Abstract:

A desalination process with electrodialysis to remove the salt impurities in raffinose extract solution was
introduced and the effects of different operation voltages and flow rates on desalination ratio and energy consumption
were discussed in this study. Results showed that the ratio of desalination increased with increasing voltage from 10 to
20 V to reach a plateau as the voltage was further increased to 30 V, and was inversely correlated with circulation flow rate
in the range of 20–60 L/h. A desalination ratio of 91.2% was obtained after 120 min at a voltage of 25 V and flow rate of
20 L/h with a raffinose recovery of 94.5%. At the same desalination ratio, energy consumption increased with increasing
voltage from 20 to 30 V, and also increased with increasing flow rate in the range of 20–60 L/h. The electrodialysis has the
potential for application in the desalination process for raffinose purification.

Key words: raffinose, electrodialysis, desalination, purification