Proceeding from the analysis of physicochemical processes in existing gas-liquid fixed-bed reactors, two new technologies for gas-liquid reactions on a fixed-bed catalyst developed. In the first technology worked out in the Russian Scientific Center "Applied Chemistry", the process is carried out under conditions of the gravitational liquid film flow over the catalyst surface and liquid recycling. In the second process, presaturated one-liquid-flow technology (POLF technology), the reaction is brought about without the presence of the gaseous phase. Only the liquid phase is fed into the reactor, but this liquid is previously saturated with the gas in a special highly intensive device before the reactor. These new technologies allow carrying out reactions with high productivity and process safety at low energy input in the reactor. A comparative analysis of the existing three-phase fixed-bed technologies destined for exothermic reactions follows. (C) 2003 Elsevier B.V. All rights reserved.