Question

What is the side product of soap industry? Give reactions showing soap formation.

Answer 1

Glycerol is obtained as a side product during the formation of soaps.

The process of soap formation is referred as saponification. It is the process that involves the conversion of fat or oil into soap and alcohol by action of heat in the presence of aqueous alkali.

\[\begin{array}{cc}
\ce{O}\phantom{..........................................}\\
||\phantom{..........................................}\\
\phantom{.}\ce{CH2 - O - \underset{}{C} - C17H35}\phantom{..................................}\ce{CH2 - OH}\phantom{.}\\
\phantom{..}|\phantom{..........}\ce{O}\phantom{............................................}|\phantom{..........}\\
|\phantom{..........}||\phantom{.....................................................}\\
\phantom{}\ce{CH - O - C - C17H35 + \underset{hydroxide}{\underset{Sodium}{3NaOH}} -> \underset{sterate}{\underset{Sodium}{3C17H35COONa}} + CH - OH}\phantom{.}\\
\phantom{..}|\phantom{..........}\ce{O}\phantom{............................................}|\phantom{..........}\\
|\phantom{..........}||\phantom{.....................................................}\\
\phantom{.}\ce{\underset{of stearic acid (Fat)}{\underset{Glyceryl ester}{CH2 - O - C - C17H35}}\phantom{...................................}\ce{\underset{(or Glycerine)}{\underset{Glycerol}{CH2 - OH}}}\phantom{}}
\end{array}\]