Sulfur organic compounds, removal

Chianelli (85). The resulting effect of this assumption is that the catalysts with the lowest heat of formation are the most active. They also used this model through theoretical calculations to study the promotion effect and fovmd that sulfur removal is favored by Co or Ni (87). However, this model is controversial since too weak sulfur bond strength would probably create anionic vacancies vmable to bond sulfur organic compounds in an efficient way. 

Nitric acid is a strong monobasic acid, a powerful oxidising agent, and nitrates many organic compounds. Until the end of the nineteenth century, it was made by heating a metallic nitrate salt with less volatile concentrated sulfuric acid. Removal of the volatile nitric acid permits the reaction to go to completion. This method is still used for laboratory preparation of the acid. 

Table 3. Sulfur Removal from Organic Compounds by Hydrotreating...

Impurities in bromine may be deterrnined quantitatively (54). Weighing the residue after evaporation of a bromine sample yields the total nonvolatile matter. After removing the bromine, chloride ion may be deterrnined by titration with mercuric nitrate, and iodide ion by titration with thiosulfate water and organic compounds may be detected by infrared spectroscopy sulfur may be deterrnined turbidimetricaHy as barium sulfate and heavy metals may be deterrnined colorimetricaHy after conversion to sulfides. 

Bromine is used as an analytical reagent to determine the amount of unsaturation in organic compounds because carbon—carbon double bonds add bromine quantitatively, and for phenols which add bromine in the ortho and para positions. Standard bromine is added in excess and the amount unreacted is deterrnined by an indirect iodine titration. Bromine is also used to oxidize several elements, such as T1(I) to T1(III). Excess bromine is removed by adding phenol. Bromine plus an acid, such as nitric and/or hydrochloric, provides an oxidizing acid mixture usefiil in dissolving metal or mineral samples prior to analysis for sulfur. 

Caustic soda by reaction of sodium amalgam and water Nitration of organic compounds with aqueous nitric acid Formation of soaps by action of aqueous alkahes on fats or fatty acids Sulfur removal from petroleum fractious by aqueous ethauolamiues Treating of petroleum products with sulfuric acid... 

Boron, D. J. Atlas, R. M. Johnson, A. R., et ah, Method for removing organic sulfur from heterocyclic sulfur containing organic compounds. Patent No. USH1986H. 

Deep desulfurization method of fossil fuels, comprising a first step of HDS and a BDS step for the removal of HDS sulfur refractory compounds, using an effective amount of a biocatalyst. The fuel is incubated in the presence of one or more BDS-active microorganisms, which converts the organic sulfur compounds into water-soluble inorganic sulfur. Then, in a separation stage, the products of the incubation are separated into a deeply desulfurized liquid fossil fuel, and the water-soluble inorganic sulfur. 

Hiperion A process for removing hydrogen sulfide and organic sulfur compounds from hydrocarbons. Similar to the Takahax process but using a solution of chelated iron and naphthaquinone. The elemental sulfur produced is removed by filtration. Licensed by Ultrasystems, CA. 

LO-CAT A process for removing hydrogen sulfide and organic sulfur compounds from petroleum fractions by air oxidation in a cyclic catalytic process similar to the Stretford process. The aqueous solution contains iron, two proprietary chelating agents, a biocide, and a surfactant the formulation is known as ARI-310. The sulfur product is removed as a slurry. Developed in 1972 by Air Resources (now ARI Technologies) and first commercialized in 1976. Over 125 units were operating in 1996. An improved version, LO-CAT II, was announced in 1991. 

---