摘要 |
A process is provided for the recovery of sulfur dioxide liberated in the chemical pulping of lignocellulosic material, which comprises (1) collecting sulfur dioxide-containing gas emitted during the pulping and separating it into at least two portions; (2) contacting at least one portion with chlorine gas, thereby forming a gaseous mixture comprising sulfur dioxide and chlorine; (3) effecting reaction of sulfur dioxide, chlorine and water to form hydrochloric acid and sulfuric acid while forming an intimate dispersion in said gaseous mixture of an aqueous solution of hydrochloric acid and sulfuric acid; (4) dissolving said hydrochloric acid and sulfuric acid in said solution; (5) recovering said solution and separating it from substantially sulfur dioxide-free residual gas. |