Today is a time of major changes in the chemical industries in Europe and world wide. The experts of the "Solids Processing Industrial Network" (SPIN) expect that the future will see two kinds of chemical plants: on one hand multipurpose, modular plants and on the other hand world-scale plants. At the same time the already high percentage of solids in the chemical processes is going to increase. This will generate new challenges for the chemical engineering community: Small-scale production of custom-tailored products on the one hand and scale-up of new technologies to size previously unknown to the chemical industries.