(Elsevier, 2021) Schuur, Boelo; Gössi, Angelo; Riedl, Wolfgang
Countercurrent membrane supported reactive extraction (MSRE) was studied for removal of carboxylic
acids from aqueous streams with a PTFE capillary membrane. Analysis of the mass transfer rates was per-
formed to support modeling of the process. Total mass transfer coefficients ranging from 2.0 10-7 to
4.0 10-7 m/s were obtained when extracting lactic acid with 20 wt% tri-N-octyl amine in 1-decanol with
membrane thicknesses of 260 mm and 80 mm. The limiting mass transfer resistance in all experiments was
in the membrane phase. The developed model based on mass transfer and reaction in parallel allows to
predict countercurrent extraction. Experimental validation with 5, 7 and 12 m long membrane modules
showed excellent accordance for two acids, validating the model simulations. Simulated membrane con-
tactor lengths required for single, two and three countercurrent stages varied between 10 and 39 m/stage
for lactic, mandelic, succinic, itaconic and citric acid, depending on acid, membrane, and diluent.