Question

What is hydrogenation? What is its industrial application?

Answer 1

- Hint: As the name suggests, hydrogenation is related to the addition of hydrogen. Hydration is a process of reduction and it reduces the compound that undergoes hydration. The hydration process usually takes place in the presence of a catalyst.

Complete step-by-step solution -
 The chemical reaction in which molecular hydrogen ($H_2$) is added to another compound generally in the presence of catalysts like palladium (Pd), nickel (Ni) or platinum (Pt). The compound in which hydrogen is added is generally unsaturated organic compounds i.e. the compounds that have double or triple bonds in them. This process is a reduction process in which double or triple bonds of an organic compound are reduced to single bonds. In other words, unsaturated organic compounds are converted to saturated organic compounds.
Let us see an example of the hydrogenation reaction.
$C{H}_2=C{H}_2+H_2\stackrel{Pd}{\to }C{H}_3-C{H}_3$
As we can see in the above reaction, the molecular hydrogen is added to ethene (${CH}_2{CH}_2$) with the help of the catalyst Palladium (Pd) to form ethane (${CH}_3{CH}_3$). This reaction is hydrogenation.
Catalytic hydrogenation has various uses in different industries.
-Food Industry: Catalytic hydrogenation is largely used in food industries for the processing of vegetable oils. The source of vegetable oil is polyunsaturated fatty acids that contain more than one double bond. Fatty acids are carboxylic acids that have long chains of carbon atoms. These polyunsaturated fatty acids are partially reduced. Most of the double bonds are reduced into single bonds by the addition of hydrogen. This control of hydrogenation is done by lowering the amount of hydrogen, catalyst, reaction time, and temperature.
-Petrochemical industry: In petrochemical industries, alkenes and aromatic compounds are converted into saturated alkanes (paraffin) and cycloalkanes (naphthenes) by using hydrogenation. This is done because alkanes and cycloalkanes are less reactive and less toxic.

Note: Don’t confuse hydrogenation with hydration. As we know, hydrogenation is the process of the addition of molecular hydrogen, hydration, on the other hand, is the process of the addition of water molecules in a compound.