3,4,5-Tri-dodecyloxybenzoic acid: combining reaction engineering and chemistry in the development of an attractive tool to assist scaling up solid-liquid reactions

The synthesis of tris-O-dodecyl-gallic acid (3,4,5-tri-dodecyloxybenzoic acid) was selected as a model system in our program to define design tools and a methodol. for fine-chem. scale-up. The just-suspended conditions of potassium carbonate in MIBK have been studied to find a scale-up rule for this system from 1 dm3 lab-scale to an industrial scale of 6000 dm3. By adjusting the relation of Zwietering to the values obtained by visual observations of the lowest stirrer speed at which the solid particles are just-suspended on a 1- and a 10-dm3 scale with different particle sizes and two stirrer types, a scale-up rule was developed which was verified under just-suspended conditions on a 50-dm3 scale. In addn., a prediction was made using this rule as a min. criterion for a 6000-dm3 reactor where no problems regarding off-bottom criteria are expected. The focused beam rotating measurement (FBRM) and photo video measurement (PVM) Lasentec techniques have been used successfully to det. just-suspended stirrer rates and to gain more insight into the dynamic (de)agglomeration behavior of potassium carbonate during the tri-alkylation of Me gallate. These techniques proved to be powerful tools in accelerating process development of heterogeneous reaction systems. [on SciFinder (R)]