Commercially Important Alcohols: Methanol, Ethanol, Beverages

Commercially Important Alcohols: Organic compounds like carboxylic acid, amines, alcohols, ethers, etc., have numerous applications in our daily life. Each functional group has its own applications. Alcohols are famous due to their application in alcoholic beverages. In the article Commercially important alcohols, you will understand the uses of methanol, ethanol, industrial alcohols like absolute alcohol, denatured alcohol, power alcohol, alcoholic beverages, etc.

What is Alcohol?

The organic compounds with one or more hydroxyl groups \(( – {\rm{OH}})\) bonded to an aliphatic carbon atom are called alcohols. The general formula of alcohol is \({\rm{ROH}}\).

Alcohols are classified into aliphatic and aromatic based on the attachment of hydroxyl to the carbon.

Alcohols in which the hydroxyl group \(( – {\rm{OH}})\) is attached to the alkyl group are called aliphatic alcohols.

Example: Methanol \(\left( {{\rm{C}}{{\rm{H}}_3}{\rm{OH}}} \right)\), Ethanol \(\left( {{{\rm{C}}_2}{{\rm{H}}_5}{\rm{OH}}} \right)\), Propanol \(\left( {{{\rm{C}}_3}{{\rm{H}}_7}{\rm{OH}}} \right)\), etc.

Alcohols in which the hydroxyl group \( – {\rm{OH}}\) is present in the side chain of an aromatic hydrocarbon known as aromatic alcohols (benzylic alcohol).

Example: Benzyl alcohol \(\left( {{{\rm{C}}_6}{{\rm{H}}_5}{\rm{C}}{{\rm{H}}_2}{\rm{OH}}} \right)\).

What is Commercial Alcohol?

The alcohol that is used for commercial purposes is called commercial alcohol. The most common commercial alcohols are methanol (methyl alcohol, \({\rm{C}}{{\rm{H}}_3}{\rm{OH}}\)) and ethanol (ethyl alcohol, \({{{\rm{C}}_2}{{\rm{H}}_5}{\rm{OH}}}\)).

Uses of Methanol

Methanol is commonly called methyl alcohol. It is also known as wood spirit or wood alcohol because it was originally prepared by destructive distillation of wood. Its chemical formula is \({\rm{C}}{{\rm{H}}_3}{\rm{OH}}\).

Methanol is used:

1. As a solvent for paints and varnishes.
2. As an antifreeze for automobile radiators.
3. In the manufacture of formaldehyde which is very widely used in the manufacture of plastics.
4. For denaturing ethyl alcohol, that is to make it unfit for drinking purposes. Denatured alcohol is commonly known as methylated spirit.
5. As a motor fuel
6. In the manufacture of perfumes, drugs, and varnishes.

Uses of Ethanol

Ethanol is commonly called ethyl alcohol. Its chemical formula is \({{\rm{C}}_2}{{\rm{H}}_5}{\rm{OH}}\). It is the most important member of the alcohol series and is simply known as alcohol. It is also known as grain alcohol because it can be prepared from starch grains.

Ethanol is used as:

1. As an industrial solvent for paints, lacquers, dyes, varnishes, costumes, perfumes, etc.
2. In the manufacture of alcoholic beverages.
3. In the preparation of ether, chloroform, iodoform, acetaldehyde, acetic acid, etc.
4. In scientific instruments like thermometers and spirit levels.
5. As an antifreeze in automobile radiators.
6. As a preservative for biological specimens.
7. As a fuel in spirit lamps and stoves.
8. In hospitals, an antiseptic-like tincture of iodine is used, which is \(2 – 7\% \) iodine dissolved in ethanol and water mixture.
9. In the manufacture of drugs, flavouring extracts, perfumes, etc.
10. Ethanol (in concentrations ranging from \(1\% \) to \(25\% \)) is used as a solvent for some analgesics and mouthwashes.

Industrial Alcohols

Ethanol is one of the most important raw materials which is quite frequently used. It is sold in different grades of purity for different purposes. Some of them are:

1. Absolute alcohol: It is \(100\% \) pure ethanol. The fermentation of carbohydrates gives ethanol containing some water. The fractional distillation of aqueous solution of ethanol provides a constant boiling azeotropic mixture, which contains \(95\% \) of ethanol. To get \(100\% \) ethanol, a small amount of benzene is added with an azeotropic mixture and then distilled. Pure ethanol is distilled as the last fraction at \(351.1{\rm{ K}}\). Ethanol of different percentages is prepared from this and is used for different purposes like alcoholic beverages, fuel, solvent, etc.
2. Alcoholic beverages: Liquors used for drinking purposes contain alcohol as the principal intoxicating agent. These are also called alcoholic beverages. They are prepared from different substances and contain different percentages of alcohol. There are mainly two types of beverages: distilled and undistilled. Undistilled beverages are prepared from grapes and other fruit juices and are called wines. The liquors obtained from distillation have higher alcoholic content and have different grade names such as whisky, rum, brandy, gin, etc.
3. Methylated spirit or Denatured alcohol: It is \(95\% \) ethyl alcohol. To avoid the misuse of alcohol meant for industries, made unfit for drinking by mixing in ethanol with a small amount of methanol, some copper sulphate to give colour to it, and pyridine to give a foul smell. The process is called denaturation of alcohol, and the alcohol thus obtained is called methylated spirit or denatured alcohol. It is quite cheap and can be used for non-drinking purposes and particularly in industries. Methylated spirit is combustible; hence it can be used as a fuel in lamps and stoves. Methylated spirit is a component of glass cleaners.
4. Power alcohol: It is a mixture of \(20\% \) of ethanol and \(80\% \) gasoline. Since alcohol does not mix with petrol, thus solvent such as benzene or ether is added in small amounts. Due to the limited natural sources, petrol generally remains in short supply. The usage of power alcohol as a substitute for gasoline has promised a bright future in India because we can manufacture large quantities of alcohol from molasses.

Harmful Effects of Drinking Alcohol

Ethanol, when consumed in large quantities, tends to depress the central nervous system by slowing the metabolic processes. This may result in incoordination, mental confusion, and drowsiness. Consumption of small quantities of dilute ethanol causes drunkenness, and a person may feel relaxed after consuming alcohol but loses his sense of judgement. Muscular coordination may also be seriously impaired. Also, long-term consumption of alcohol leads to serious health problems.

The intake of methanol is more lethal and may cause death. It is oxidized to methanal in the liver and reacts rapidly with the components of cells, causing the coagulation of the protoplasm. It also affects the optical nerve that may cause blindness.

Summary

Alcohol is of the most important functional group of organic compounds due to its applications in different fields. In the article, Commercially important alcohols, you have understood the meaning of alcohol and commercial alcohol, uses of most common alcohols, i.e., methanol and ethanol and industrial alcohols like absolute alcohol, denatured alcohol, power alcohol, alcoholic beverages. Apart from this, you can recall the harmful effects of alcohol consumption.

FAQs on Commercially Important Alcohols

Q.1. What are the main commercial uses of alcohol?
Ans: Alcohols are commercially used in alcoholic beverages, as an industrial solvent, antifreeze in automobile radiators, in the preparation of ether, chloroform, iodoform, etc.,

Q.2. How is an alcohol produced commercially?
Ans: Alcohol is prepared commercially by fermentation.

Q.3. What are the medically important alcohols?
Ans: The medically important alcohol are ethanol, isopropyl alcohol and glycerol.

Q.4. Which alcohol is used in industry?
Ans: Ethanol (ethyl alcohol, \({{{\rm{C}}_2}{{\rm{H}}_5}{\rm{OH}}}\)) are used in industry.

Q.5. What are the principal uses of methanol, ethanol, and isopropyl alcohol?
Ans: Methanol is used as a solvent for paints and varnishes, as an antifreeze for automobile radiators, in the manufacture of formaldehyde, for the denaturing ethanol, as a motor fuel, etc.

Ethanol is used as an industrial solvent for paints, lacquers, dyes, varnishes, costumes, perfumes, etc., in the manufacture of alcoholic beverages, in the preparation of ether, chloroform, iodoform, etc., as an antifreeze in automobile radiators, etc.

Isopropyl alcohol is used as a solvent for drugs, cosmetics. It is also used in lotions and for the denaturation of ethanol.

Q.6. What are the medically important alcohols? Discuss their uses briefly?
Ans: The medically important alcohol are ethanol, isopropyl alcohol, and glycerol.

 In the hospital, an antiseptic like tincture of iodine is used, which is \(2 – 7\% \) iodine dissolved in ethanol, and water mixture. It is used in the manufacture of drugs.

Ethanol (in concentrations ranging from \(1\% \) to \(7\% \)) is used as a solvent for some analgesics and mouthwashes.
Isopropyl alcohol is used as a solvent for drugs and cosmetics. It is also used in lotions.

Glycerol is used for constipation, improving hydration, and improving certain skin conditions.

Q.7. How are alcohols manufactured commercially?
Ans: Alcohol can be manufactured commercially by fermentation of starch or sugar. In the fermentation process complex, organic compounds are broken down into alcohol by biological enzymes like invertase, zymase, etc.