Abstract
The potential application of a DEM cell for the electrolysis of hydrogen bromide in the Ispra Mark 13A process for flue gas desulphurization has been tested in a number of laboratory experiments and in long-duration tests in a bench-scale plant of the process. Satisfactory electrode materials have been found, i.e. Hastelloy C 276 for the cathode and a RuO2 coating on titanium for the anode. Both electrode materials showed a good stability during a 1500 hours experiment. Cell voltage/current density relationships have been determined during bench-scale plant operation. A typical value is 1.5V at a current density of 2.5 kA m−2. It has been shown that in an undivided cell a cathodic back reaction occurs which causes a decrease of the current efficiency. Under normal operation conditions current efficiencies of about 90% are obtained.
A simplified flow model for the DEM cell was developed which is useful in understanding the phenomena which occur during scale-up of the cell. An industrial size installation for the production of 170 kg h−1 of bromine at a current density of 2 kA m−2 was constructed and has been in operation since August 1989.
Similar content being viewed by others
Abbreviations
- a x :
-
thermodynamic activity of the constituentx (mol cm−3)
- C :
-
bromine concentration (mol l−1)
- e z :
-
local current efficiency
- e ov :
-
overall cell efficiency
- E 0a :
-
anodic standard potential (V)
- E 0c :
-
cathodic standard potential (V)
- E ca :
-
equilibrium anode potential (V)
- E ce :
-
equilibrium cathode potential (V)
- F :
-
Faraday number (C mol−1)
- g a :
-
anodic overpotential (V)
- g c :
-
cathodic overpotential (V)
- G :
-
electrolyte flow rate (l h−1)
- i :
-
current density (A m−2)
- K c :
-
cathodic back reaction rate factor (l mol−1)
- L :
-
cell width (m)
- n :
-
number of electrons involved (n=2)
- R :
-
gas constant (J K−1 mol−1)
- R cell :
-
cell resistance (ohm m2)
- R c :
-
circuit resistance (ohm m2)
- w b :
-
local cathodic back reaction rate (mol m−2 h−1)
- w th :
-
local theoretical reaction rate (mol m−2 h−1)
- W th :
-
overall theoretical reaction rate (mol h−1)
- T :
-
temperature (K)
- Z :
-
cell length (m)
References
D. Halstead,The Chemical Engineer 443 (1987) 13.
J. Redman,The Chemical Engineer 453 (1988) 29.
L. Himsl and P. Reichel,VGB Kraftwerkstechnik 68 (1988) 56.
C. E. Jahnig and H. Shaw,J. Air Poll. Control Ass. 31 (1981) 421.
K. Scott, T. Fannon and J. Winnick,J. Electrochem. Soc. 135 (1988) 573.
D. van Velzen, H. Langenkamp and G. F. De Beni, ‘Process for the removal of SO2 from waste gases, producing hydrogen and sulphuric acid; Eur. patent no 0.016290.
D. van Velzen and H. Langenkamp, ‘Ispra Mark 13A, a new process for flue gas desulphurization’, Achema Conference, Frankfurt (1988).
P. J. Fiebelmann and G. H. Schütz,Int. J. Hydrogen Energy 5 (1980) 305.
H. Fees, K. Köster and G. H. Schütz,Int. J. Hydrogen Energy 6 (1981) 377.
D. Hughes,The Chemical Engineer 441 (1987) 17.
D. Pletcher, in ‘Industrial Electrochemistry’ (edited by D. Pletcher), Chapman and Hall, London (1984) Chap. 3, pp. 88–113.
A. J. Scarpellino and G. L. Fisher,J. Electrochem. Soc. 129 (1982), 515–522.
S. TrasattiJ. Electrochem. Soc. 39 (1972) 163.
M. Pourbaix, in ‘Atlas of Electrochemical Equilibria in Aqueous Solutions’, Pergamon Press, London (English edition) Chap. IV, Sect. 12.3, 330.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
van Velzen, D., Langenkamp, H., Moryoussef, A. et al. HBr electrolysis in the Ispara Mark 13A flue gas desulphurization process: electrolysis in a DEM cell. J Appl Electrochem 20, 60–68 (1990). https://doi.org/10.1007/BF01012472
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01012472