405459524-Soap-and-detergents-manufacturing.pptx

Manufacturing process of soap and detergent

1. Soaps and Detergents Chapter#29 Pg#529

2. Soaps A soap or a detergent is a material, which when dissolved in water, aids the removal of dirt or foreign material from a surface. Soap is an alkali metal salt of a long chain fatty acid and is manufactured using animal fat or vegetable oil. Soaps are divided into two main classes; toilet soaps and industrial soaps. It has been generally accepted that the consumption of toilet soap is a reliable guide to the standard of living of a country.

3. History The washing industry has roots over 2000 years in the past. Soaps was never discovered but made from crude mixtures of alkaline and fatty materials. Pliny the elder--------manufacturing of soft and hard soaps. Up to 18 th century soap was considered as mechanical mixture. Chevreul corrected this misunderstanding. Domeier developed recovery of glycerin. Leblanc developed method of sodium carbonate from sodium chloride. Shortages of raw materials after world war 1 led G ermans to development of detergents. These were short chain alkyl naphthalene sulphonate. In 1920—1930 short chain converted to long chain then in 1950 to branched chain then after 1960 to long chain due to biodegradability.

4. Uses and economics In 1981 total soap shipment cost was 10701 million dollars; domestic soap cost 1300 million dollar and domestic detergent was 4000 million dollar. Remaining was industrial soap. Household uses include laundry products, toilet soaps, shampoos, dishwashing pdts , cleaners. Industrial soaps include special surfactants for hospital germicide. Fabric conditioner. Emulsifiers for cosmetics, wetting agents for agricultural chemicals, enhanced oil recovery from worked out oil wells.

5. Detergents Detergents differ from soaps in their action in hard water. Soaps make ppt after reacting with Ca and Mg of hard water, this reduces the cleaning action of soap. While detergents do react with Ca and Mg of hard water but donot produce ppt hence no effect on cleaning action. Detergents have been divided into 4 groups; 1. anionic 3. non-ionic 2. cationic 4. amphoteric . Mostly these are anionic and are sodium salts of organic sulfate or sulfonate. Their formulation differ with desired characteristics; Maximum cleaning 2. maximum cleaning/unit price 3. max biodegradability Soil removal is done by wetting, emulsifying, dispersing and solubilizing of soil. Detergent molecules produce micelles in water. Hydrocarbons parts of the molecule are on the inside of micelle and polar groups are on outside. Detergents and soaps have water attracting(hydrophilic) group on one end of molecule and water repelling(hydrophobic) group on the other side.

6. Raw materials Large volumes of surfactants are produced by soaps and detergents companies in final form. LAS( Linear alkyl benzene sulfonate ) and fatty alcohol sulfate produced in million of tons. Inorganic materials like oleum , caustic soda, sodium phosphate and additives are purchased. Surfactants: “ any compound that affects or reduce surface tension when dissolved in water or water solutions”. Soaps are such materials but this term is usually used for sodium salts of high molecular weight alkyl sulfates or sulfonates . The cleaning process consists of : Thoroughly wetting the dirt and the surface of article Removing the dirt from surface Maintaining the dirt in the suspension

7. Classification . The hydrophobic portion is the hydrocarbon group containing 8—18 carbon atoms. A benzene ring may replace some of carbon atoms in the chain like C 12 H 25---- , C 9 H 19 .C 6 H 4--- . The hydrophilic group may vary widely. Anionic ---OSO 4 , SO 3 . Cationic ---N(CH 3 ) 3 OR C 5 H 5 N. Nonionic ---(OCH 2 CH 2 ) n OH .

8. Biodegradability Water pollution control abatement and engineers suggest that surfactants must be readily decomposable by microbial action of sewage treatment. Some surfactants like tetra propylene derived alkyl benzene sulfonate degrade slowly and leave a persistent residue. The ease with which a surfactant decompose by microbial action has been defined as its biodegradability. Rate of biodegradation is determine in terms of parts per billion through various tests.

9. Straight chain alkyl benzene Biodegradable detergents are made from n-alkanes and those are produced from petroleum fraction. n-alkanes are separated from kerosene by adsorbtion using molecular sieves. Branched chain and cyclic alkanes have larger diameter which makes separation possible. Other method of separation is by reacting with urea or thio -urea. Urea absorbs n-alkanes while thio -urea absorbs branched chain alkanes. The crystalline adduct formed can be decomposed in hot water by heating at 80-90C. Linear olefins are prepared by; Dehydrogenation of paraffins Polymerization of ethylene Cracking paraffin wax Dehydrohalogination of alkyl halides

10. Manufacture of fatty acids and alcohols Fatty acids are produced from hydrolysis of fats using zinc oxide catalyst. There are two methods for producing fatty alcohols; Ziegler catalytic procedure for converting a-olefins to fatty alcohols Methyl ester hydrogenation process Ziegler procedure : Gaseous ethylene is converted to higher Al tri-alkyls by the action of Al tri-ethyl Chain growth reaction Displacement reaction 1. thermal decomposition 2. regeneration of ethyl Oxidation reaction Hydrolysis (acidolysis) Fatty alcohols from methyl esters: Methyl esters of fatty acids are hydrogenated to produce fatty alcohols. T hese methyl esters are produced by reacting fatty acids triglycerides with methanol in the presence of sodium methylate catalyst. For this tallow and coconut triglycerides are first dried by flashing at 150C at 16.6kpa then mixed with methanol. Methyl exchange esterification occurs. Mixture is given time to settle down into two layers; upper layer containing methanol and ester while bottom layer containing methanol and glycerin.

11. Hydrogenation of methyl esters takes place in 3 reactors. Catalyst used is Copper 2 and Copper 3 chromite. The reaction take place at 21Mpa and 260-315C. Hydrogen gas is used for heating and mixing also. Suds regulators: Suds regulation is necessary for surfactants to do an efficient cleaning in washing machines. This is done by combining different types of detergents and soaps. Foam inhibition is carried out by long chain fatty acids, fatty acids amides, carboxylic acid esters and aminotriazines. Builders: Builders boost detergent power. Sodium tripoly phosphate and tetra sodium pyrophosphates have been used for this purpose. They sequester water hardening ions and prevent re-deposition of soil on the fabrics. During 1960s algae growth and eutrophication of lakes were associated with phosphates, due to which phosphates were banned. Replacing compounds were NTA(nitrile tri-acetic acid) but in 1970 it was also found carcinogenic and banned. Then citrates, silicates and carbonates were introduced. Zeolite is a very strong booster.

12. Additives : Corrosion inhibitor; sodium silicates Anti re-deposition agents; carboxy methyl cellulose Tarnish inhibitors; benzotriazole Fabric brighteners Bluing's; ultramarine blue Antimicrobial agents Bleaches

13. Manufacture of detergents:

14. Sulfonation Sulfation Neutralization Prilling Dominant bath/circulating heat exchanger

15. Soap making Raw materials Animal fat grease coconut oil Soap manufacturing