Desulfurization Of Liquid Fuels Research Articles

Desulfurization of liquid fuels using aluminum modified mesoporous adsorbent: towards experimental and kinetic investigations

In this study, a modified mesoporous adsorbent (MSU-S) impregnated by aluminum was used to remove the aromatic sulfur compounds from n-decane as the model fuel. Physical and chemical properties of as-synthesized adsorbent were investigated by XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy) and BET (Brunauer–Emmett–Teller) method. Adsorptive desulfurization of model fuel was studied through batch and continues processes under mild temperature and normal atmospheric pressure. The equilibrium adsorption was modeled by Langmuir, Temkin, and Freundlich and the kinetics of adsorption was studied through first, second and intraparticle diffusion models. It was figured out that Temkin and the pseudo-second-order model were best fitting the adsorption equilibrium and describing the kinetics, respectively.

Sequential desulfurization of thiol compounds containing liquid fuels: Adsorption over Ni-doped carbon beads followed by biodegradation using environmentally isolated Bacillus zhangzhouensis

Desulfurization of liquid fuels over a wide concentration range continues to be challenging. This study recommends a novel hybrid route to efficiently desulfurizing the thiols or organosulfur compounds containing liquid fuels. The tests performed on the dibenzothiophene (DBT) and thiophene (TH) containing n-octane over sulfur concentration range 300–1200 mg/L showed adsorptive desulfurization followed by the bacterial treatment to be efficient in decreasing the concentration level to 3–15 mg/L at 30 °C and 1 atm pressure. Adsorption performed using the Ni nanoparticles-dispersed porous carbon beads of ~ 0.8 mm size was effective at relatively higher concentrations. Upon nearly saturation in the adsorption step, further removal of the thiol compounds to low concentrations was possible by bacterial degradation using Bacillus zhangzhouensis isolated from the wastewater effluent of a petroleum industry. Fresh and spent adsorbents were characterized using various analytical techniques. Bacterial characterization involved the Christian gram staining and 16S rRNA sequencing. The data demonstrate for the first time ~ 99% removal of the thiol compounds, at rates faster than adsorption alone. The proposed sequential approach in this study can be effective in meeting the globally ever increasing stringent regulations for low sulfur content in fuel oils.

Desulfurization of liquid fuels by extraction and sulfoxidation using H2O2 and [CpMo(CO)3R] as catalysts

Efficient and recyclable liquid–liquid extraction and catalytic oxidative desulfurization (ECODS) systems for the removal of refractory sulfur compounds from liquid fuels are reported that use the cyclopentadienyl molybdenum tricarbonyl complexes [CpMo(CO)3Me] (1), [CpMo(CO)3(CH2-pC6H4-CO2Me] (2) and [CpMo(CO)3CH2COOH] (3) as catalyst precursors. An ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was used as both extractant and reaction medium, entrapping the active homogeneous MoVI catalysts that are formed in situ under the operating catalytic conditions (aqueous H2O2 as oxidant, 50 °C). The high sulfoxidation activity of the catalyst formed from 1 was largely responsible for enabling >99% desulfurization within 1 h of a model oil containing 1-benzothiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene (2000 ppm S). The IL/catalyst phase could be repeatedly recycled with no loss of desulfurization efficiency. By sequentially performing extractive desulfurization and ECODS steps, 83–84% sulfur removal was achieved for untreated real diesel and jet fuel samples with initial sulfur contents of ca. 2300 and 1100 ppm, respectively.

Metal‐organic frameworks for highly efficient adsorption of dibenzothiophene from liquid fuels

By taking desulfurization of liquid fuels as a demonstrative example, a bottom‐up selection was performed to find the metal‐organic frameworks (MOF)‐type adsorbents with highly efficient adsorption performance of large molecules. Through carefully analyzing the adsorption mechanism for typical S‐heterocyclic compounds like dibenzothiophene (DBT), PCN‐10 was selected in consideration of the simultaneous inclusion of several kinds of interactions in the framework. Experimental results demonstrate that this MOF exhibits extraordinary high DBT adsorption capacity (75.24 mg S g−1), showing record uptake among all the reported porous materials for the removal of thiophenicsulfur from fuels (below 1000 ppmwS), to the best of our knowledge. Moreover, the removal rate for the low sulfur concentration (50 ppmwS) can reach beyond 99%. This strategy can be conveniently extended to the screening and design of MOFs for the efficient removal of other important large guest molecules. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4491–4496, 2016

Desulfurization of liquid fuels by air assisted peracid oxidation system in the presence of Fe-ZSM-5 catalyst

Catalytic oxidative desulfurization of the model oil or synthetic sulfur oil (SSO) and the different real/industrial industrial oil fractions was investigated using air assisted hydrogen peroxide and formic acid oxidation in the presence of Fe-ZSM-5 as catalyst. The reactivity of the different model sulfur compounds increased in the order of thiophene< dibenzothiophene (BT)<4-methyl dibenzothiophene (4-MDBT). The desulfurization yield in case of the model oil was increased in the presence of Fe-ZSM-5 and the sulfur content of the model oil was reduced from 1275 to less than 50 ppm in 60 min at 60 °C temperature. The catalyst also performed efficiently in ODS of real industrial oil fractions, i.e., untreated naphtha (UN), light gas oil (LGO), cooker derived combined heavy gas oil (HGO) and Athabasca oil sands derived bitumen (At. Bit.), and sulfur removal of 80, 78, 62 and 60% was attained, respectively. Kinetic investigation revealed that the ODS catalyzed by Fe-ZSM-5 followed the first-order kinetics.

Questionable Green Ionic Liquid: Comment on “Extractive Desulfurization of Liquid Fuels by Energy Efficient Green Thiazolium based Ionic Liquids”

Questionable Green Ionic Liquid: Comment on “Extractive Desulfurization of Liquid Fuels by Energy Efficient Green Thiazolium based Ionic Liquids”

Desulfurization of liquid fuels using air-assisted performic acid oxidation and emulsion catalyst

Abstract Catalytic oxidative desulfurization (ODS) of model oil and commercial oil samples was investigated using an air-assisted performic acid oxidation system with a phase transfer or emulsion catalyst comprising a quaternary ammonium salt-based heteropolyoxometalate. Different emulsion catalysts with a Keggin type heteroployoxometalate anion (containing W, Mo, and V) and cetyltrimethylammonium bromide cation were prepared and characterized by X-ray fluorescence, Fourier transform infrared spectroscopy, and scanning electron microscopy. [C16H33N(CH3)3]3[PW9Mo3O40] was the most effective catalyst in the current oxidation system, which reduced the sulfur content of the model oil from 1275 μg/g to 57 μg/g. The reactivity order of different model sulfur compounds was thiophene

Multistage Extractive Desulfurization of Liquid Fuel by Ionic Liquids

Multistage Extractive Desulfurization of Liquid Fuel by Ionic Liquids

Desulfurization of Liquid Fuels by Adsorption on Carbon-Based Sorbents and Ultrasound-Assisted Sorbent Regeneration

Several carbon-based adsorbents, CuCl/AC, PdCl2/AC, and Pd/AC (where AC denotes activated carbon), were studied for desulfurization of a model jet fuel by selective adsorption of thiophenic molecules. Comparisons with gamma-Al2O3 support and desulfurization of a commercial jet fuel were also studied. The results showed that the selective sulfur adsorption capacity of PdCl2 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 pi-complexation sorbents to remove sulfur-containing compounds, i.e., benzothiophene and methylbenzothiophene. Among all the adsorbents studied, PdCl2/AC had the highest capacity for desulfurization. A significant synergistic effect was observed between the carbon substrate and the supported pi-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 % n-octane. 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 degrees C.

Effects of Nitrogen Compounds and Polyaromatic Hydrocarbons on Desulfurization of Liquid Fuels by Adsorption via π-Complexation with Cu(I)Y Zeolite

Organonitrogen compounds are present in commercial fuels after the hydrodenitrogenation process in quantities up to a few hundred ppmw N. Polyaromatic hydrocarbons (PAH) are present in significant quantities (1.4−11 wt %) in transportation fuels depending on both the region and season. In this work, the effect of organonitrogen (quinoline, carbazole) and PAH (naphthalene, fluorene, phenanthrene) compounds on desulfurization by π-complexation with Cu(I)Y zeolite was studied and found to be moderate. The high selectivity for sulfur was not affected because a very low-sulfur fuel ( quinoline ...

Desulfurization of Liquid Fuel via Fractional Evaporation and Subsequent Hydrodesulfurization Upstream a Fuel Cell System

Desulfurization of commercial liquid fuels for fuel cell application is a mandatory process step in a fuel cell system. A new three-step desulfurization process characterized by fractional evaporation and subsequent hydrodesulfurization (HDS) in vaporous phase at moderate conditions (p = 0.4 MPa, T = 300 °C) was experimentally investigated. The results indicate that the fractional distillation reduces the sulfur compounds, above all high boiling sulfur compounds with a low reactivity. The distillate could be desulfurized in gas-phase reaction down to 1 ppm despite moderate reaction conditions. The new process is well-suited for fuel cell application in small scale.

Fluidized bed combustion and desulfurization of a heavy liquid fuel

An experimental and theoretical study on the combustion and desulfurization of liquid fuels in fluidized beds is proposed in the paper. Tests with a high sulfur liquid fuel (Egyptian mazut) have been performed in a bubbling fluidized bed combustor equipped with a special fuel injector at different operating conditions. Limestone is used as sorbent at various Ca/S ratio. The experiments evidenced that efficient combustion and desulfurization can be achieved under operating conditions that maximize the mixing of fuel vapors and bed materials and depress the spontaneous formation of endogenous fuel rich bubbles. A tall bed and high fuel dispersion velocity largely improve the process efficiency. The design and operation of the fuel feeding device also have a key role. The theoretical study was aimed at developing a predictive model for estimating the desulfurization efficiency in a fluidized bed fed with liquid fuels. The model is based on a novel three phases schematization of the bed. It accounts for the mechanism of bubble coalescence, the diffusion between bubbles and the emulsion, the sulfation reaction, the sorbent attrition and elutriation. A macro-kinetics of fuel oxidation is adopted for the prediction of the O 2 partial pressure in the bed. Model results are presented in the paper. The trend and the measured values obtained from the experiments are well predicted by the model, even if some refinements are needed in order to have a very accurate estimation of the sulfur retention.

Deep desulfurization of diesel oil: kinetic studies and process-improvement by the use of a two-phase reactor with pre-saturator

Desulfurization of liquid fuels is usually obtained by heterogeneous catalyzed hydrodesulfurization (HDS). Improvement of this process is needed, particularly with respect to future low residual S-contents of about 10 ppm . Up to now HDS of diesel oil is performed in a trickle bed reactor equipped with an expensive H 2-recycle, although the H 2-supply is far beyond the amount chemically consumed, at least for deep HDS of an already hydrotreated feed. In addition, scale up of trickle bed reactors is in general problematic. In this work kinetic studies and above all a new HDS-concept using a two-phase reactor is presented. Thereby the oil is externally pre-saturated with H 2 and only the liquid phase is passed over the catalytic fixed bed. The H 2-recycle is then redundant, the intrinsic reaction rate can be utilized, and scale-up problems do not occur. In addition, this concept can also be used for HDS of oils with a higher content of sulfur and/or unsaturated hydrocarbons by installing a liquid recycle.