Ignition-Extinction Analysis of Oxidative Coupling of Methane in Laboratory-Scale Reactors

A detailed ignition-extinction analysis of laboratory scale reactors with heat exchange with furnace is provided for the case of single and multiple oxidation reactions. It is shown that the same volume or mass of catalyst packed in tubes of different diameter and/or with different lengths of inert sections could lead to different type of ignition-extinction behavior as well as product distribution. The impact of tube diameter, heat exchange time, and length of inert sections on the ignition-extinction behavior is analyzed with either the space time (flow rate) or the furnace temperature as the parameter that is varied experimentally. While the highly exothermic oxidative coupling of methane is used as an example to illustrate the approach, the results are applicable to laboratory reactors in which catalytic partial oxidations, oxidative dehydrogenations or other exothermic reactions occur. The results of ignition-extinction behavior are used to provide guidelines for the interpretation of data and for the scale-up of such processes.