Formation of Free Sulfur in Hydrodesulfurized Gas Oil—Precautions for Pilot Test of Ultra Deep Hydrodesulfurization Catalysts

Autor: Hiromichi Koshika, Kazuhiro Inamura, Ryuichiro Iwamoto, Nobuyuki Takahashi
Rok vydání: 2005
Předmět:
Zdroj: Journal of the Japan Petroleum Institute. 48:319-323
ISSN: 1349-273X
1346-8804
Popis: Special precautions for evaluating ultra deep gas oil hydrodesulfurization catalysts in the pilot plant were investigated. Analysis using gas chromatograph atomic emission detector (GC-AED) and GC-MS showed free sulfur was formed in the hydrodesulfurized product gas oil, if H 2 S dissolved in the product oil contacted air. Although the precise mechanism of free sulfur formation is not clear, direct oxidation of H 2 S, Claus reaction or the oxidation of ammonium polysulfide are possible routes. Once free sulfur forms in the product gas oil, it is difficult to remove by stripping with nitrogen gas. To prevent the formation of free sulfur compound completely, H 2 S should be separated before contacting air in a pilot plant or in a sampling chamber sealed with nitrogen gas. On the other hand, no free sulfur compound was observed in commercial gas oil, as no contact with air occurs before H 2 S stripping.
Databáze: OpenAIRE