Three-phase fixed-bed reactors are very often encountered in industrial applica-
tions for carrying out different chemical reactions between gaseous and liquid
reactants on porous catalysts, in processes such as, hydrogenation, hydrotreating,
purification, the Fischer–Tropsch synthesis, and in many others. These processes
form the basis for production of a large variety of intermediate and ultimate
products in refinery, bulk and fine chemistry, in manufacture of monomers, sol-
vents, pharmaceuticals, fragrances, fuels, food additives, etc....