What is hydrogenation? What is its industrial application?

(N/A) Hydrogenation is the chemical process of adding hydrogen to a molecule. In organic chemistry,it typically involves the addition of hydrogen to unsaturated hydrocarbons (containing double or triple bonds) in the presence of catalysts like palladium $(Pd)$ or nickel $(Ni)$ to produce saturated hydrocarbons.
The general reaction is:
$R_2C=CR_2 + H_2 \xrightarrow{Ni \text{ catalyst}} R_2CH-CHR_2$
Its primary industrial application is the hydrogenation of vegetable oils. Vegetable oils contain long chains of unsaturated fatty acids. By hydrogenating these oils in the presence of a nickel catalyst,they are converted into saturated fats,which are solid at room temperature,commonly known as vanaspati ghee (hydrogenated vegetable fat).