Two-Step Electrodialysis Treatment of Monoethanolamine to Remove Heat Stable Salts

• Published in: Russian journal of applied chemistry Vol. 91; no. 4; pp. 602 - 610
• Main Authors: Grushevenko, E. A., Bazhenov, S. D., Vasilevskii, V. P., Novitskii, E. G., Volkov, A. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.04.2018; Springer Nature B.V
• Subjects: Aqueous solutions; Carbon dioxide; Carbonation; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Electrodialysis; Industrial Chemistry/Chemical Engineering; Monoethanolamine (MEA); Processes and Equipment of Chemical Industry
• ISSN: 1070-4272; 1608-3296
• DOI: 10.1134/S1070427218040110

Electrodialysis technology was adapted to removal of heat stable salts from aqueous solutions of alkanolamine absorbents, with monoethanolamine as example. Removal of anions of heat stable salts by electrodialysis from a 30 wt % aqueous solution of monoethanolamine with the degree of carbonation of 0.2 mol of CO 2 per mole of monoethanolamine was studied. The two-step removal of heat stable salts by electrodialysis allows the monoethanolamine loss to be reduced and the concentration of residual CO 2 in the absorbent solution to be decreased. The suggested two-step electrodialysis treatment scheme allows the concentration of heat stable salts to be maintained on the required level from the viewpoint of their corrosion activity, the total volume of the concentrate to be decreased by 50%, and the monoethanolamine loss to be decreased by 30%. The treatment unit with the circulation volume of the monoethanol absorbent of 100 m 3 h –1 was calculated for confirming the efficiency of the two-step electrodialysis treatment scheme. As compared to the one-step electrodialysis treatment scheme, the two-step scheme ensures recovery of 50% of monoethanolamine at the same efficiency of the removal of heat stable salts.