Soaps and Soap manufacturing process

Soaps are from the class of surface-active agents or surfactants. Where the surface properties play the role of water like and dislike ability of the compound. A compound which shows attractiveness towards the water and dissolves in it called as hydrophilic compound and the opposite action of which the compound repel from water and do not dissolve but stay separately forming another layer and may dissolve organic compounds is called hydrophobic. By using this mechanism a surfactant is a molecule which has these two compounds as head and tail and acts like a link binder between the water and dirt or oil.

 Soaps are the chemical compounds of the type R.COO.M where the part “R.COO” is fatty acid radical representing oleic, stearic, palmitic, lauric and myristic. These are usually present in soaps as mixture based on glyceride raw materials. ‘M’ is an alkali element such as Na or K. 

Types of soap manufacturing process:

1. Batch saponification process:
 The most famous Twirchell process where acid hydrolysis of glycerides is done along with alkali addition, or even by direct saponification using concentrated caustic. This process used for small-scale and domestic level production

 2. Continuous Hydrolysis and Saponification Process: The is followed for industrial large-scale production.

Chemical Reactions:

 Fat splitting:

 (R.COO)₃.C₃H₅ + 3H₂O à 3R.COO.H + C₃H₅(OH)₃

Saponification:

 R.COO.H + M.OH à R.COO.M + H₂O

 Where M is mostly alkali earth metal Na and K

Commonly used fatty acids 

Raw materials: Soaps are derived from triglycerides, a compound having three ester-linked fatty oils and alkali earth metal hydroxides like caustic soda or potassium hydroxide. The fatty acid molecule present in the oil is the main part of starting material.
Process flow sheet:

Continuous process for fatty acids, soap and glycerin

General Consideration of Raw Materials in Soap Making Process

Soaps manufacture from fatty acid and oil for the variety of soap products