Selective Adsorption of Sulfur Compounds:  Isotherms, Heats, and Relationship between Adsorption from Vapor and Liquid Solution

Ma, Liping; Yang, Ralph T.

doi:10.1021/ie0700516

Cited by 31 publications

(27 citation statements)

References 41 publications

(115 reference statements)

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“…Recently, they also reported that cation-exchanged Y zeolites (Cu, Ni, Zn, Pd and Ce) are effective for the adsorption of sulfur . Zeolites such as 13X have also been reported to be effective for the removal of sulfur compounds in fuels Ma and Yang 2007a;Salem and Hamid 1997).…”

Section: Introductionmentioning

confidence: 99%

Production of low sulfur diesel fuel via adsorption: an equilibrium and kinetic study on the adsorption of dibenzothiophene onto NaY zeolite

Jianzhun

2010

Adsorption

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The adsorption of dibenzothiophene (DBT) in hexadecane onto NaY zeolite has been studied by performing equilibrium and kinetic adsorption experiments. The influence of several variables such as contact time, initial concentration of DBT and temperature on the adsorption has been investigated. The results show that the isothermal equilibrium can be represented by the Langmuir equation. The maximum adsorption capacity at different temperatures and the corresponding Langmuir constant (K L ) have been deduced. The thermodynamic parameters ( G 0 , H 0 , S 0 ) for the adsorption of DBT have also been calculated from the temperature dependence of K L using the van't Hoff equation. The value of H 0 , S 0 are found to be −30.3 kJ mol −1 and −33.2 J mol −1 K −1 respectively. The adsorption is spontaneous and exothermic. The kinetics for the adsorption process can be described by either the Langmuir model or a pseudo-second-order model. It is found that the adsorption capacity and the initial rate of adsorption are dependent on contact time, temperature and the initial DBT concentration. The low apparent activation energy (12.4 kJ mol −1 ) indicates that adsorption has a low potential barrier suggesting a mass transfer controlled process. In addition, the competitive adsorption between DBT, naphthalene and quinoline on NaY was also investigated. NomenclatureDBT dibenzothiophene t contact time, min c 0 initial concentration of adsorbate in the solution, mmol L −1 c t the concentration of adsorbate at contact time t, mmol L −1 c e equilibrium concentration of adsorbate in the solution, mmol L −1 c DBT the concentration of DBT, mmol L −1 k 0 temperature independent factor, g mmol −1 min −1 k 2 pseudo-second-order rate constant, g mmol −1 min −1 k ads adsorptive constant, L g −1 min −1 k d desorptive constant, mmol g −1 min −1 K L Langmuir constant, L mmol −1 q e adsorptive amount of adsorbate after equilibrium, mmol g −1 q L a solution of the second-order polynomial expression, mmol g −1 q m adsorptive amount of adsorbate to its maximum, mmol g −1 q t adsorptive amount of adsorbate at time t, mmol g −1 θ dimensionless ratio of coverage of the surface of adsorbent v 0 initial adsorptive rate, mmol g −1 min −1 v ads rate of adsorption, mmol g −1 min −1 v d rate of desorption, mmol g −1 min −1 v t rate of adsorption at time t, mmol g −1 min −1 V the volume of solution, L W the mass of adsorbent, g R 2 regression coefficient E a activation energy of adsorption, kJ mol −1 550 Adsorption (2010) 16: 549-558 R g the universal gas constant, 8.314 J mol −1 K −1 T temperature,°C T K temperature in Kelvin, K G 0 Gibbs free energy, kJ mol −1 H 0 enthalpy, kJ mol −1 S 0 entropy, J mol −1 K −1

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Section: Introductionmentioning

confidence: 99%

Production of low sulfur diesel fuel via adsorption: an equilibrium and kinetic study on the adsorption of dibenzothiophene onto NaY zeolite

Jianzhun

2010

Adsorption

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“…The shape of an isotherm provides significant information on the adsorption process (Giles et al 1960). The nature and the strength of the interaction between adsorbate and adsorbent are related to the affinity parameter calculated from the isotherm models (Ma and Yang 2007).…”

Section: Introductionmentioning

confidence: 99%

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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“…It was found that Cu + and Ag + in Y zeolite exhibited high adsorption capacity and selectivity by via π-complexation adsorption with thiophenic compounds. The results also showed the adsorption capacity decreases as follows: Cu + > Ag + > Ni 2+ > Zn 2+ , and the selectivity of adsorption from liquid solutions is in the order of thiophene (TP) < dibenzothiophene < 2-methylbenzothiophene < benzothiophene (BT) for Cu(I)-FAU zeolite. , Hernández-Maldonado et al studied the adsorption properties of X and Y zeolites ion-exchanged with different metallic cations for sulfides in transport fuel oils. Yang and co-workers also studied the adsorption of thiophene and benzothiophene by Cu(I)-modified Y zeolite at normal temperature and pressure.…”

Section: Introductionmentioning

confidence: 99%

“…The results also showed the adsorption capacity decreases as follows: Cu + > Ag + > Ni 2+ > Zn 2+ , and the selectivity of adsorption from liquid solutions is in the order of thiophene (TP) < dibenzothiophene < 2-methylbenzothiophene < benzothiophene (BT) for Cu(I)-FAU zeolite. , Hernández-Maldonado et al studied the adsorption properties of X and Y zeolites ion-exchanged with different metallic cations for sulfides in transport fuel oils. Yang and co-workers also studied the adsorption of thiophene and benzothiophene by Cu(I)-modified Y zeolite at normal temperature and pressure. The results showed that the maximum adsorption capacity for thiophene was 12.8 mg/g and the maximum adsorption capacity for benzothiophene was 38.4 mg/g (the results are summarized in Table ).…”

Section: Introductionmentioning

confidence: 99%

“…16,17 Hernańdez-Maldonado et al 18 studied the adsorption properties of X and Y zeolites ion-exchanged with different metallic cations for sulfides in transport fuel oils. Yang and co-workers 16 also studied the adsorption of thiophene and benzothiophene by Cu(I)-modified Y zeolite at normal temperature and pressure. The results showed that the maximum adsorption capacity for thiophene was 12.8 mg/g and the maximum adsorption capacity for benzothiophene was 38.4 mg/g (the results are summarized in Table 1).…”

Section: Introductionmentioning

confidence: 99%

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Stability Improvement of FAU Zeolites Ion-Exchanged with Copper–Ammonia Solution for the Removal of Thiophene and Benzothiophene from Model Fuel

Cui

Wang

et al. 2019

J. Chem. Eng. Data

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Faujasite (FAU) zeolites with low Si/Al ratios (e.g., X-type zeolites) have much more exchangeable cation sites than those with high Si/Al ratios (Y-type zeolites) for Cu(I), which could improve the adsorption performance via π-complexation. However, the structure of Cu-exchanged X-type zeolites was unstable during autoreduction at high temperatures as reported [ Takahashi Takahashi Ind. Eng. Chem. Res.et. al.20024124872496]. Here, we proposed a scheme of Cu-exchanged X-type zeolites in copper–ammonia solution to improve the stability of the zeolite structure during autoreduction. Therefore, it makes us be able to study the adsorption properties of thiophenic compounds in Cu(I)-exchanged FAU zeolites from low to high Si/Al ratios. The modified zeolites were characterized by X-ray diffraction, high-resolution transmission electron microscopy, inductively coupled plasma spectroscopy, X-ray fluorescence, and Brunauer–Emmett–Teller analysis and tested by adsorption desulfurization experiments in model fuels. The results indicate that the modified zeolites with various Si/Al ratios show different adsorption properties for thiophene and benzothiophene. The adsorption capacity for thiophene decreased in the order Cu(I)Y-5.30 > Cu(I)X-1.23 > Cu(I)Y-2.30. For benzothiophene, the adsorption capacity decreased in the order Cu(I)Y-2.30 > Cu(I)Y-5.30 > Cu(I)X-1.23.

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Selective Adsorption of Sulfur Compounds: Isotherms, Heats, and Relationship between Adsorption from Vapor and Liquid Solution

Cited by 31 publications

References 41 publications

Production of low sulfur diesel fuel via adsorption: an equilibrium and kinetic study on the adsorption of dibenzothiophene onto NaY zeolite

Production of low sulfur diesel fuel via adsorption: an equilibrium and kinetic study on the adsorption of dibenzothiophene onto NaY zeolite

Fixed bed adsorption of benzothiophene over zeolites with faujasite structure

Stability Improvement of FAU Zeolites Ion-Exchanged with Copper–Ammonia Solution for the Removal of Thiophene and Benzothiophene from Model Fuel

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