The document outlines the industrial production of ethanol, highlighting its uses as an antiseptic, solvent, fuel, and food additive derived from renewable sources. It details the fermentation process involving microorganisms like yeast and bacteria, the types of substrates used, and the necessary conditions for efficient production. The document also explains the recovery and purification methods required to obtain high concentrations of ethanol, including distillation and dehydration techniques.

1. Industrial production of
Industrial production of
Industrial production of
chemicals : Alcohol (ethanol)
chemicals : Alcohol (ethanol)
chemicals : Alcohol (ethanol)

2. Introduction
Why do we need ethanol?
Ethanol fermentation
Substrates for ethanol production
Microorganisms involved
process of ethanol production
fermentation conditions
Recovery
References
Contents :
Contents :
Contents :

3. Ethanol is a volatile, flammable, colourless liquid wth a slight
chemical odor.
It is used as an antiseptic, a solvent and a fuel.
Produced from reneable sources like starch & renewable
wastes.
Introduction :
Introduction :
Introduction :

4. Why do we need ethanol :
Why do we need ethanol :
Why do we need ethanol :
BIOFUELS INGREDIENTS EFFECTIVE
SOLVENT
FOOD ADDITIVES ASTRINGENT DISTILLERS GRAINS
It can be blended
with gasoline &
used in motor vehicles.
Principle ingredients
in alcoholic beverages
like beer,wine
or brandy.
Mixes easily with
water & many
organic compounds.
Ethanol can help evenly
distribute food colorings
as well as it enhances the
flavour of food extracts.
Acts as an astringent
to help clean skin,in
lotions as PRESERVATIVE
and used in other phar-
rmaceutical products.
By product of etha-
nol production which
can be fed to
livestock either wet
or dried.
E T H A N O L

5. A biological process in which sugars such as glucose, fructose &
sucrose are converted into cellular energy and thereby produces
ethanol and CO as metabolic waste products.
It is an anaerobic process.
Performed by microbes such as yeast and bacteria.
The type of the organism chosen mostly depends on the nature of
the substrate used.
Among the yeast 𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴 𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦 is the most
commonly used while among the bacteria 𝘡𝘺𝘮𝘰𝘮𝘰𝘯𝘢𝘴 𝘮𝘰𝘣𝘪𝘭𝘪𝘴
the most frequently employed for ethanol production.
Ethanol fermentation :
Ethanol fermentation :
Ethanol fermentation :
2

6. Substrates for ethanol production :
Substrates for ethanol production :
Substrates for ethanol production :
The substrates are chosen based on the regional availability
and economical efficiency.
Categories of substrates are :
SUGAR
CONTAINING
MATERIALS
STARCH
MATERIALS
LIGNOCELLULOSIC
AND CELLULOSIC
MATERIALS
Sugarcane
Sugar beet
Sugar sorghum
Corn
Other starchy
material (sweet
potato,wheat etc)
Maize silage
Barley hull
Paper sludge
Wood etc.

7. Microorganisms such as yeast and bacteria play an
essential role in ethanol production by fermenting a wide
range of sugars to ethanol.
These microorganisms provide the enzymes needed to
catalyze the reaction.
some properties of microorganisms used in fermentation:
Microorganisms involved :
Microorganisms involved :
Microorganisms involved :
𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴
𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴
𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦
𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦
𝘡𝘺𝘮𝘰𝘮𝘰𝘯𝘢𝘴
𝘡𝘺𝘮𝘰𝘮𝘰𝘯𝘢𝘴
𝘮𝘰𝘣𝘪𝘭𝘪𝘴
𝘮𝘰𝘣𝘪𝘭𝘪𝘴
has no amylases
specific growth rate of 0.13
high specific growth
rate(0.27)

8. Can tolerate high concentration of
either.
Ethanol production is coupled
with yeast cell growth.
by-products like glycerol, organic
acids are also produced.
High ethanol tolerance up to 130g/l
A broad pH range for production
(pH 3.5-7.5)
Leading to Higher ethanol
productivity.
Some properties of microorganisms used in fermentation continued :
𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴
𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴
𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦
𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦
𝘡𝘺𝘮𝘰𝘮𝘰𝘯𝘢𝘴
𝘡𝘺𝘮𝘰𝘮𝘰𝘯𝘢𝘴
𝘮𝘰𝘣𝘪𝘭𝘪𝘴
𝘮𝘰𝘣𝘪𝘭𝘪𝘴

9. Process of ethanol production :
Process of ethanol production :
Process of ethanol production :
The process is carried out in a fermenters/bioreacters.
there are five basic steps for ethanol production.These are :
1. Pretreatment of raw materials
Depends on the chemical composition of the raw material/substrates
sugary raw material require mild or no pretreatment.
cellulosic and lignocellulosic materials need extensive pretreatment.
involves Liquefaction and Saccharification
2. Preparation of nutrient solution (media)
Media composition must contains specific nutrients such as trace
elements, vitamins, nitrogen, phosphorus, growth regulators etc.

10. Process contd......
Process contd......
Process contd......
Fermentation performance of the microbes highly depends on the
composition of media.
thermotolerant vitamins (inositol,pentothenic acid, biotin) are
required to obtain rapid fermentation & high ethanol levels.
3. Preparation of inoculum
INOCULUM : A small amount of substance containing bacteria
or any other microorganisms from a pure culture which is used to
start a new culture.
the desired organism is isolated & organism are first cultured in
flasks under aerobic condition to increase the size of the inoculum.

11. 4. Fermentation process/ conditions
For the production of ethanol to occur properly following conditions
should be maintained :
Carbon source
Sugar concentration 10-18%
high concentration affects the
growth of yeast while low conc.
makes the process uneconomical.
continuous diluters are used to
get the appropriate
concentration.
Nitrogen source
Both organic & inorganic Nitrogen
source are used.
mainly ammonium sulphate (0.15 gm/
2.5 gallons of molasses) is used.
the level of nitrogen is limited.
excess promotes yeast growth &
inhibit fermentation.

12. pH
4.5-5
Temperature
20-25°C higher temperature.
favours the growth of bacteria &
also causes loss of ethyl alcohol
due to evaporation.
Time
30-72 (hours) 2-3 days.
Growth factors
Not necessary since the raw
materials used satisfy the
requirements or the culture.
Yield
On a avarage 0.4 gallons of ethyl
alcohol is obtained from 1 gallon of
molasses about 90% carbohydrates is
converted into alcohol.
Aeration
It is initially required for good
growth of the organism.
later anaerobic conditions are
created by withdrawal of oxygen
coupled with production of carbon
dioxide.

13. Aerobic
Aerobic
environment
environment
Growth rate
Anaerobic
Anaerobic
environment
environment
Slow growth
rate
Sterilized pipe
Bioreacter 1
Bioreacter 2
(seeding tank)
(fermentation tank)
STEAM STERILIZED
Batch fermentation
Continuous fermentation
Biomass production
Biomass production
Ethanol production
Ethanol production
Fig.
Biomass
production
&
ethanol
production.

14. Ethanol from fermentation broth can be recovered by
successive distillations. However, simple distillation in not
enough to get ethanol of higher concentrations.
Rectification is an application of distillation process only
which yields 95% ethanol.
For a concentration above 95%, special techniques have to be
adopted.
5. Recovery
5. Recovery
5. Recovery

15. The fermented mash is pumped into the continuous flow multi-
column distillation system where the solids and slurry mass is
separated leaving the solution of alcohol and water.
The concentration of alcohol in the liquid mixture is around 12-
15% (which means you have 85-88% water in your solution).
Since ethanol is not sufficiently separated from the impurities, it
is needed to further purify it.
Whereas, the residue mash, called stillage, is transferred from the
base of the column to the co-product processing area.
Decantation is done to obtain liquid free solids. They are dried
and used for cattle feed and fertilizers..
Distillation :

16. The 95% ethanol and 5% water obtained after rectification forms an azeotropic mixture, i.e.
after getting mixed at this particular concentration, the boiling point of ethanol and water is
same now, i.e. 78.1°C. [Ethanol's B.P. is 78.3°C and Water's B.P. is 100°C).
This is because they both have OH functional groups that are attracted to each other and
strongly bound to form an azeotrope together (An azeotropic mixture is a mixture of liquids
that has a constant/same boiling point
because the vapour has the same composition as the liquid mixture).
Azeotropic mixtures cannot be separated by simple distillation/rectification process.
Therefore, for preparation of absolute (100%) alcohol, a third component, benzene or
cyclohexane, is added to the mixture of ethanol and water. The addition of benzene will
break this azeotropic mixture and so its boiling point.
Now, the boiling point of ethanol increases and boiling point of water and benzene
decreases.
This mixture is then distilled by gradually increasing the temperature.
The ethanol gets collected at the bottom of the column (100%) whereas, water and benzene
mixture moves out of the column from the top.
Rectification :
Rectification :
Rectification :
(A). using an azeotropic mixture (to obtain 100% ethanol) :
(A). using an azeotropic mixture (to obtain 100% ethanol) :

17. (B). dehydration (to obtain 100%ethanol) :
(B). dehydration (to obtain 100%ethanol) :
Another method to remove all the water from ethanol is
dehydration.
A molecular sieve composed of crystalline zeolite is used.
The zeolite absorbs the water into it, but the ethanol will not go
into the zeolite.
Zeolite
Co-product :
Co-product :
Co-product :
Stillage :
Stillage :
1
1.
.
Carbon dioxide :
Carbon dioxide :
2
2.
. dry ice
used as animal feed

18. Reference :
Reference :
Reference :
Ethanol production, purification and analysis techniques: a review
𝘡𝘺𝘮𝘰𝘮𝘰𝘯𝘢𝘴 𝘮𝘰𝘣𝘪𝘭𝘪𝘴 as model system for production of biofuels &
biochemistry
Krueger & Keurger
𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴 𝘤𝘦𝘳𝘦𝘷𝘪𝘴𝘪𝘢𝘦 in the Production of Fermented
Beverages
other sources

19. Queries time.......
Queries time.......