(83c) Precipitation of Barium Sulphate in a Hollow Fibers Membrane Device – Numerical Simulation and Experimental Validation

Precipitation of barium sulphate in a hollow fibers membrane device involves the permeation of KSO4 through the membrane pores to react with BaCl2 flowing in the lumen side. In this paper, the numerical simulation of barium sulphate precipitation in a hollow fibers membrane device is obtained from the Navier-Stokes equations, transport equations for the chemical species and moments of the crystal size distribution (CSD). The numerical simulations allow the determination of the number-averaged particle size, the coefficient of variation of the CSD, the particles flux, as well as the chemical conversion of the product. The effect of the reactants concentration (5-100 mol m-3), the mean velocity at the inlet of the lumen side (0.025-0.2 m s-1), the inner radius of the hollow fiber (10-3 - 10-4 m), and its length (0.1-0.4 m), on barium sulphate precipitation are investigated. The numerical simulations show that narrow and long hollow fibers allow obtaining high particle fluxes and high chemical conversions. Narrow hollow fibers are advised to obtain low coefficients of variation of the CSD, and short hollow fibers to obtain small averaged particles size. For practical applications, a hollow fibers membrane device should be chosen according to these various criteria. Moreover, experimental measurements of barium sulphate precipitation in a hollow fibers membrane device are realized, and scanning electron microscopy is used to determine the crystal size. It is shown that experimental data compared well with model predictions.