THE MYTH OF THE WELL-STIRRED CSTR IN CHEMICAL-INSTABILITY EXPERIMENTS - THE CHLORITE IODIDE REACTION

The chlorite/iodide reaction was studied in a continuously stirred tank reactor (CSTR) using a Pt macroelectrode and a movable Pt microelectrode to measure the spatial and temporal distribution of chemical species. When the system is on the thermodynamic branch near the hysteresis limit, it is found that, even in the vicinity of the rapidly rotating stirrer, there exist pronounced, time-invariant, macroscopic concentration gradients that appear to be linked to the field of turbulent energy dissipation. Evidence is presented for the close coupling between chemical and hydrodynamic modes in the evolution of fluctuations and of macroscopic gradients. © 1990 American Chemical Society.