Browse > Article

Production of Ammonia Water and Sulfuric Acid from Ammonium Sulfate by Electrodialysis with a Bipolar Membrane  

Hwang, Ui-Son (Department of Chemical Engineering, Kongju National University)
Choi, Jae-Hwan (Department of Chemical Engineering, Kongju National University)
Publication Information
Journal of Korean Society of Environmental Engineers / v.27, no.1, 2005 , pp. 36-42 More about this Journal
Abstract
This study examined the feasibility of producing sulfuric acid and ammonia water from ammonium sulfate solution using two-compartment electrodialysis with a bipolar membrane (EDBM). Electrodialysis experiments were carried out with 20 wt% ammonium sulfate at different current densities and sulfuric acid concentrations in a concentrate compartment. The current efficiency increased with the current density from 25 to $100\;mA/cm^2$. Nevertheless, the efficiency was relatively low compared with that of general desalting electrodialysis, owing to the diffusion of sulfuric acid from the concentrate compartment to the diluate. The diffusion rate through the anion exchange membrane increased with the sulfuric acid concentration in the concentrate compartment, which decreased the current efficiency. Conversely, the electrical resistance decreased with increasing current density owing to the Joulian heat generated during water dissociation in the transition region of the bipolar membrane under a high electric field. From the experimental results, we concluded that operating at a higher current density is effective from the perspective of current efficiency and electrical resistance when producing sulfuric acid and ammonia water from ammonium sulfate using a two-compartment EDBM process. Further studies on the effects of increasing the sulfuric acid concentration on current efficiency are required to apply the EDBM process practically.
Keywords
Bopolar Membrane; Water Dissociation; Electrodialysis; Current Density; Current Efficiency;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Harris, D. C., Quantitative chemical analysis (4th Ed.), W.H. Freeman, New York(1995)
2 Mulder, M., Basic principles of membrane technology, Kluwer Academic Publishers, Dordrecht(1996)
3 Pourcelly, G. and Gavach, C, 'Electrodialysis water splitting- Applications of electrodialysis with bipolar membranes (EDBM),' Handbook on bipolar membrane technology, Kemperman, A.J.B.(Ed.), Twente Univ. Press, the Netherlands(2000)
4 Probstein, R. F., Physicochemical hydrodynamics, 2nd Eds., John Wiley & Sons, Inc., New York(1994)
5 Choi, J. H., Transport phenomena in ion-exchange membrane under- and over-limiting current regions, Ph.D Thesis, GIST, Gwangju(2002)
6 Strathmann, H., 'Electrodialysis,' Membrane Handbook, Winston Ho, W.S. and Sirkar K.K.(Eds.), Van Nostrand Reinhold, New York, pp. 217(1992)
7 Choi, J. H., and Moon, S. H., 'Structural change of ion-exchange membrane surfaces under high electric fields and its effects on membrane properties,' J. Colloid Interface Sci., 265, pp. 93(2003)
8 Strathmann, H., Krol, J. J., Rapp, H. J., and Eigenber-ger, G., 'Limitting current density and water dissociation in bipolar membranes,' J. Membr. Sci., 125, pp. 123(1997)
9 Baker, R. W., Membrane technology and applications, McGraw-Hill(2000)
10 최재환,'전기투석을 이용한 RO 농축수의 농축', 대한환경공학회지, 26, pp. 410 (2004)
11 Moore, W. J., Physical chemistry, Prentice Hall, Inc., New Jersey(1972)
12 Kang, M. S., Water-splitting phenomena and applications in ion-exchange membranes, Ph.D Thesis, GIST, Gwangju(2003)