sea water

1
sea water
BLOWING OUT TOWER
CONDENSER
SEPARATOR
STEAMING OUT TOWER
DRYER
2
Changes pH from approx 8 to 3.5
Chlorine added to displace bromine by redox
reaction
Cl2 (g) 2 Br- (aq)
2Cl- (aq) Br2 (g)
H2SO4 (aq)
2e- reduced
Cl2 (g)
- 2e- oxidised
Sulphur dioxide gas injected
Br2 (aq) SO2 (g) H2O (l)
2HBr (aq) H2SO4 (aq)
sea water
BLOWING OUT TOWER
SO2 (g)
fresh water
injected to produce fine mist of acids
small xs SO2 added to remove any Cl or Br
sea water
hot vapour mixture
HBr (aq) and H2SO4
Acid mixture contains about 13 by mass of
bromine as HBr
Chlorine added to displace bromine by redox
reaction
Cl2 (g)
STEAMING OUT TOWER
Cl2 (g) 2HBr (aq)
Br2 (g) 2HCl (aq)
steam
is used to distil the bromine out of the tower
3
hot vapour mixture
CONDENSER
Br2 (g) HCl (g) and steam
SEPARATOR
HCl (aq)
damp bromine
concentrated H2SO4
DRYER
H2SO4 (aq)
used to dry the damp bromine
PURE BROMINE