Photochemical Production of Biphenyls from Oxidized Sulfur Compounds Obtained by Oxidative Desulfurization of Light Oils

Abstract

Photochemical production and recovery process of biphenyls from the desulfurization products, obtained by oxidative desulfurization (ODS) of light oils, has been investigated. The S-oxidized dibenzothiophenes (DBT sulfones), when dissolved in 2-propanol, were converted successfully into the corresponding biphenyls by photoirradiation at wavelengths of λ > 280 nm using a highpressure mercury lamp, under conditions of nitrogen atmosphere and at room temperature. The present photochemical process was found to be also effective for the production of biphenyls from the DBT sulfones present in the desulfurization products of low-aromatic-content light oils. The quantitative recovery of biphenyls from the resulting 2-propanol solution was carried out successfully by adsorption using neutral aluminum oxide and subsequent elution with dichloromethane/n-hexane (20/80 v/v) mixture.

Desulfurization of Vacuum Gas Oil Based on Chemical Oxidation Followed by Liquid−Liquid Extraction

“…The latter sulfur compounds fraction was analyzed using FI-MS (JEOL JMS-AX505H) to determine the concentrations of individual sulfur-containing compounds in VGO , …”

Post-functionalization of dibenzothiophene to functionalized biphenyls via a photoinduced thia-Baeyer-Villiger oxidation

“…The photochemical behavior of DBTO and the corresponding sulfone DBTO 2 has been investigated extensively 34 . The seminal work of Jenks [35][36][37][38][39] , Greer 40,41 , Nakai 42 , Shiraishi 43,44 , and others 45 has provided important mechanistic insights and enabled the establishment of a general reaction framework that rationalizes the formation of various products observed during photochemical processes involving these compounds. In all cases, it has been established that irradiation of DBTO results in cleavage of the sulfoxide S-O bond to release sulfide DBT and atomic oxygen O( 3 P), which oxidizes the solvent.…”

Photocatalytic oxidative desulfurization of dibenzothiophene by C/TiO2@MCM-41 nanoparticles under visible light and mild conditions

“…TBOT as a precursor. The CTM-41 composites with two different molar ratios of Si/Ti (5,50) were synthesized. The amount of 1.5 g of calcined MCM-41 was placed in a 100 mL round-bottom ask with 50 mL of dried hexane.…”

“…Based on the literature, 48,49 the DBT (1) can be converted to DBT sulfone (2) in the presence of OHc and it is shown in Scheme 2. Shiraishi et al 50 reported that when DBT sulfone was dissolved in 2-propanol and photo irradiated at l > 280 nm by a high-pressure mercury lamp under air, the concentration of DBT sulfone decreases with time and the biphenyl concentration increased. In this work, as is shown in Scheme 2, rst DBT (1) can convert to DBT sulfone (2) in the presence of OHc and then DBT sulfone (2) is photoexcited by photo irradiation to form highly reactive 1,5-biradical (3) intermediate and then it is hydrogenated by OH groups of CTM-41 and further decomposed to form nally biphenyl (5).…”