Diseño y construcción de un electrodializador a escala de laboratorio para la separación del ácido láctico

Abstract

Electrodialysis is a technique used to separate ions from liquid solutions. In the process, membranes with positive fixed charges let anions pass and membranes with fixed negative charges let the cations pass when an electric field is applied. In this way some liquid streams can be diluted in ions as other liquid streams are concentrated in ions and a separation is achieved. In the Laboratorio de Mezclado, Separacion y Sintesis Industrial (LMSSI) a small pilot module of the K’elf type has been used to separate salts and lactic acid from lactoserum and model solutions presenting a low efficiency of separation. Because of this, a new electrodialysis pilot was designed and constructed which enhances the efficiency if compared with the K’elf model. This is achieved mainly because there is an increase in fluid velocity, which reduces the polarization layer and enhances the mass transfer, as results show: the removal of lactic acid is 26.3% in the K’elf model vs 74% in the equipment built in the LMSSI. The new equipment obtains results closer to the industrial scale equipment, fact that permits a better prediction of the industrial behavior of the fluids treated.