Date of Award

Spring 2009

Document Type

Thesis

Degree Name

Master of Science in Pharmaceutical Engineering - (M.S.)

Department

Chemical, Biological and Pharmaceutical Engineering

First Advisor

Piero M. Armenante

Second Advisor

Laurent Simon

Third Advisor

S. Mitra

Abstract

In this work, a novel continuous flow apparatus featuring the impingement of fluid jet streams in the presence of ultrasonic energy provided by an ultrasonic probe was tested using competitive reactions in order to determine its mixing effectiveness. The ultrasonic energy enhances micromixing of the fluid jet streams, which results in an overall mixing effectiveness improvements in different physical and chemical processes.

In the competitive reactions system used here (third Bourne reaction), one stream containing sodium hydroxide was continuously fed to the first impinging jet, while an aqueous solution of hydrochloric acid and ethyl chloroacetate was fed to the second jet. The concentration of ethanol in the final solution was experimentally determined by gas chromatography (GC) to determine the mixing efficiency: higher ethanol concentrations implied poorer mixing. In all experiments, the volumetric flow rate of sodium hydroxide solution was always kept the same, while the flow rate of the other solution was changed. The sonication power was also varied.

It was experimentally found here that improved mixing was achieved by increasing volumetric flow rate with or without sonication. If sonication was applied, mixing also improved significantly and it was further improved when a higher sonication power was applied. This trend was especially evident at lower flow rates. At high flow rate, sonication played a smaller role. A quantitative comparison of the results based on the use of the Damköhler number is provided.

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