Question

Describe the method of production of ethanol by fermentation reaction.

Answer 1

Industrial production of ethanol by fermentation reaction is as follows: First glucose and fructose are formed by fermentation reaction of sugarcane juice, juice of fruits or grapes, molasses(the waste which is without sugar after removal of sugar from sugarcane is called molasses)etc., in the presence of enzyme invertase.
$\underset{Sugarormolasses}{C_{12}{H}_{22}{O}_{11}}+H_{2}O\stackrel{Invertase}{⟶}\underset{Glucose}{C_6{H}_{12}{O}_6}+\underset{Fructose}{C_6{H}_{12}{O}_6}$
Ethanol and carbon dioxide are formed by fermentation of this glucose or fructose in the presence of enzyme zymase. Both the enzymes, invertase and zymase are present in yeast.
$\underset{Glucoseorfructose}{C_6{H}_{12}{O}_6}\stackrel{Zymase}{⟶}\underset{Ethanol}{2C_2{H}_{5}OH}+2C{O}_2\left(g\right)$
Ethanol is obtained as a mixture of $95\%$ ethanol and $5\%$ water which cannot be further concentrated but pure ethanol is obtained by membrane technology.