Mixing effect on irreversible second order reaction in batch stirred tank reactor.

Abstract

The mass exchange type "micromixing" model in a flow system is extended to batch mixing rate process accompanying a second-order reaction between miscible reactive fluids A and B. The performance of batch mixing rate process accompanied by reaction and the dimensionless parameter q=krCbolkm are obtained from theoretical analysis of the model. When the value of q becomes less than about 0.1, the mixing effect is negligible on the course of reaction. Through analysis of the mixing characteristics of the model, the mass exchange coefficient km can be correlated with mixing time as follows. Theoretical studies mentioned above are confirmed through experimental studies of the alkaline hydrolysis of ethyl chloroacetate, for which the reaction rate is comparable to the rate of mixing and the infinitely rapid reaction of ammoniumhydroxide and acetic acid. The experimental values of km determined in each experiment show that macromixing due to circulation of the fluid element has a dominant effect on the course of reaction in the experimental condition of 300 < Re < 5000.

Continuous stirred tank coalescence/redispersion reactor: A simulation study

“…Population balance mixing models were derived by Chen [14] for describing micromixing in unsteady state flow reactors in terms of internal age and life expectation distributions, by Takao et al [15] investigating micromixing in batch reactors using an interaction with the mean type model, and by Madras and McCoy [16,17] for turbulent mixing in stirred vessels, characterising the mixing process by the increasing interfacial area between the dispersed and bulk fluid because of fragmentation/coalescence of fluid particles.…”

Liquid‐phase mixing in an unbaffled agitated vessel with an unsteady forward–reverse rotating impeller

“…Then, such an approach yields better knowledge of the design and operation, which is useful for practical construction of a new reactor agitated by the mechanically rotating impeller. To describe the mixing process, it is necessary that the overall evaluation of states within the vessel is addressed to temporal and spatial changes, together with determination of hydrodynamic parameters (Nishimura and Matsubara, 1970;Takao et al ., 1978;Verschuren et al ., 2001).…”

New model of micromixing in chemical reactors. 1. General development and application to a tubular reactor

“…In a number of papers (Miyawaki et al, 1975; Costa and Trevissoi, 1972b;Takao et ai., 1975;Takao et al, 1978;Plasari et al, 1978;Pohorecki and Baldyga, 1977a,b;Pohorecki and Baldyga, 1978) their authors tried to apply classical Corrsin (1964a) and Rosensweig (1964) theories of turbulent mixers for a semiquantitative interpretation of micromixing. However, simplifications involved in Corrsin's and Rosensweig's models may lead to large errors in the case of chemical reactors.…”