Utilisation of on-line acoustic irradiation as a means to counter-effect catalyst deactivation in heterogeneous catalysis.

The effect of power ultrasound has been studied in the hydrogenation of 1-phenyl-1,2-propanedione (enantioselective hydrogenation) and linoleic acid (fat hardening). Furthermore the hydrogenation of d-xylose to xylitol and citral to citronellal and citronellol were studied under the influence of acoustic irradiation. We have investigated the effect of on-line acoustic irradiation of these heterogeneously catalysed liquid-gas-solid systems in which it was found to counter-effect catalyst deactivation, increase the reaction velocity and to enhance the selectivity of various heterogeneously catalysed reactions.