METHOD OF OXIDIZING SULFUR DIOXIDE Russian patent published in 2001 - IPC

FIELD: chemical and other industries, more particularly preparation of sulfuric acid. SUBSTANCE: method comprises oxidizing SO₂-containing gas mixture in two steps on catalyst layers to prepare, prior to last layer of last step, gas mixture containing 0.03-0.06% by volume of SO₂ at least layer inlet temperature of 400-425 C and absorption of SO₃ after each step. Oxidation on last catalyst layer of last step is carried out to SO₂ content in exhaust gases of lower than 0.01 %, oxygen content in gas mixture at least 9.7% by volume. This enables one to attain high degree of conversion without substantial complication of process. EFFECT: more efficient oxidation process. 3 ex