Test Reactions to Study Efficiency of

Abstract

Effects of mixing on the course of fast chemical reactions are relatively well understood, especially in homogeneous systems. This enables to design and operate chemical reactors with the goal to achieve a high yield of a desired product and use systems of complex reactions as a chemical probe (chemical test reactions) to identify progress of mixing and quality of mixture. Recently, a number of studies have focused on the application of chemical test reactions to identify energy efficiency of mixing, being a convenient way of comparing mixers and reactors in terms of their mixing efficiency. This review offers a presentation of chemical test reactions available in the literature and methods of applications of test reactions to identify the energy efficiency of mixing. Also methods to assess the extent of micromixing by measuring product distribution or segregation index, and to determine the time constant for mixing are presented for single phase homogeneous systems and two-phase liquid-liquid systems.

Development of customized 3D printed stainless steel reactors with inline oxygen sensors for aerobic oxidation of Grignard reagents in continuous flow

“…This reduces the problem to a mixing rate limiting case of a homogeneous reaction system, which is well understood even for fast reactions. 35 In passive mixing elements the degree of mixing of homogeneous reaction systems are predefined by the structures themselves and the operation conditions, i.e. inlet flow rates.…”

Mixing Performance Evaluation for Commercially Available Micromixers Using Villermaux–Dushman Reaction Scheme with the Interaction by Exchange with the Mean Model

“…The development of competitive reaction systems for mixing characterization has been dominated by Bourne and Villermaux. Common reaction systems include the Diazo Coupling, Bourne III, Bourne IV, and Villermaux–Dushman reaction systems. ,,− The Villermaux–Dushman system has generally been accepted as the standard for micromixer characterization due to its advantages in terms of in-line analysis by UV spectrophotometry, quantification of mixing times via reaction kinetics, inexpensive reagents, and the ability to adjust the analytical range through the reagent concentrations. ,,, …”

Sucrose solution as a new viscous test fluid with tunable viscosities up to 2 Pas for micromixing characterization by the Villermaux–Dushman reaction

“…The origin of mixing efficiency can be for example the impeller type, the place of injection, the impeller speed or in the case of tubular reactors the type of winding or the type of static mixing elements [3,4]. Moreover, at critical conditions where a thermal runaway is occurring the injection place of a stopper solution must be set in a way that mixing, in this case micromixing, can be achieved as fast as possible.…”