Processes - Sodium Bisulphite Production

Sulphuric Acid and Oleum Production | Sodium Bisulphite Production

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Sodium Bisulphite is manufactured from a slip stream of sulphur dioxide gas from the sulphuric acid plant which is reacted with sodium hydroxide (caustic soda) solution. The key reactions are as follows:

SO₂ + 2NaOH → Na₂SO₃ + H₂O
(sodium sulphite)

Na₂SO₃ + SO₂ + H₂O → 2NaHSO₃
(sodium bisulphite)

Na₂SO₃ + 0.5O2 → Na₂SO₄
(sodium sulphate side reaction, not desirable)

SO₃ + 2NaOH → Na₂SO₄ + H₂O
(sodium sulphate side reaction, not desirable)

SBS is also produced as a product of our tail gas scrubber, which was installed in early 2008.