The sulfuric acid plant and the sulphonation plant share a common sulfur-melting system. After melting, the sulfur is conveyed by a sulfur pump to the sulfur burner and combusted with dry air. The dry air is dehumidified by 98% sulfuric acid in the drying tower, reaching a dew point of −40 °C; the main blower then delivers it to the sulfur burner for combustion.

After combustion, the SO₂ is converted once through a converter to produce SO₃ gas. The SO₃ is absorbed by 98% sulfuric acid in the primary absorption tower, and the gas leaving the absorber returns for secondary conversion. The heat from the primary conversion is transferred to the gas after secondary conversion, and the overall conversion rate reaches 99.98%. The SO₃ then undergoes secondary absorption, and the off-gas is alkaline-scrubbed in the scrubber before being discharged to the atmosphere. During early start-up, the scrubber runs at full capacity to absorb the relatively large amount of SO₂ generated at initial ignition; under normal operation, compliant discharge is achieved without passing through the scrubber. Under any operating conditions, the off-gas meets the emission standards of all countries.