Soaps & Detergents Soaps & Detergents

1. MD : MOYNUL ISLAM
ID: 20151107004

2. Soaps & Detergents

13. Soaps
Soaps are water-soluble sodium or potassium salts of higher fatty acids such as
oleic acid (C17H33COOH), stearic acid (C17H35COOH), palmitic acid
(C15H31COOH), lauric acid (C11H23COOH) are called soap.
Soaps are made from fats and oils, or their fatty acids, by hydorlysis and then
treating them chemically with a strong alkali.
CH2-OOC-C17H35 CH2-OH
CH-OOC-C17H35 +3H2O 3C17H35COOH+ CH-OH
CH2-OOC-C17H35 CH2-OH
Tristearin
Stearic acid
3C17H35COOH + 3NaOH C17H35COONa +3H2O
Example-Toilet, laundry soap, shaving soap, liqiup soap etc.

14. Soap ions consist of two parts, that is the head that consists of the anion region, ionic and also
called the hydrophilic region which dissolves in water. Another part is the tail that consists of
hydrocarbon region and its molecule has covalent characteristics. Its also called the hydrophobic
region which dissolves in grease or oil(dirt).
The soap molecules will dissolves in water and reduces the surface tension of water. Water wets
the dirty surface. The hydrophilic region dissolves in water whereas the hydrophobic region
dissolves in dirt such as grease. Grease is lifted off the surface of the material and suspended in
water. The tail region emulsifies and breaks up the grease into small drops.
Cleaning action of soap

15. Raw materials used for soap preparation
Fats or tallow
Tallow is the principle fatty material used to prepare soap. The quantities used are about
three-fourths of the total oils and fats consumed by the soap industry. It contains the mixed
glycerides obtained from the solid fat of cattle. The solid fat is digested with steam; the
tallow forms a layer above the water so that it can easily be removed.
Fatty oils
-Coconut oil-----it contains large proportions of the very desirable glycerides of lauric and
myristic acids. It is used in order to get moderately soluble and hard soap. Its melting point
is 20-250C.
-Palm oil--- palm oil contains 6% free fatty acid. It is colored. So before use, it is bleached
in order to get colorless oil. It is used for making toilet soap.
-Olive oil--- It is used for the finer quality toilet soap
-Castor oil--- It is used for the production of transparent soap.
 Greases
Greases are (20%) the second most important raw materials in soap manufacturing. They
are obtained from hogs and smaller domestic animals. They are refined by steam rendering
or solvent extraction.

16. Some inorganic chemicals such as Na2CO3, Na3PO4, NahCO3, borax etc. are used to improve
the quality of the soap which are called soap builders. Soap builders are used for the following
purposes
To promote the cleansing power.
To reduce the overall costs.
To enhance the effectiveness of the soap.
To prevent the redeposition of the soil from the wash water on the fabrics.
To soften the hardness of the water.
To control the alkalinity of the solution.
To prevent the formation of precipitation in hard water.
To prevent the wastage of soap.
To decrease the rapid solubility of soap
To increase the strength and odor of the soap.
Soap builders

17. Auxiliary Raw Materials
Caustic soda, NaOH---it is one of the principle raw materials used in the saponification process.
It is used in making of hard soap.
Caustic potash KOH-------it is used in making of soft soap
Rosin----Rosin is a plant exudation product which is mainly contains pimaric and abietic acid.
Rosin is used for the following purposes
--to make lather formation faster
-- To increase the cleansing action of the soap
-- To soften the hard soap
Fillers/Aditives—fillers are used to increase the bulk or weight of the soap without affecting the
detergency. Some fillers are added such as
a) Talc (5-10%); b) Starch (2%); Glauber salts (Na2SO4.10H2O); d) Pearl ash etc.
Coloring agents– Organic dyes and inorganic pigments are generally used. Common coloring
matters are---
a) Methyl violet for violet shade; b) Bismark brown for brown; c) Rhodamine for red; d) Zinc
oxide for white; e) Ultramarine or methyl blue for blue shade ; f) Cosin for pink shade.
Perfume and perfume fixatives
Perfume may be natural or synthetic. Natural perfumes are sandal wood oil, lemon grass oil, clove
oil, eucalyptus oil, lavender oil etc. Synthetic perfumes are jasmine (benzyl acetate), rose (phenyl
ethyl alcohol) and musk (benzoate).
Certain perfume fixatives such as Tolu-balsum, Gum-benzoin etc. are used.

18. Process of manufacture of soap
1.Full-boiled process
•Batch-kettle process or saponification process
•Modern /continuous/splitting process or hydrolysis process
1.Semi-boiled process
2.Cold-made process
3.Neutralization process.

20. Olive oil
storage
Palm oil
storage
Tallow
storage
Coconut
oil storage
Blending
tank
ZnO
Deaeration
under vacuum
Spurge
ring
Water
Hydrolyzer
485 0F
600 psi
Vaporizer
Tar
separator
As steam
water
Glycerol solution (12%)
(hydrolysis)
50%NaOH
Neat Soap
Vacuumfractionator
Low MW fatty acid
Neutralizer
2'
65'
Modern /continuous/splitting process or hydrolysis process

21. Batch process Continuous process
1. Raw materials are fed at a time and after complete
saponification the soap is taken out.
1. Raw materials are fed continuously and the soap is also
taken out continuously.
2. Bleaching of the colored fats or oils is required. 2. Pretreatment of fats or oils is not required.
3. Glycerine solution obtained is only 4% 3. Glycerine solution obtained is only 12%
4. The process conditions are rigid and cannot be changed. 4. The process has flexibility in its control.
5. Large space and manpower are required. 5. Small space and manpower are required.
6. Process time is 7 days. 6. Process time is only 6 hrs.
Difference between batch process & continuous process

22. Detergent

23. A detergent is a surfactant or a mixture of surfactants with "cleaning properties in
dilute solutions. These substances are usually alkylbenzenesulfonates, a family of
compounds that are similar to soap but are more soluble in hard water, because the
polar sulfonate (of detergents) is less likely than the polar carboxyl (of soap) to bind
to calcium and other ions found in hard water.
Detergents are synthetic organic chemicals which promote better surface tension
lowering than soaps.
Detergent

24. Why detergents?
Owing to the shortage of fats or oils, soap manufacturing becomes so much expensive.
In the detergent manufacturing, fats and oils are not used. So a large amount of edible fats
and oils become available for human consumption.
Detergent is superior in its action to soap even in hard water i.e. the soap forms insoluble
compounds with Ca2+ and Mg2+ present in hard water. This insoluble compounds reduce
the foaming and cleansing action. But detergent don’t form insoluble compounds.
2RCOONa + MgSO4 (RCOO-)2Mg2+ +Na2SO4
Soap insoluble compund
2R-Ar-SO3Na +MgSO4 [R-Ar-SO3-]2 Mg2+ + Na2SO4
Soluble compound

25. Types of detergent
Anionic detergents– those detergents which produce anion (R-) in water or solution. Anionic
detergents dissociate into a long chain anion which acts as the hydrophilic end and the long chain
carbon as the hydrophobic end. Example: Alkyl benzene sulphonate, Alkyl sulphate, Alkyl
benzene ether sulphonate,
Cationic detergent- those detergents which produce cation (R+) in water or solution. Cationic
detergents are quaternary ammonium salts of acetates, chlorides, or bromides These detergents
have no strong detergent characteristics but have strong germicidal properties.
Exam: cetyltrimethylammonium bromide

26. Non-Ionic- Molecules of these detergents do not contain any ions. These detergents
are esters of alcohols having high molecular mass. They are obtained by reacting
polyethylene glycol and stearic acid.
Example: Alkyl arul ethylene derivatives, fatty acid amides etc.
 Amphoteric detergents- those detergents contain both cationic and anionic groups are
called amphoteric detergents.
Example: Lauryl sarcozinate.

27. Detergent builders
Some compounds which are added to detergents during preparation for lowering surface tension
of water and extending foam for the prevention of redeposition of soil and dirt on the fabric, to
increase the effectiveness, brightness, and reduce the overall cost of detergent. These
compounds are called detergent builders.
Six types of detergent builders are used----
1. Phosphates
2. Sodium carboxy methyl cellulose
3. Fabric brightners or fluorescent dyes
4. Corrosion inhibitors
5. Antimicrobial agents
6. perfumes