.

CALCULATING DO

COLLECTION OF SAMPLE - entry of air should be avoided.

STANDARED REAGENTS FOR MEASURING DO-

Reducing agent used is 0.025N sodium thiosulphate.

Starch solution determines end point.

Standard reagent used is iodine.

End point-blue turns colorless.

BIOCHEMICAL OXYGEN DEMAND

Amount of oxygen required by bacteria while stabilizing

decomposable organic matter under aerobic condition. BOD test is used to determine the

pollutional strength of domestic and industrial waste in terms of oxygen that will require

if discharged into natural water.

How to find BOD

Adjust the sample to about 200c and aerate with diffused air to increase or decrease the

dissolved gas content of the sample to near saturation.

2 or more BOD bottles are then filled with the samples, at least one is analyzed for DO

immediately and then other one incubated for 5 days at 200C

After 5 days the amount of DO remaining in the incubated samples is determined and the

5 days BOD is calculated by subtracting 5 days results for those on day 0.

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EXPERIMENTAL DETAILS

Sugar testing:

In sugar testing two things are find out:

1) Brix :

It is the percentage of molasses solution in water by weight. Normally

available molasses has a brix is briolette. it consists of two parts, the upper part is

used to find brix, the bottom part gives the temperature, which is thus used to find

the correction to brix.

100gm molasses

900ml water

Mix

Check brix

Check the temperature

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2) Total reducing sugar (TRS)

100gm molasses

900ml water

Mix

Check brix

Check the temperature

Take 10ml solution in a pipette

Add HCl (2ml)

Boil to 70oC

Cool

Add sodium bicarbonate (neutralizer)

Titrate against fehling solution with methyl blue as indicator

Noted the reading

Formula for calculating the glucose in 100gm molasses:

Glucose in 100gm molasses

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=Fehling factor * 100*100

Burette reading

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BOTTLING UNIT

The rectified spirit that is obtained from the distillation

plant is stored in the storage tank and taken out according to the demand. The flavor

and essence are according the product nature. At the time of bottling strength

decreases to 42.8 % then after labeling they are packed and delivered.

Rectified spirit

Addition of essence and flavor

Filtration

Filling in the bottle capping

Sealing

Checking any particle impurity

Labeling security hologram

Packaging in cartons

Transportation unit

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