Application of parallel test reactions to study micromixing in a co-rotating twin-screw extruder

Laminar mixing of Newtonian and completely miscible liquids was studied experimentally in a co-rotating twin-screw extruder by means of parallel test reactions. The side stream of the concentrated solution of base (limiting reactant) was mixed with the main stream of the diluted pre-mixture of acid and ester. A neutral thickening agent was applied to alter the viscosity of both solutions. The selectivity of the test reactions being related to the course of micromixing was affected by operating conditions, the screw geometry and differences in viscosities of the mixed liquids. An explanation of the observed phenomena was proposed.