Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

The partial oxidation of hydrocarbons is currently the usual method for the industrial production of a variety of important products. Such processes are frequently characterized by low conversions and yields, which are mostly related to mass and heat transfer problems. Due to the reaction conditions, such processes include also important safety risks and are therefore still not sufficiently investigated. To study the influence of the residence time, oxygen concentration, initiator, additives, temperature and pressure on the product selectivity, a modular micro reactor has been developed and constructed, which permits to perform this class of reactions for the first time as a two phase process in a capillary reactor in an especially wide range of residence times, temperatures and pressures. The production of TBHP by partial oxidation of liquid isobutane is an example for the non-catalyzed oxidation of hydrocarbons with oxygen. Flow rates in the range of 15 µL/ min to 188 µL/ min for isobutane and in the range of 0.1 up to 1.5 mL/ min for oxygen were realized, using capillary lengths of up to 100 m. To characterize the two-phase flow inside the reactor, preliminary measurements of the system isobutane - nitrogen were performed in a glass capillary. Since both, initiators and reaction products are sensitive to most metals, the micro reactor and further parts of the lab facility have been coated. To analyze the reaction mixture, a GC/MS - method has been developed. The challenges of the reactor construction and their solutions are discussed.