This book analyzes conventional fixed-bed reactors such as trickle-bed, bubble (packed) column, and multitubular reactors with regard to process efficiency, design and safety. It is shown that these reactors do not possess any substantial potential for improving industrial processes. Modern concepts in mass transfer, kinetics and process design are applied to process development. In light of the given analysis, new approaches to the development of technologies based on innovative principles are elucidated. For the first time, first-hand knowledge about two-zone model, oscillation theory, map of the energy dissipation is presented in full.