1. Industrial demand for process intensification

Progress made since 1990 in basic research and development in chemical and process engineering, in fine analytical scientific instrumentation and in computer tools, has led to a better understanding and modeling of the physico-(bio)chemical phenomena and transfers of extensities (momentum, heat, matter) involved in the various time and space scales of the chemical production chain (from the scale of the molecule, catalytic site or active ingredient, gene or cell factory to the scale of production units and sites) (figure 1 ).