Ethyl alcohol production

1. SRI PARAMAKALYANI COLLEGE
REACCREDITED WITH A+ GRADE WITH A CGPA OF 3.39 IN THE THIRD CYCLE OF NAAC
AFFILIATED TO MANOMANIUM SUNDARANAR UNIVERSITY, TIRUNELVELI.
ALWARKURICHI 627 412, TAMIL NADU, INDIA
POST GRADUATE & RESEARCH
DEPARTMENT OF MICROBIOLOGY
(Government Aided)
ACADEMIC YEAR 2022-2023
IV SEM CORE: INDUSTRIAL MICROBIOLOGY
UNIT- V
Solvent (Ethyl alcohol, butane diol)
Submitted to,
Dr. S.VISWANATHAN Ph.D.
Assistant Professor and
Head,
Department of
Microbiology.
SPKC.
Submitted by,
S. AZHAGAMMAL
Reg.
No:202112325161
07
II M.Sc.
Microbiology

2. Solvents ethyl alcohol and butanediol

3. SOLVENT
• A solvent is a substance that dissolves a solute, resulting in a
solution.
• A solvent is usually a liquid but can also be a solid, a gas, or a
supercritical fluid.
• In chemistry, solvents-which are generally in liquid form-are
used to dissolve, suspend, or extract other materials usually
without chemically changing either the solvents or the other
materials

4. Characteristics of solvents
• Available in bulk quantity
• Biocompatibility
• Chemical and thermal stability.
• Favorable distribution coefficient for product and substrate.
• Favorable properties for product recovery.
• High selectivity
• Inexpensive
• Low emulsion forming tendency
• Low aqueous solubility
• Non biodegradability
• Non hazardous

5. Type of solvents

6. Industrial solvents
 Industrial solvents are widely used in chemical as well as fermentation industries.
 For example, ethanol is used as a solvents and precursor of many synthetic
chemicals.
 On the other hand, extraction procedures of certain antibiotics from fermented
broth [e.g., penicillin] need suitable solvents. These chemical compounds have
been produced by fermentation process`
 Today fermentation have virtually disappeared as a result of the development of
chemical ones. This has happened for the following reasons;
 1. High prices of the fermentable substrates.
 2. Increasing economic competition fro the petrochemical industry.
 These chemical compounds are produced as by products during the refining of
petroleum

7. • Ethanol is a type of alcohol produced by fermentation of
sugar and starches or cellulosic biomass.
• It is a clean-burning, high-octane fuel that is produced
from renewable sources like sugar, starch and renewable
wastes.
• Ethanol is a flammable and oxygenated hydrocarbon
liquid.
• The primary feedstock for ethanol production is corn.
• Secondary feedstock include sugarcane, sugarbeets and
cellulose.
• Chemical formula is C2H5OH.
Ethanol Production

8. Physical properties of ethanol
● Colorless liquid
● Molecular weight
● Pleasant alcoholic odor detectable at 49 to 716ppm.
● Miscible with water and most organic solvents
● Boiling point : 78.3 ⁰C in the anhydrous state.
● Melting point : -114.1⁰C
● Specific gravity : 0.789- indicates it is lighter than water.
● Vapor density : 1.6-indicates that it is heavier than air.

9. Principle of ethanol production
• Alcohol fermentation/Ethanol fermentation is a biological process in which sugars such as
glucose, fructose and sucrose are converted into cellular energy and thereby produces ethanol
and carbon dioxide as metabolic waste products.
• Since yeast performs this conversion in the absence of oxygen, alcoholic fermentation is an
anaerobic process
• For many years the alcohol was produced by chemical means through the catalytic hydration
of ethylene.
• However, in the developing countries, microbial fermentation processes are preferred for the
production of alcohol.
• This is mainly because of the cheap raw materials available.
• Ethanol is now-a-days produced by using sugar beet, potatoes, corn, cassava, and sugar cane.

10. Biosynthesis of Ethanol

11. STEPS INVOLVED IN ETHANOL PRODUCTION:
1. Selection of Microorganisms.
2. Selection of raw materials.
3. Preparation of fermentation medium.
4. Preparation of inoculum(culture).
5. Fermentation process.
6. Recovery process

12. Microorganisms used in Ethanol fermentation
Organisms are selected by;
• High growth and fermentation rate
• High ethanol yield
• Osmotolerance [ability to grow in an
environment with a high osmotic pressure].
• Low pH
• High temp
• Nature of the substrate used
• Ethanol and glucose tolerance [allows
conversion of concentrated feeds to
concentrated products]
Microorganisms Source of
carbohydrate
yeasts
Saccharomyces
cerevisiae
Starch, sugar
Saccharomyces uvarum Starch, sugar
Saccharomyces
carlsbergensis
Starch, sugar
Kluyveromyces fragilis Starch, sugar
Kluyveromyces lactis Starch, sugar
Candida brassicae Starch, sugar
Candida, utilis Starch, sugar
Bacteria
Zymomonas mobilis Starch
Candida
pseudotropicalis
Lactose, whey

13. Selection of raw materials.
3 different raw materials are used.
1. Starchy Raw material: Potato starch, Com
starch.
2. Cellulosic Raw material: Waste sulphate
(sulphide) liquor.
3. Saccharide Raw material: Glucose or any
monosaccharide.

14. Preparation of inoculum.
 Aeration and agitation are necessary, pH: 4.8-5 ,Temperature: 8-30°C
 It is important to produce large size of inoculum.
 10 ml starter culture inoculated into 100mI sterile medium.
 After incubation, 100ml sterile medium is inoculated into 10-40Lt of
sterile basal medium and incubate for particular time.
 10-40Lt of basal medium having growth used for inoculation of 10-40
gallons of sterile basal medium and incubate it further. after incubation it
is used as “Inoculum”.

15. Preparation of Fermentation Medium
• The raw material used for the preparation of fermentation medium depends upon the
agricultural produce of the country.
• For example, cane-molasses is used in India. Starchy material subjected to
saccharification, where starch gets hydrolysed, thus forming fermentable sugars,
maltose and glucose.
• The optimum sugar concentration ranges between 10 to 18% in the fermentation
medium. Also, a suitable source of nitrogen, such as ammonium sulphate, is added
to meet the biotin deficiency in the beet - molasses.
• The pH of the medium is adjusted to 4-8 to 5. the pH can be adjusted by the use of
H2SO4 or lactic acid.
• Alternatively, it can be adjusted by growing lactic acid bacteria prior to
fermentation. It is not necessary to sterilize the fermentation medium.
• This is mainly owing to highly acidic pH which hinders the growth of undesirable
bacteria. However, pasteurization of the fermentation medium maybe practised.

16. Fermentation process
• Fermenter is filled up to 3/4% portion with
fermentation medium.
• Fermentation medium is sterilized by
pasteurization at 147⁰F.
• Cooling coils/cooling jackets are used to
cool the medium.
• Inoculum was added.
• Temperature of medium maintained up to
28-30⁰C.
• Addition of nitrogen source. Eg:
Ammonium sulphate.
• pH of medium should be 4.8-5.0
• Process takes 70 hours for production of
ethanol.

17. Product recovery
• The cell mass is separated before distillation by either centrifugation or sedimentation.
• It is then distilled in analyzer and rectifier columns to get ethyl alcohol also called
rectified spirit and fuel alcohol (higher alcohols).
• A mixture containing 95.6% ethyl alcohol and 4.4% water is obtained by fractional
distillation. After distillation, the spent wash and bottom sludge are drained out as
distillery waste. The product is marketed as rectified spirit, denatured spirit or special
spirit.
• Zymomonas mobilis produces up to 120 g ethanol per litter per hour.
• Large distilleries employ, generally, special rectifier column called as coffey’s still
which consists of two columns called as the analyzer and the rectifier.
I. The Analyzer: The analyzer is a vertical tower. Consists of columns arranged in a
zigzag manner. The fermentation liquid is allowed to flow down the analyzer and
simultaneously steam is allowed to move up the tower from its bottom. Alcohol present
in the fermentation liquid Vaporizes and its vapours collect at the bottom of the tower
and are made to flow into the rectifier

18. II. The Rectifier: Just like analyzer, the rectifier is also a vertical tower. It consists of
specially designed fractionating columns with a number of chambers. The less volatile
constituents (the slop and fuel oil) gradually condense and are drawn off from a higher
point of the still. The temperature at the higher point of still is roughly equal to the boiling
point. The head products, which are very less, contain aldehydes, formic esters etc. Owing
to their greater velocity, pass out through the top of the column along with a small quantity
of uncondensed alcohol.

20. Uses of Ethanol
1. Pharmaceutical products
2. Cosmetics
3. Alcoholic beverages
4. Perfume
5. Varnish
6. fuel additive/extender
7. Paints
8. Polyester fiber/films
9. Ink
10. Anti freeze

21. BUTANEDIOL
• 2,3-butanediol also called diol or 2,3-butylene glycol and possible source for 1,3-butadiene and it
used in the synthesis of rubber
• It is also a source for a permanent type antifreeze. Moreover, other compounds, readily derived from
this mother compound, include methyl ethyl ketone, methyl vinyl carbinol methyl viny ketone, the
last two compounds are use in the plastics industry. 2,3-butanediol exists in three stereoisomeric
forms of 2,3-butanediol, or 2,3-butylene glycol, all of which a produced by bacerial fermentation.
CH3
H—C—OH
H—C—OH
CH3
Meso-2,3-butanediol
CH3
HO—C—H
H—C—OH
CH3
D-[-]2,3-butanediol
[levorotatoru form]
CH3
H—C—OH
HO—C—H
CH3
L []-2,3-butanediol
[dextrorotatory from]

22. • A mixture of the dextrotrotatory and meso forms of 2,3-butaneediol is produced by strains of
aerobacter aerogenes.
• The levorotatory form of 2,3-butaneediol is produced characteristically by bacillus polymyxa.
• D-[-]2,3-butanediol as the chief substance formed by b.polymxa in grain mashes.
Physical Properties. The 2,3-butanediols, C4H10O2, are colorless and odorless, strongly hygroscopic,
oily liquids or crystals with a sweet taste. They are miscible with water and easily soluble in
lowmolecular mass alcohols andketones.
• Nevertheless, butanediol is sometimes used as a substitute for other illegal substances such as
gamma butyrolactone (GBL) and gamma hydroxybutyrate (GHB).
• Butanediol is a chemical that is used to make floor stripper, peint thinner and other solvent
products. It’s illegal to sell butanediol for use as medicine.
• The demand for synthetic rubber in World War II greatly stimulated research on the production
and properties of 2,3-butanediol in this country and in Canada, since it could be converted to 1,3-
butadiene, a substance used in the production of rubber of the Buna type and that there are many
potential uses for these, such as for antifreeze agents, solvents, softeners, and plastics.
• The raw material of fermentation substrates, it appears that ethyl alcohol fermentation also uses
the same raw materials.

23. Microbial Production Of Butanediol
• Microorganisms
• 2,3- butanediol is known to be produced by a rang of sugar or
citrate fermenting microbes.
• The organisms are -
Bacillus amyloliquefaciens
Bacillus subtilis
Enterobacter aerrogenes
Klebsiella pneumoniae
Bacillus polymyxa
Serratia marcescens

24. Metabolic pathway for the production of 2,3-butanediol

26. Recovery
• Recovery of 2,3 butanediol from fermented mashes is rather difficult because of its high boiling
point (179-180°C). The product was recovered by the various procedures:
• They are - spray drying, drum drying, chemical conversion, dialysis, solvent extraction and steam
stripping.
• In most of these procedures, the 1% step consists of elimination of ethyl alcohol.
• Therefore, liquor is subjected to filtration or screening, followed by concentration by evaporation.
• With grain fermentations the most feasible procedure of recovery was found to be vapour phase
steam extraction.

27.  2,3-Butanediol (at least 80% mesoisomer, the rest racemic mixture) is used as across-linking
agent for naphthalene-1,5-diisocyanatein the production of specific hard-rubber products
(Vulkollan). Derivatives of 2,3-butanediol are important as insecticides (Sapecron: acetal
with N-methylcarbamate of salicylic aldehyde) and as intermediates in the pharmaceutical
industry. 2,3-Butanediols have some interest as humectants and in the synthesis of polymers
and plasticizers.
 which is widely used in Chemicals, food, fuels, aeronautical and other fields. e 2,3 -
Butanediol (also called as diol or 2,3butylene glycol) is a possible source for 1,3butadiene
(used in the synthesis of rubber).
 It is also a source for a permanent -type antifreeze for its low freezing point
 Moreover, other compounds, readily derived from this mother compound 2,3butanediol
includes methyl ethyl ketone, methyl vinyl carbinol and methyl vinyl ketone.
 Methyl vinyl carbinol and methyl vinyl ketone are used in the plastic industry.
 The dehydration esterification forms of 2,3-butanediol is the synthesis of polyimide
precursors, which can be applied to ° Drugs, cosmetics, lotion
 In China, 2,3 - butanediol is have been added to the spirits to improve the wine flavour
USES

28. Reference
Industrial microbiology A.H. Patel
Industrial microbiology Prescott / Dunn
https://www.researchgate.net/publication/328012040_Cost-_and_Energy-Efficient_Butanol-
Based_Extraction-Assisted_Distillation_Designs_for_Purification_of_23-
Butanediol_for_Use_as_a_Drop-in_Fuel
https://academic.oup.com/jimb/article/46/11/1583/5996812