Trickle bed reactors are widely used in the petroleum industry, especially when processing heavy petroleum fractions, some of the applications being the hydrodesulfurization and hy-drocracking of heavy or residual petroleum fractions, hydrotreat-hg of lubricating oils, and other hydrogenation processes. In the chemical process industry the use of trickle bed reactors is not so widespread, although reactions such as the selective hydrogenation of acetylene, hydrogenation of alkyl anthraquinone, synthesis of butynediol, and oxidation of liquids with, air or oxygen are carried out. Extensive analysis of the advantages and disadvantages of this type of reactor has been presented in the literature [1–5].