engleski

Mass transfer coefficients of slug flow in a microreactor

Application of microreactor systems could be the next break through in intensification of chemical and biochemical processes. Common flow regime for organic solvent- aqueous phase two-phase systems is a segmented flow. Internal circulations in segments cause high mass transfer and conversion. In this work analysis of the slug flow in seven systems of organic solvents and aqueous phase was performed. To analyse how slug lengths in tested systems depends on linear velocity and physical and chemical properties of used organic solvents, regression models were proposed. It was shown that models based on linearization of approximation by potentials give low correlation for slug length prediction, however application of essential nonlinear model of multiple layer perceptron (MLP) neural network gives high correlation with R2 = 0.9. General sensitivity analysis was applied for the MLP neural network model which showed the 80 % of variance in slug length for the both phases is accounted by viscosity and density of the organic phases, 10 % is accounted by surface tension of the organic phase, while molecular masses and flow rates each account for 5 %. For defined geometry of microreactor, mass transfer has been determined by carrying out the neutralization experiment with NaOH where acetic acid diffuses from organic phase (hexane) into aqueous phase. Estimated mass transfer coefficients were in the range kLa = 4652 – 19807 h-1.

ression model; mass transfer coefficient; microreactors

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