Consequences of viscous solutions on the reaction rate with rotating bed reactors
Log-log plot of how viscosity affects the reaction time for a mass transfer limited reaction at a fixed rotational speed of a rotating bed reactor (RBR). The RBR behaved very predictably and delivered reaction times that increased linearly with reaction media viscosity up to at least 500 mPa·s.
Conditions: Time for neutralization of sodium hydroxide (2 M, 50 µL) by acidic cation exchanger (Amberlite IRN 99, 20 mL) packed into a SpinChem® RBR S311 rotated at 500 rpm within a SpinChem® V311 flower baffled reaction vessel containing 500 mL solution consisting of 0-90% glycerol in water to adjust viscosity. The reaction was followed at two different temperatures (10 °C and 30 °C). Neutralization time was determined manually with 3-9 repeated measurements per viscosity using phenolphthalein (10 mg) as indicator. Viscosity was taken as standard tabulated values from J.B. Segur et al. in Ind. Eng. Chem 43 (1951) 2117. Median relative standard deviations of reaction time was 5.3% but had a tendency to increase at the highest viscosities.