Chemical engineering is not a simple application of classical disciplines. In the coming years, it has to take up industrial and economic challenges, and to cope with constraints imposed on processes by their natural and social environment. Engineers are faced with new classes of objects and phenomena requiring novel approaches; promising concepts are emerging which may be adapted to chemical engineering processes. The aim of this paper is to stimulate further discussion and research in these areas. Six main topics are dealt with. • Complex media, description and chemical changes. • Novel concepts and paradigms, especially in the field of non-linear dynamic processes, management of energy supply and creation of entropy, strucutre and organisation of condensed matter. • Processes operation and equipment design; innovations are awaited from new contacting and coupling modes, process integration and synthesis, novel reactors and separation devices, new energy sources and recent developments in process control. • Products and quality control, the challenge being to produce end-use properties at will. • Models and the search for “first principles” of a new kind applicable to complex systems at a higher level of integration. • Data and tools such as sensors, computers and visualization techniques. The classical analysis going from macroscopic down to microscopic scale should be completed by a systems approach integrating phenomena from microscopic up to macroscopic complex systems. In conclusion, tracks are proposed for future research about basic principles which make the core of chemical engineering.