Question

Explain the preparation of ethyl alcohol from molasses.

Answer 1

When sucrose is crystallized from concentrated sugar cane juice, dark brown coloured mother liquor is left which is called molasses. It is diluted with water, acidified with dil sulphuric acid and then ammonium sulphate is added. Then yeast is added and temperature is kept at 30 deg C for 2-3 days. Ethanol is formed by fermentation. The contents are filtered and the filtrate is distilled.
$\underset{\text{sucrose}}{C_{12}{H}_{22}{O}_{11}}+H_{2}O\stackrel{\text{invertase}}{\to }\underset{\text{Glucose}}{C_6{H}_{12}{O}_6}+\underset{\text{Fructose}}{C_6{H}_{12}{O}_6}$
$\underset{\text{Glucose or Fructose}}{C_6{H}_{12}{O}_6}\stackrel{\text{zymase}}{\to }\underset{\text{Ethyl alcohol}}{2C_2{H}_{5}OH}+2C{O}_2\uparrow$