Deep desulfurization by selective adsorption of dibenzothiophenes on Ag+/SBA-15 and Ag+/SiO2

McKinley, Scott G.; Angelici, Robert J.

doi:10.1039/b309249f

Cited by 127 publications

(84 citation statements)

References 21 publications

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“…Various types of adsorbents have been used in desulphurization processes, for instance, mixed metal oxides, activated carbon, hydrotalcites, zeolites, aluminophosphates and some novel mesoporous materials (Kim et al 2006;Salem and Hamid 1997;Nemeth et al 1994;McKinley and Angelici 2003;. π complexation adsorbents based on Y zeolite exchanged with Cu (I) and Ag have been developed by Yang and coworkers and used as selective adsorbents in gas oil desulphurization (Hernández-Maldonado et al 2004b).…”

Section: Introductionmentioning

confidence: 98%

Fixed bed adsorption of benzothiophene over zeolites with faujasite structure

2007

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This work addresses the adsorption of benzothiophene (BT), as a model heterocyclic and aromatic sulphur compound present in road fuels, over agglomerated zeolites with faujasite structure. Several adsorbents based on zeolites with FAU structure have been prepared with different Si/Al molar ratios and exchange cations and then agglomerated. The influence of the zeolite basicity has been studied, both in equilibrium and dynamic liquid phase adsorption experiments. Basicity of the adsorbent increased as the Si/Al molar ratio and the electronegativity of the exchange cation decreased. In equilibrium experiments, the affinity towards the adsorbent increased as the Si/Al molar ratio decreased, showing the highest affinity for exchanged low silica X zeolites with medium basicity (A-KLSX-02). Dynamic experiments showed that the less zeolite basicity, the higher fractional bed utilization and adsorption capacity at breakthrough time. Besides, zeolites with high basicity did not reach the equilibrium capacity due to the low diffusivity of BT into the micropores. Thermogravimetric analyses of the spent adsorbents showed a stronger BT adsorption onto the more basic zeolites. As main conclusion, adsorbents with medium basicity could present the best performance in fuel desulphurization due to their high affinity with sulphur compounds, although diffusion problems should be taken into account.

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Section: Introductionmentioning

confidence: 98%

Fixed bed adsorption of benzothiophene over zeolites with faujasite structure

2007

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“…Knowledge of the structure, energy, and geometry of the adsorption complex helps to predict the pathway of the photocatalytic reaction. However, experimental determination of the physicochemical properties of the adsorption complex of sulfur aromatic compounds with the solid sorbent [118] or catalyst [119] is usually quite difficult. [32] Scheme 5 shows the known geometries of thiophene in organometallic compounds; [120] such compounds serve as the "model materials systems" for mechanistic studies of adsorption and catalysis.…”

Section: Adsorption Complexes Of Sulfur Aromatic Compoundsmentioning

confidence: 99%

Heterogeneous Photocatalytic Reactions of Sulfur Aromatic Compounds

Samokhvalov¹

2011

ChemPhysChem

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Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed.

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“…1 A great deal of attention has been paid to developing new approaches to ultra deep desulfurization of liquid hydrocarbon fuels worldwide. [2][3][4][5][6] Selective adsorption is of particular interest. Various types of adsorbents such as mixed metal oxides, active carbon, clays, zeolites and some novel mesoporous materials have been studied.…”

Section: Section 2: Selective Adsorption Of Sulfur Compounds: Isothermentioning

confidence: 99%

“…3 There has been much recent interest in developing sorbents for selective desulfurization. [4][5][6][7][8][9] We have recently developed a class of sorbents that rely on π-complexation bonding to selectively remove organosulfur molecules from commercial fuels. [10][11][12][13][14][15][16] These sorbents were prepared by using several ion-exchange techniques to introduce d-block metals into zeolites, including Ag These ion-exchanged materials are capable of producing fuels with a total sulfur concentration of less than 1 ppmw.…”

Section: Introductionmentioning

confidence: 99%

Adsorption and Ultrasound-Assisted Sorbent Regeneration

Wang¹,

Ma²,

Yang³

2006

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This work was conducted for the department of Energy. In this work, we developed a class of new sorbents that were highly sulfur sepective and had high sulfur capacities. The study consisted of two sections. Development of the new sorbents is described in Section 1, and Section was a fundamental study, conducted for a better understanding for desulfurization of jet fuels. More details of the results are given blow separately for the two sections. Section 1: Desulfurization of Model Jet Fuels by Adsorption on Carbon-based Sorbents and Ultrasound-Assisted Sorbent RegenerationSeveral high-sulfur-capacity carbon-based adsorbents, CuCl/AC, PdCl 2 /AC, and Pd/AC (where AC denotes activated carbon), were studied for desulfurization of a model jet fuel by selective adsorption of thiophenic molecules. The model jet fuel (150 ppmw-S BT and 250 ppmw-S MBT in 19.75 wt% benzene + 80 wt% n-octane containing 700 ppmw naphthalene) was formulated such that it represented all jet fuels well. In addition, a commercial jet fuel, JP-5 was included in the tests. Comparisons with γ-Al 2 O 3 support and desulfurization of a commercial jet fuel were also studied. The results showed that the selective sulfur adsorption capacity of PdCl 2 was higher than that of CuCl and Pd 0 , in agreement with molecular orbital results. It was also found that the activated carbon is the best support for π-complexation sorbents to remove sulfur-containing compounds, i.e. benzothiophene and methylbenzothiophene. Among all the adsorbents studied, PdCl 2 /AC had the highest capacity for desulfurization. A significant synergistic effect was 3 observed between the carbon substrate and the supported π-complexation sorbent, and this effect was explained by a geometric effect. The saturated sorbent was regenerated by desorption assisted by ultrasound with a solvent of 30 wt% benzene and 70 wt% noctane. The results showed that the amount of sulfur desorbed was higher with ultrasound, 65 wt% desorption vs. 45 wt% without ultrasound in a static system at 50 o C. Section 2: Selective Adsorption of Sulfur Compounds: Isotherms, Heats and Relationship between Adsorption from Vapor and Liquid SolutionThis was a basic study in order to understand and better design sorbents for desulfurization of jet fuels. Adsorption isotherms were measured for thiophenic sulfur compounds, thiophene (T), benzothiopnene (BT), 2-methyl benzothiophene (2-MBT) and dibenzothiophene (DBT), from their binary solutions in n-octane. Two sulfur-selective, π-complexation sorbents were studied: Cu(I)-Y zeolite and PdCl 2 impregnated on activated carbon (PdCl 2 /AC). Vapor-phase isotherms of n-octane and thiophene were also measured. The selectivity of adsorption from liquid solutions followed the order of: T < BT < 2-MBT < DBT for PdCl 2 /AC, and T < DBT < 2-MBT < BT for Cu(I)-Y zeolite. The adsorption bond energies, which approximate the heats of vapor-phase adsorption, followed the order: T < BT < 2-MBT < DBT. This order was not followed for adsorption from liquid solutions on Cu-Y zeolite...

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Deep desulfurization by selective adsorption of dibenzothiophenes on Ag+/SBA-15 and Ag+/SiO2

Abstract: Silver (Ag+) salts adsorbed on amorphous silica or mesoporous SBA-15 extract dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-Me2DBT) from simulated, hydrotreated petroleum feedstocks.

Cited by 127 publications

References 21 publications

Fixed bed adsorption of benzothiophene over zeolites with faujasite structure

Fixed bed adsorption of benzothiophene over zeolites with faujasite structure

Heterogeneous Photocatalytic Reactions of Sulfur Aromatic Compounds

Adsorption and Ultrasound-Assisted Sorbent Regeneration

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