A. Tota

Theoretical and Experimental Investigation of Concentration and Contact Time Effects in Membrane Reactors

A potential field of applying membrane reactors is the enhancement of selectivity and yields in complex reactions like networks of parallel and series reactions. To evaluate, design and optimise dosing concepts exploiting membranes it is necessary to perform systematic studies. In this paper the possibility of enhancing selectivity and yields by application of optimised dosing concepts is investigated theoretically and experimentally. In the first, the theoretical part of the study presented, dosing of one reactant at discrete reactor positions (cascade of fixed-bed reactors) was compared with continuous dosing through a porous reactor wall (packed-bed membrane reactor). The effects of manipulating the local reactant compositions (and thus the local reaction rates) and the component residence time distributions via the different dosing strategies is elucidated. In the second part of this study, it is illustrated by experimental data from oxidative dehydrogenation of ethane, that membrane reactors possess indeed the potential to improve selectivity and yields of desired intermediates. By application of membrane reactors it is possible to optimise the selectivity for different products in a given reaction network.