The development and optimization of chemical processes and synthesis methods, aiming for better environmental sustainability, simplified processing and lower energy and material consumption, is one of the major research areas of Technical Chemistry. This work, which was done at the Institute of Technical and Macromolecular Chemistry of the University of Technology Aachen, belongs to the above described category. It deals with the development of a new continuous process for the Friedel-Crafts-Acylation of aromatic compounds. The basic concept of this process is based on the immobilization of the FC-Catalyst, a Lewis acid, in an ionic liquid (IL) as a stationary phase. A second mobile phase, consisting of super critical carbon dioxide (scCO2), transports the substrates into the stationary phase, where they get in contact with the catalyst and the reaction takes place. The formed products get extracted and carried out of the reactor by the mobile phase. In This way a homogenous, monophase and discontinuous reaction which normally is done in an organic solvent like nitrobenzene, becomes a biphasic continuous reaction which does not need the use of any organic solvent. For this concept many metal salts and compounds, which all have Lewis-acid properties and are all well known as FC-catalysts that can be applied in catalytic quantities, were tested. Also different ionic liquids (IL) were synthesised and tested as stationary phase, different substrates were deployed and the influence of pressure and temperature on the process was observed. The new and remarkable in this work is that the above mentioned tests and examinations all take place in a biphasic system under continuous conditions. This was realized in an apparatus, which was built and developed specially for this work.