New strategies for treatment and reuse of spent sulfidic caustic stream from petroleum industry

摘要

This work examines traditional and new routes for removal of H_2S and other sulfur compounds from spent sufidic caustic (SSC). SH- (hydrogenosulfide) and S_(2-) (sulfide) ions were quantitatively oxidized at 25 °C using H_2O_2, NaOCl or a spent sulfochromic mixture. SH-/S_2- ions were also removed via reaction with freshly prepared iron or manganese hydroxides, or after passing the SSC through strong basic anion exchange resins (OH- form). The treated caustic solution, as well as iron/manganese hydroxides, removed H_2S from diesel samples at 25 °C. SSC treatment via strong basic anion-exchange resins produced the treated caustic solution with the highest free alkalinity.