Question

what is hydrogenation give one reaction what is its industrial applications

Answer 1

when propen reaction with H2/Ni Pt (catalyst) to give propane..
this is industrial reaction..
use the vanaspati ghee

Answer 2

addition of hydrogen to unsaturated hydrocarbon to saturated hydrocarbon in the presence of catalyst like nickel or palladium.
for example
hydrogenation of fats or oils to ghee