Ordinary rectified spirit is called industrial alcohol. To ensure that industrial alcohol is not used for human consumption, poisonous materials like methanol, pyridine or mineral naphtha are added to the rectified spirit to denature it. This mixture of 90% ethanol with methanol is called methylated spirit.
Power Alcohol
Absolute alcohol is miscible with petrol but industrial alcohol is not. However, in the presence of benzene, industrial alcohol can be mixed with petrol. This alcohol used for generating power is called power alcohol.
Alcoholometry
Alcoholometry is the process of determination of the strength of alcohol. This is done by determining its specific gravity and reading the percentage of alcohol against that value in the ready reference tables.
By-products of the Alcohol Industry
Carbon Dioxide
This is evolved during fermentation. It is collected and can be sold as a by-product (fire extinguisher, aeration of soft drinks).
Acetaldehyde
During rectification of alcohol by the fractional distillation method, the first fraction contains acetaldehyde.
Fusel Oil
The last runnings obtained by rectification contains mainly high boiling alcohols called amyl alcohols. This is called fusel oil and is used for preparing amyl alcohols or acetates.
Spent Wash
The residue left in the distillation still after distillation of wort, contains nitrogenous matter. This is used as cattle feed.
Potassium Hydrogen Tartrate
During fermentation of grape juice, a brown crust is formed at the top and is called argol, which contains potassium hydrogen tartrate. It is used for the prepartation of tartaric acid and Rochelle salt (potassium sodium tartrate).
