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

Abstract

Recebido em 19/8/11; aceito em 7/2/12; publicado na web em 15/6/12 This work examines traditional and new routes for removal of H 2 S and other sulfur compounds from spent sufidic caustic (SSC). SH -(hydrogenosulfide) and S 2-(sulfide) ions were quantitatively oxidized at 25 ºC using H 2 O 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 2 S from diesel samples at 25 o C. SSC treatment via strong basic anion-exchange resins produced the treated caustic solution with the highest free alkalinity.

Study on Haloalkaliphilic Sulfur-Oxidizing Bacterium for Thiosulfate Removal in Treatment of Sulfidic Spent Caustic

“…The experiments were performed by adjusting the temperature (ranging from 25 to 40 °C), pH (8)(9)(10)(11), sodium chloride (0.5-5 % w/v), and sodium thiosulfate (100-750 mM). For the preparation of the mentioned pH range (8, 9, 9.5, 10, 10.5, 11), a set of carbonate buffers containing 2 M Na + was used.…”

“…Spent caustic is one of the most complicated and hazardous wastewaters produced in various gas and oil sweetening processes in refineries and petrochemical plants [3,[6][7][8]. Although characteristics of spent caustics may greatly vary from a refinery to another, these wastewaters are generally studied in three different categories namely sulfidic, phenolic and naphthenic [6,[9][10][11][12].…”

“…Diluted caustic solutions (NaOH, 5-10 % w/w) are usually used for scrubbing hydrocarbon streams to absorb sulfur compounds such as H 2 S and thiols and finally this process results in sulfurcontaining waste water known as sulfidic spent caustic (SSC). This harmful waste has alkalinity over 12, salinity of 5-12 % w/wand high sulfide (HS -and S 2-) level exceeding 2-3 % w/w [8,[13][14][15]. Sulfidic spent caustic may also contain toxic organo-sulfuric compounds such as methanethiol, and aromatic hydrocarbons like benzene [15,16].…”

Comparative study of strong anion exchange hypercrosslinked poly(HEMA-co-EGDMA-co-VBC) and strong anion exchange poly(Styrene-co-EGDMA-co-VBC): Synthesis and characterization

“…Drawback of such ion-exchange resin is that it has limitedhydrophilic character which is in separation application, such resin useful for retention non-polar compound only and have low specific surface area (SSA). Gel-type resin have higher (SSA) (>1000 m 2 /g) [1] 9,10 and macroporous structure have lower than 600 m 2 /g.…”

“…Many studies showed that positive charges in resin have potential to be used in many applications. For example, in sulfur removal, 1 phosphorus removal in wastewater, 2 separation of actinides elements in sediments and biological materials, 3 and even be used to decrease the acid value of crude low-calorie cocoa butter to an acceptable level. 4 Most of the strong anion resins used in the studies is commercially available.…”