Crystallization is a key process for separation and purification. Especially in the pharmaceutical industry the quality of the developed crystals concerning purity, crystal size distribution and mean particle size is of great importance. The particle size influences further handling and determines the solubility of the particle in the human body. If a narrow particle size can be achieved, costs can be reduced in the separation process. In this thesis the continuous crystallization process in a tubular reactor is developed and improved. The main focus lies on the realization of a system to control the multiphase flow in the system and on the production of suitable seeds (Crystals that can induce the process of crystallization) to run the continuous crystallization process in the tubular reactor. Further attention is given to the procedure of sampling and the solubility of the crystals in the solvent, depending on the temperature is analyzed.