The role of internal diffusion in the hydrogenation of butanal, 2-methylpropanal and 2-ethylhex-2-enal in autoclave on a copper catalyst

The rate of hydrogenation of butanal, 2-methylpropanal and 2-ethylhex-2-ena l was studied on a copper catalyst in the shape of tablets and Raschig ring s at 100 to 160 degrees C and 7 MPa was studied. It was found that the reac tion is strongly affected by internal diffusion since the catalyst particle s with a larger external surface (Raschig rings) were markedly more active. A first-order rate law with respect to the hydrogenated aldehydes has been confirmed.