Guidelines for the design of efficient sono-microreactors

Abstract

Possible drawbacks of microreactors are inefficient reactant mixing and the clogging of microchannels when solid-forming reactions are carried out or solid (catalysts) suspensions are used. Ultrasonic irradiation has been successfully implemented for solving these problems in microreactor configurations ranging from capillaries immersed in ultrasonic baths to devices with miniaturized piezoelectric transducers. Moving forward in process intensification and sustainable development, the acoustic energy implementation requires a strategy to optimize the microreactor from an ultrasound viewpoint during its design. In this work, we present a simple analytical model that can be used as a guide to achieving a proper acoustic design of stacked microreactors. An example of this methodology was demonstrated through finite element analysis and it was compared with an experimental study found in the literature.

Design and Characterization of a Scaled-up Ultrasonic Flow Reactor

“…In addition to the scale-up of the fluidic part of an ultrasonic reactor, it is also required to characterize the primary and secondary effects of low frequency ultrasound across scales 15,[25][26][27][28] .…”

“…In addition to the scale-up of the fluidic part of an ultrasonic reactor, it is also required to characterize the primary and secondary effects of low frequency ultrasound across scales. ,− To date, there are few studies that have investigated characterization methods of ultrasonic effects in micro and milli-fluidic devices. ,,− The main investigated parameter is the acoustic pressure field distribution. ,,,− This parameter can be characterized by using both experiments and numerical simulation. Hydrophone measurements of the acoustic pressure , and sonochemiluminescence observations, based on the reaction between luminol and hydroxyl radicals formed by ultrasonic cavitation, ,, were carried out by Verhaagen et al for the design and characterization of their cavitation intensification bag setup, which enabled to place the cavitation bag at the most active site in the ultrasonic bath.…”

Continuous Ultrasonic Reactors: Design, Mechanism and Application

“…As the front mass is usually made of a light metal and the back mass a heavy metal, the ultrasound wave is mainly irradiated from the front surface. Sometimes, a sonotrode is connected to the front surface, in order to guide the ultrasound to the working material [103,104]. Langevin-type transducers typically dominate for applications where relatively large reactor volumes and thus high ultrasonic powers are required [105][106][107].…”

“…For this, experimental studies serve as validation for the numerical methods. The most investigated effect of ultrasound by numerical simulation is the acoustic pressure distribution, which can be predicted by solving the Helmholtz equation [104,120,125]. Rossi et al [120] investigated the acoustic wave propagation and attenuation in a PMMA reactor by solving the Helmholtz equation:…”

Sonoelectrochemistry: Ultrasound-assisted Organic Electrosynthesis

“…This field of flow chemistry (in microreactors) has been gaining interest, proving to be a hot topic for science and engineering. , Thus, the amount of research has been increasing so that miniaturized devices have become commercially available from a small-scale for use in laboratories as well as for scaling up for industrial applications, mainly to obtain information on new methods of organic synthesis. − The microreactor technology advantages are mass and heat transfer enhancement, a high surface-to-volume ratio, laminar flow operation, precise residence time control, and short molecular diffusion distances. , Also, this technology results in better yields with higher selectivity due to regular flow settings . These advantages can be applied to a variety of organic synthesis processes, highlighting the integration of organic electrosynthesis with microreactor technology (flow chemistry) and electrodes for reaction performance (electrosynthesis) − and the integration of ultrasound with small-scale flow reactors for organic synthesis. ,− …”