ABSTRACT Process intensification is an important tool in chemical engineering, transforming current practices and bringing forth new developments in equipment, processing techniques and operational methods. Several unconventional processing techniques rely on alternative forms of energy. In recent years, chemical application of acoustic and microwave irradiation has received increasing attention and widespread research is in progress in these areas. In this work, kinetic studies of D-fructose, 1-phenyl-1,2-propanedione and ethyl pyruvate hydrogenation as well as esterification of propionic acid with ethanol were carried out in the presence and absence of ultrasound. Furthermore, ethyl pyruvate hydrogenation and esterification of propionic acid and ethanol were investigated under microwave and conventional heating, in a single-mode microwave loop reactor setup. The gained knowledge of the effect of acoustic and micro-wave irradiation on heterogeneously catalysed reactions was employed in the development of quantitative kinetic models which describe the observed reaction rates and product distribution, including suppression of catalyst deactivation by acoustic irradiation as well as the effect of the heating and the solvent on the kinetics and enantioselectivity. The alternative energy sources, acoustic and microwave irradiation, were found to be prominent tools of process intensification, since the catalyst activity, durability and selectivity can be significantly improved by means of these avant-garde energy sources. The results are, however, very dependent on the chemical system.
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