Liquid–liquid dispersion in a continuous oscillatory baffled reactor – Application to suspension polymerization

Abstract

Reducing energy costs, improving safety, minimizing waste are the current aims of chemical engineering. Process intensification in fine chemistry has been extensively studied but less work refers to heterogeneous reactions involving two liquid phases. This paper focuses on batch to continuous suspension polymerization transposition and especially on the liquid–liquid dispersion step. The main features of suspension polymerization reaction are based on (i) the initial liquid–liquid dispersion requiring a controlled size and narrow distribution and (ii) on the control of the final particle size during the agglomeration step by avoiding fouling which is a bottleneck for continuous flow. For the continuous transposition, liquid–liquid dispersion and reaction studies are carried out in continuous oscillatory baffled reactor (COBR) which is a multipurpose reactor. Its suitability to overcome the bottlenecks is demonstrated through the investigation of the oscillating and flow conditions or the dispersed phase holdup. A controlled droplet size distribution can be achieved. Oscillation is the main parameter responsible for droplet breakage. The suitable conditions to obtain stable dispersion are determined. For one of the first times, COBR is used for suspension polymerization.