Controlling fine particle formation processes using a concentric microreactor

To clarify the mechanism of fine‐particle formation processes in a multilamination type microreactor that proceeds mainly due to molecular‐diffusion‐induced mixing, the relation between the size and distribution, and reaction‐operation condition in experimental and numerical approaches is investigated. For experimental study, a concentric microreactor was used, and titania fine‐particle formation was examined as a model reaction. Based on the hypothesis on the fine‐particle formation mechanism, from the experimental results derived, a relatively simple calculation model was made, and validity demonstrated by showing the coincidence of the calculation results and the experimental results. Also, the calculation model was used to establish a technique for predicting the reactant concentration profiles in the microchannel, particle‐growth rate, number of formed particles, and nucleation region. Thus, the proposed analysis method will be useful as a guideline for designing microreactors to form fine particles, and will provide industrially information. © 2006 American Institute of Chemical Engineers AIChE J, 2007