Hydrogenation and dehydrogenation

Hydrogenation and dehydrogenation are the oldest catalytic processes. Catalytic hydrogenation reactions are used for production of fine chemicals, in pharmaceutical industry and polymer industry and for the production of edible and non edible fats and oils. Dehydrogenation reactions are used for production of light alkene C₃-C₄ for preparation of acrylonitrile, oxoalcohols or propylene oxides and production of C₄-C₈ for detergents. The process is also used for preparation of polypropylene, styrene, aldehydes, ketones etc.

Hydrogenation

Some of the hydrogenation processes are:

1.   Hydrogenation of alkenes and alkadienes

Example

a.  hydrogenation of ethene to ethane

• C₂H₄ + H₂ = C₂H₆

b. hydrogenation of cyclohexene to cyclohexane

• C₆H₁₀ + H₂ = C₆H₁₂

2. Hydrogenation of aromatics

Example : Benzene to cyclohexane which is the precursor for nylon polymer.

1. C₆H₆ + 3 H₂ = C₆H₁₂