Extraction of Dibenzothiophenes from Petroleum Feedstocks Using a Ruthenium Complex in Aqueous Solution

Abstract

In an effort to demonstrate that Ru(NH3)5(H2O)2+ can be used to remove dibenzothiophene from hydrotreated petroleum feedstocks, this metal complex was reacted with a variety of thiophenes (Th*), including dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-Me2DBT) to give complexes of the type Ru(NH3)5(Th*)2+. This ability of Ru(NH3)5(H2O)2+ to bind to thiophenes has been used in an extraction process in which a solution of Ru(NH3)5(H2O)2+ in 70% DMF and 30% H2O is contacted with a simulated petroleum feedstock (45% toluene/55% hexanes) containing 400 ppm of DBT. One extraction removes 50% of the DBT from the feedstock phase as Ru(NH3)5(DBT)2+, which is present in the DMF/H2O phase. Five successive extractions reduce the amount of DBT in the simulated feedstock from 400 to 25 ppm. The Ru(NH3)5(H2O)2+ extractant can be regenerated from the Ru(NH3)5(DBT)2+ either by air-oxidation followed by H2-reduction or by displacement of the DBT by adding H2O to the DMF/H2O phase. Extraction of 4,6-Me2DBT from the simulated feedstock using Ru(NH3)5(H2O)2+ in 70% N,N-dimethylacetamide and 30% H2O was less successful as the 4,6-Me2DBT concentration was only reduced from 400 to 340 ppm.

Separation of Organic Nitrogen Compounds by Supported Liquid Membranes Based on Ionic Liquids

“…Generally, hydrodenitrogenation is the most diffi cult hydrogenation reaction because such deep hydrogenation processes have high energy and hydrogen consumption, so other processes are needed. Methods based on solvent extraction method have been proposed 4), 5) with the advantages of low energy cost, elimination of hydrogen usage, retention of the chemical structures of the fuels, and no special equipment requirements 6) . Novel desulfurization processes have been suggested for fuel oils based on photochemical reactions and solvent extraction 7) .…”

Effects of Ionic Liquids and Supports on the Permeation of Organic Nitrogen Compounds through Supported Ionic Liquid Membranes

“…However, Zn-containing 4 ], which was reported to be a suitable solvent for denitrogenation [12], gave high selectivity and a moderate permeation coefficient. This is because the extraction of organic nitrogen compounds was facilitated through the coordination of the organic nitrogen compound to the Zn atom.…”

“…Generally, hydrodenitrogenation is the most difficult hydrogenation reaction because such deep hydrogenation processes have high energy and hydrogen consumption, so other processes are needed. Methods based on solvent extraction have been proposed [4,5] with the advantages of low energy cost, elimination of hydrogen usage, retention of the chemical structures of the fuels, and no special equipment requirements [5]. Recently, desulfurization and denitrogenation have been investigated with solvent extraction [6][7][8] and supported liquid membranes (SLM) [9,10] using ionic liquids.…”

“…The present study examines the effect of hydrophobicity of cation and anion moieties in 1-alkyl-3-methyl imidazolium salts on the permeation of organic nitrogen compounds and selectivity against heptane. 4 ] which were reported to be suitable ionic liquids for denitrogenation [7,12] were also examined. Moreover, as membrane stability depends on the combination of ionic liquids and membrane materials [13], we examined the effect of membrane materials on the permeation.…”

Highly Ordered Mesoporous WO3 with Excellent Catalytic Performance and Reusability for Deep Oxidative Desulfurization

“…However, it is di±cult to remove aromatic compounds containing sulfur such as dibenzothiophene (DBT) and its derivatives, attributing to their steric hindrance, especially 4,6-dimethyl dibenzothiophene (4,6-DMDBT) by the HDS reaction. [7][8][9][10][11][12] Moreover, the HDS process needs harsh conditions such as high temperature, high pressure and a lot of hydrogen uptake.…”