University of Limerick
Browse

Influence of agitation on primary nucleation in stirred tank crystallizers

Download (1.39 MB)
journal contribution
posted on 2016-11-15, 14:40 authored by Jin Liu, Michael Svärd, Åke C. Rasmuson
The influence of agitation on nucleation of butyl paraben and m-hydroxybenzoic acid polymorphs has been investigated through 330 cooling crystallization experiments. The induction time has been measured at different supersaturations and temperatures in three parallel jacketed vessels equipped with different overhead stirring agitators. In each case, the nucleating polymorph of m-hydroxybenzoic acid has been identified by infrared spectroscopy. The influences of agitation rate, impeller type, impeller diameter, impeller to bottom clearance, and the use of baffles have been investigated. A general trend in all of the experiments is that the induction time decreases with increasing agitation rate. Across all experiments with different fluid mechanics for the butyl paraben system, the induction time is correlated to the average energy dissipation rate raised to the power -0.3. It is shown that this dependence is consistent with a turbulent flow enhanced cluster coalescence mechanism. In experiments with m-hydroxybenzoic acid, the metastable form II was always obtained at higher nucleation driving force while both polymorphs were obtained at lower driving force. In the latter case, form I was obtained in the majority of experiments at low agitation rate (100 rpm) while form II was obtained in all experiments at higher agitation rate (>= 300 rpm).

Funding

PHILIP KAARET / UNIVERSITY OF IOWA FOSSIL JETS FROM BLACK HOLE TRANSIENTS RECENT XMM-NEWTON OBSERVATIONS HAVE LED TO THE DISCOVERY OF A LARGE SCALE X-RAY JET FROM THE LONG-TERM X-RAY TRANSIENT AND BLACK HOLE CANDIDATE 4U 175533. WE OBTAINED A FOLLOW-UP OB

National Aeronautics and Space Administration

Find out more...

History

Publication

Crystal Growth and Design;15 (9), pp. 4177-4184

Publisher

American Chemical Society

Note

peer-reviewed

Other Funding information

Swedish Research Council, SFI

Rights

© Year ACS This document is the Accepted Manuscript version of a Published Work that appeared in final form in Crystal Growth and Design, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/cg501791q

Language

English

Usage metrics

    University of Limerick

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC