A comparative analysis is made for a monolithic reactor (MR) and a mechanically agitated slurry reactor (MASR) with an active and selective hydrogenation catalyst available, a situation typical to the fine chemicals industry. The MR is shown to be an attractive alternative to the MASR as far as productivity and consumption of energy is considered. A comparison between the MR and the MASR is illustrated with a case of practical interest, the liquid phase hydrogenation of 3-hydroxypropanal to 1,3-propanediol. In result of mathematical modeling of both reactors over a broad range of operating conditions it was found that the MR performed better than the MASR in terms of bath productivity and selectivity.