sea water BLOWING OUT

TOWER

STEAMING OUT

TOWER

CONDENSER

SEPARATOR

DRYER

SO2 (g)

H2SO4 (aq)

Cl2 (g)

fresh water

sea water

sea water

HBr (aq)

and

H2SO4

Cl2 (g)

steam

Changes pH from approx 8 to 3.5 Chlorine added to displace bromine by redox reaction

BLOWING OUT

TOWER

Cl2 (g) + 2 Br- (aq) 2Cl-

(aq) + Br2 (g)

+ 2e- reduced

- 2e- oxidised

Sulphur dioxide gas injectedBr2 (aq)

+ SO2 (g)

+ H2O (l) 2HBr (aq) + H2SO4 (aq)

injected to produce fine mist of acids

Acid mixture contains about 13 % by mass of bromine as HBr

STEAMING OUT

TOWER

is used to distil the bromine out of the tower

Chlorine added to displace bromine by redox reaction

Cl2 (g) + 2HBr

(aq) Br2 (g)

+ 2HCl (aq)

hot vapour mixture

small xs SO2 added to remove any Cl or Br

hot vapour mixtureCONDENSER

SEPARATOR

DRYER

Br2 (g) + HCl (g) and steam

damp bromine

HCl (aq)

concentrated H2SO4

PURE BROMINE

used to dry the damp bromine

H2SO4 (aq)