Adsorptive desulfurization of heavy naphthenic oil: Equilibrium and kinetic studies

Removing sulfur from liquid fuels has become an important issue in a global society. Modulated synthesis is known to improve the crystallinity of materials, ease of handling, control of crystallite size, and degree of aggregation. A group of adsorbents [activated carbon (AC), a novel synthesized Ni-based metal–organic framework (Ni-BDC), and composites of AC@Ni-BDC treated with different concentrations of nitric acid and modulator (formic acid)] were characterized using X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and temperature-programmed desorption (TPD)-pyridine studies. The adsorbents were also evaluated for adsorptive desulfurization. The quantities of both AC and the modulator were observed to influence the nucleation of Ni-BDC, crystallite size, and crystallinity. The adsorption activity of the composite toward thiophene (TH) was the average of the two materials (i.e., AC and Ni-BDC), while the activity doubled toward dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) with respect to the excepted average. The improved activity was attributed to enhanced pore structure, crystallinity, and synergistic effects that produced stronger acidic sites.

Section: Introductionmentioning

confidence: 99%

Modulated Synthesis of a Novel Nickel-Based Metal–Organic Framework Composite Material for the Adsorptive Desulfurization of Liquid Fuels

Mguni

Yao

Ren

et al. 2021

“…Among them, the adsorptive desulfurization (ADS) is more efficient for removal of thiophene and its derivatives compared with the traditional catalytic hydrodesulfurization (HDS). Moreover, the adsorption process can be operated under mild conditions that lower the costs of final products . For ADS, selecting adsorbents with excellent adsorption capacity and high selectivity for thiophene can efficiently increase the desulfurization rate.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the adsorption process can be operated under mild conditions that lower the costs of final products. 5 For ADS, selecting adsorbents with excellent adsorption capacity and high selectivity for thiophene can efficiently increase the desulfurization rate. To date, a variety of adsorbents, such as zeolites, 6,7 carbon-based materials, 8 and mesoporous materials, 9−11 have been studied for the desulfurization of gasoline.…”

Section: Introductionmentioning

confidence: 99%

Screening and Improving Porous Materials for Ultradeep Desulfurization of Gasoline

Yang

Jiafeng

Chen

et al. 2020

Herein, by screening 89 porous materials (metal–organic frameworks and covalent organic frameworks), the ultradeep desulfurization from model gasolines was investigated by the facile adsorptive approach by grand canonical Monte Carlo simulations. The accessible surface area and void fraction ratio of porous materials are of great significance for the ultradeep desulfurization of gasoline. ZnBDC, MOF-70, MOF-69C, UIO-66, Cd3BTB2, ZIF-77, ZIF-69, and ZIF-2 are identified with ultrahigh selectivity for thiophene/n-octane systems at 298 K and 10 kPa. The relationship between the loading amount of thiophene in materials and the difference of isosteric heat of thiophene and n-octane (or benzene) was confirmed. The pressure swing adsorption and temperature swing adsorption are considered to mimic the separation in industrial processes. Functionalization (impregnation) is an efficient route to boost the selectivity of removal of sulfur-containing compounds from gasoline. Adsorption and separation mechanisms for thiophene from gasolines are determined by the composition and inner structure of materials.

“…3 During combustion of fuels, several sulfur compounds are converted to sulfoxides (SO x ), which cause harmful effects on human organisms, animals, and also plants caused by acid rain. 4 In addition, sulfur in the fuel can damage the industrial equipment and cause economic losses. 5 Deep and ultradeep desulfurization of transportation fuels are more significant issues because of high demands for clean fuels in different fuel cells.…”

Section: Introductionmentioning

confidence: 99%

Model Fuel Deep Desulfurization Using Modified 3D Graphenic Adsorbents: Isotherm, Kinetic, and Thermodynamic Study

Sedaghat

Ahadian

Jafarian

et al. 2019

Three-dimensional graphenic adsorbents have been successfully synthesized by hydrothermal reduction and applied for deep removal of dibenzothiophene (DBT) from model fuel. The nanoporous spongelike structure of the graphenic compounds was confirmed using various characterization techniques. Reduced graphene oxide (rGO), carbon black–graphene composite (CB-G), and nickel-impregnated graphene (Ni-G) showed adsorption capacities of 41.8, 46.9, and 43.3 mg of DBT g–1, respectively, and the DBT concentration in the model fuel was diminished to less than 10 ppm. Thermodynamic parameters for the adsorption process evidenced feasible and exothermic adsorption on rGO and CB-G with negative enthalpy changes. Adsorption isotherms for rGO and CB-G were best fitted with the Langmuir isotherm, indicating uniform adsorption sites. On the other hand, the isotherms for Ni-G were best fitted with the Freundlich and Temkin models, showing special active sites. Carbon black intercalation can effectively change the pore dimensions to meso size while maintaining a uniform graphenic morphology, leading to high DBT adsorption capacities.