• Gases evolved from volcanoes

• Chloride ion in seawater

• Halite (NaCl)

• Sylvite(KCl)

• Carnallite (KMgCl3.6H2O))

Takes place in HCl burner or HCl oven

Adiabatic process

Highly exothermic

Cooled rapidly at 200°C

99% HCl can be produced

Burner acid is produced

Temperature: 2490 °C

Pressure 14 kPa

H2(g) + Cl2(g) → 2HCl(g)

Salt-Sulfuric Acid (Saltcake) Process

NaCl+ H2SO4→HCl+ NaHSO4at 150 °C (1)

NaCl+ NaHSO4→HCl+ Na2SO4at 550-660 ° C (2)

Hargreaves Process

2SO2+O2+2H2O+4NaCl→4HCl+2Na2SO4

From chlorination of aromatic and aliphatic

hydrocarbons

Aromatic hydrocarbon:

Aliphatic hydrocarbon: RH + Cl2→RCl+ HCl

From the Leblanc process

2NaCl+ H2SO4→Na2SO4+ 2HCl

Na2SO4 + CaCO3 + 2 C → Na2CO3 + CaS + 2 CO2