Desulfurization Of Gasoline Research Articles

Advancing gasoline desulfurization: Multi-objective fuzzy optimization in systems technology

Ultrasonic-assisted oxidative desulfurization (UAOD) is utilized to lessen environmental problems due to sulfur emissions. The process uses immiscible polar solvents and ultrasonic waves to enhance desulfurization efficiency. Prior research focused on comparing the effectiveness of UAOD for gasoline using response surface methodology. This study evaluates the desulfurization efficiency and operating costs, including ultrasonic power, irradiation time, and oxidant amount to determine optimal conditions. The study used a multi-objective fuzzy optimization (MOFO) approach to evaluate the economic viability of UAOD for gasoline. It identified upper and lower boundaries and then optimized the desulfurization efficiency and operating costs while considering uncertainty errors. The fuzzy model employed max-min aggregation to optimize the degree of satisfaction on a scale from 0 (unsatisfied) to 1 (satisfied). Optimal conditions for gasoline UAOD were found at 445.43 W ultrasonic power, 4.74 min irradiation time, and 6.73 mL oxidant, resulting in a 66.79 % satisfaction level. This yielded a 78.64 % desulfurization efficiency (YA) at an operating cost of 13.49 USD/L. Compared to existing literature, gasoline desulfurization was less efficient and less costly. The solutions provided by MOFO demonstrate not only economic viability through decreased overall operating costs and simplified process conditions, but also offer valuable insights for optimizing prospective future industrial-scale UAOD processes.

Desulfurization of Gasoline and Diesel by Fly Ash‐Derived FAU Zeolite

AbstractSulfur in fossil fuels is a major environmental and public health concern worldwide due to emissions of sulfur oxides formed during combustion. This may require new developments or upgrades of existing refining technologies. Hence, further desulfurization of gasoline and diesel to combat hazardous emissions could be a significant step toward environmental protection. In this study, adsorptive desulfurization of gasoline and diesel was achieved using a low‐cost fly ash‐derived faujasite (FAU) zeolite as complementary to the conventional hydrodesulfurization method. Sulfur levels of fuel samples, brought to the laboratory from typical fuel stations, were detected by a turbidimetric method before and after desulfurization. FAU zeolite sorbent, prepared from coal fly ash, was contacted with the fuel samples at stopped flow, and the residual fuels were analyzed to determine the sorbent's desulfurization performance. The process was optimized to enhance the sorbent's performance by varying the reaction conditions such as temperature, fuel volume, and the sorbent chemical composition. The results indicated that, at ambient temperature and pressure, the zeolitic desulfurization could reduce the sulfur content approximately by 40 % of its initial concentration, from 61 to 37 ppm and 155 to 97 ppm, in gasoline and diesel, respectively. Therefore, fly ash zeolites offer a possible opportunity for further desulfurization of refining petroleum fuels which may lead to economic and environmental gains.

Deep oxidative desulfurization of real fuels by a new nanocomposite based on mono Cd(II)‐substituted Keggin‐type silicotungstate, cobalt ferrite and polyaniline as an efficient nanocatalyst

AbstractTo obtain clean fuel, synthesis and characterization of a novel nanocomposite based on mono CdII‐substituted silicotungstate (K3SiW11CdO39), cobalt ferrite (CoFe2O4), and polyaniline (PAN) was presented for the first time. K3SiW11CdO39@CoFe2O4@PAN was identified by FT‐IR, XRD, SEM, and EDX techniques. The outcomes of the characterizations have shown that K3SiW11CdO39 and CoFe2O4 are uniformly dispersed on the PAN surface. The K3SiW11CdO39@CoFe2O4@PAN was employed as a heterogeneous catalyst in the extractive coupled oxidative desulfurization (ECOD) of both real gasoline and dibenzothiophene (DBT) as a thiophenic model fuel. Under relatively mild reaction conditions, the catalytic performance of the as‐prepared nanocatalyst in the ECOD procedure was studied by incorporating acetic acid/hydrogen proxied as an oxidant system at a volume ratio of 1:2. Based on the results, the K3SiW11CdO39@CoFe2O4@PAN nanocatalyst demonstrated effectiveness of up to 95% with 0.1 g at 35°C under optimal operating conditions in the ECOD process. Additionally, the synthesized nanocatalyst exhibited the ability to undergo five consecutive runs in the ECOD process without any discernible reduction in its activity.

Expanded polystyrene waste with Lead-Organic frameworks for adsorptive desulfurization of gasoline

In the current work, a Pb-based metal–organic framework (Pb-MOF) is integrated with expanded polystyrene (EPS) waste for adsorptive desulfurization of dibenzothiophene (DBT) from gasoline. Pb-MOF is synthesized using lead nitrate and 1,4-benzenedicarboxylic acid and incorporated into a clear EPS-tetrahydrofuran solution through ultra-sonication to obtain the Pb-MOF-EPS membrane. The as-prepared Pb-MOF, pristine EPS, and Pb-MOF-EPS membranes are characterized by FTIR, SEM, and EDX. The Pb-MOF-EPS membrane is exposed to 10 ppm DBT solution made in n-hexane, at room temperature as it showed enhanced removal of DBT compared to pristine EPS. Moreover, the Pb-MOF-EPS membrane also demonstrated efficient removal of DBT from commercial gasoline without any sample pre-treatment requirement. The study exhibits that waste EPS can be functionalized with MOFs for adsorptive desulfurization thus, utilizing waste polymer for offering a sustainable and low-cost solution for thiophenes removal.

Ni/ZnO@ZSM-5 Reaction Adsorption Desulfurization Catalyst for Octane Number Improvement

Reaction adsorption desulfurization technology is one of the main means of gasoline desulfurization. In this work, ZnO nanoparticles were prepared by pyrolytic oxidation using ZIF-8 as precursor. ZnO spheres with particle size of 5 nm can be formed after the pyrolysis of Zif-8. Ni/ZnO5nm prepared by equal volume impregnation method can achieve 99.2% desulfurization rate at 390°C, which has more excellent desulfurization performance compared to Ni/ZnO100nm. Ni/ZnO@ZSM-5 was synthesized by in-situ growth-pyrolysis oxidation-equal volume impregnation method. In the reaction adsorption desulfurization process of FCC gasoline, the desulfurization rate reached 99.5%, and the aromatic content in the product increased by 10.7 percentage points, showing excellent octane number improvement. This work provides new ideas for the synthesis of ZnO nanoparticles as well as novel reactive adsorbent desulfurizers, and promotes the development of S-Zorb process.

Reactive adsorption desulfurization of model FCC gasoline on Ni-based adsorbents: Effect of active phase dispersion on activity and HDS/HYD selectivity

A series of Ni/ZnO-Al2O3 and Ni/ZnO-SiO2 adsorptive-catalytic adsorbents differing in the support composition (the Al2O3, SiO2 and ZnO covered) and nickel surface content have been synthesized. Zinc oxide-based supports and Ni supported adsorbents were characterized using X-ray diffraction (XRD), temperature-programmed reduction (TPR), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and N2 physisorption to study their structural properties and morphology. Desulfurization (HDS) and hydrogenation (HYD) activity of the synthesized systems, as well as the HDS/HYD selectivity factor (SF) were determined in the process of reactive adsorption of model FCC gasoline containing thiophene (1000 ppm of sulfur) and 1-hexene (20 wt%) on a fixed-bed flow-type laboratory unit. It has been established that an increase in the nickel surface content and average particle size of the active phase leads to an enhancement of the HDS/HYD selectivity factor regardless of the support used. The Ni/ZnO-SiO2 sample with 8 at Ni/nm2 exhibited the highest HDS/HYD selectivity at a high level of thiophene conversion (> 96%) in the chemisorption mode. The evolution of catalytic properties of Ni-Zn sorbents during FCC gasoline desulfurization process was estimated as well as characteristics of sulfurized samples. Relationships between the turnover frequency number in HDS and HYD reactions, HDS/HYD selectivity factor and size of Ni particles are discussed. DFT calculations of the adsorption thermodynamics were carried out for three model components and adsorption in the diffusion-controlled mode of the feedstock was studied for a series of nickel clusters. The results helped to explain the catalytic behavior of Ni-based sorbents in chemisorption and catalytic (after sulfur saturation) conditions.

Liquid Extraction of Thiophene from n-Paraffins (C8, C10 or C12) Using Two Ionic Solvents [Mebupy][BF4] or [Emim][CH3SO4

Desulfurization of gasoline and diesel models is investigated through liquid–liquid extraction of thiophene (C4H4S) from n-paraffin compounds. Ionic solvents of 4-methyl-N-butylpyridinium tetrafluoroborate [mebupy][BF4] or 1-ethyl-3-methylimidazolium methylsulfate [emim][CH3SO4] as selective solvents have been evaluated at 313.15 K and atmospheric pressure of 101.3 kPa. Experimental liquid–liquid equilibrium (LLE) data for the six ternary systems of n-octane, n-decane, or n-dodecane + thiophene + [mebupy][BF4] or [emim][CH3SO4], were used to calculate the values of the thiophene distribution ratio, selectivity and efficiency of ionic solvents. The experimental data were correlated using the UNIQUAC equations, and the binary interaction parameters have been reported. The phase diagrams for the ternary mixtures including both the experimental and calculated tie lines have been presented.

Reactive adsorption desulfurization of FCC gasoline over self-sulfidation adsorbent

NiSO4/ZnO-Al2O3-SiO2 adsorbent, as a novel reactive adsorption desulfurization (RADS)adsorbent, has self-sulfidation ability and high desulfurization performance when treating model fuel. However, the RADS performance of the adsorbent under FCC gasoline feedstock is not well understood. Here, we compare the performance of the adsorbent under FCC gasoline with model fuel to test the effect of the hydrocarbon composition of the feedstock. The complex composition of FCC gasoline makes it sensitive to the nickel loading amount of the adsorbent. Under the influence of specific surface area and pore structure, the adsorbent loaded with 3 wt% nickel shows better desulfurization activity when treating FCC gasoline. As hydrocarbons in FCC gasoline compete with sulfur compounds for active Ni sites, the reaction conditions have been tested and optimized to achieve deep desulfurization while maintaining low olefin loss to ensure the octane number of the product. By experimental tests and characterization, it has been proved that NiSx and NiO acted as active Ni sites of the adsorbent. Based on these observations, the mechanism of RADS of FCC gasoline over NiSO4/ZnO-Al2O3-SiO2 adsorbent has been proposed, which provides theoretical support for the development of new adsorbents and the optimization of RADS process.

Highly oxidative desulfurization of thiophenic model fuels and real gasoline by Keggin‐type heteropolyanion immobilized on polyaniline and chitosan as an efficient organic–inorganic nanohybrid catalyst

AbstractTo obtain clean gasoline, a new nanohybrid catalyst (TPA@PAN@CH) was synthesized by immobilizing tungstophosphoric acid (TPA) on the surface of polyaniline (PAN) and chitosan (CH) polymers. The features of the materials were detected by FT‐IR, UV/vis, XRD, FE‐SEM, and EDX methods. The XRD patterns demonstrate that the average crystallite size of the TPA@PAN@CH is estimated to be approximately 45 nm, which corresponds to the results of the FE‐SEM. The catalytic performance of the TPA@PAN@CH was tested in the nano‐catalytic oxidative desulfurization (Ncat‐ODS) of gasoline and model fuels by H2O2/AcOH (volume proportion of 2:1) oxidizing agent. The best desulfurization outcomes were achieved by 0.1 g of the TPA@PAN@CH as a nanocatalyst at 35°C under mild reaction conditions. Based upon the above findings, the sulfur content could be declined from 0.4986 to 0.0193 wt%, which corresponds to performance of 96%. Mercaptan concentration decreased from 98 to 4 ppm, and the removal efficiency of model fuels declined in the order of DBT ≥ BT > Th. The high catalytic activity of TPA@PAN@CH was maintained for five cycles without significantly diminishing its performance. This work suggested the potential application of the TPA@PAN@CH for eliminating of hazardous sulfur compounds that significantly affect the efficacy of the Ncat‐ODS.

Catalytic aerobic desulfurization of fuels in the presence of nanosized mixed carbide FeWC

Nanosized mixed tungsten-iron carbide (FeWC) was successfully applied in aerobic oxidative desulfurization. The combination of catalytically active centers responsible for the activation of oxygen and the oxidation of sulfur-containing compounds made it possible to obtain a highly efficient catalyst. The catalyst was synthesized by microwave irradiation, allowing to obtain a nanoscale catalyst in just 15 min. The catalyst was characterized in detail by a variety of methods: XRD, HRTEM, EDX, SEM, XPS, and low-temperature nitrogen adsorption/desorption. The key factors influencing the dibenzothiophene (DBT) oxidation were investigated. Under optimized conditions DBT conversion was 100% in 1 h at 130 °C, 6 atm. The possible mechanisms including oxygen activation, alkyl peroxide formation, and substrate oxidation by tungsten peroxo-complexes were discussed. The catalyst retains its activity for at least 5 cycles of oxidation-regeneration. Aerobic oxidative desulfurization of straight-run gasoline in the presence of FeWC was performed and sulfur content was reduced from 995 to 6 ppm.

Extractive Desulfurization of Liquid Fuel with Three-Body NMP/BEN/H2O Deep Eutectic Solvents

As a new green solvent, deep eutectic solvents (DESs) have been widely studied in the fuel desulfurization industry. This study introduces for the first time a novel three-body DES synthesized from nitromethylpyrrolidone (NMP) as a hydrogen bond acceptor (HBA) and benzoic acid (BEN) and water (H2O) as hydrogen bond donors (HBDs). It is also used for extractive desulfurization (EDS) of model oil and analogue FCC gasoline. A Fourier transform infrared ( FT-IR) spectrometer was used to detect the hydrogen bond relationships among NMP, BEN, and H2O. The changes in viscosity and density of the three-body DESs also indicated the formation of intermolecular hydrogen bonds among the components and indicated the possible binding forms between the three components of DES. Three-body DESs (NMP/BEN/H2O) have higher activity, lower viscosity, and lower volatility than water-deficient two-body DESs (NMP/BEN). By adjusting the mass ratio between the three components and comparing the experimental results of desulfurization, it is shown that the three-body DES (8NMP/2BEN/0.06H2O) containing 6 wt % water has the best desulfurization performance, and its four-stage extractive desulfurization rate for the dibenzothiophene model oil (MO-3) can reach 99.8%. The results of this study may expand the application scope of H2O and provide a new type of DES for extractive desulfurization of fuel oil and other fields.

Extractive Catalytic Oxidative Deoxygenation of Model Fuels Catalyzed by a Vanadium-Substituted Heteropolyacid and Molecular Oxygen

Extractive catalytic oxidative deoxygenation (ECODO) completes extractive catalytic oxidative desulfurization (ECODS) and extractive catalytic oxidative denitrogenation by removing organic oxygen from fuels. This is particularly necessary for renewable fuels to make them more stable and efficient. In ECODO, compounds such as cresol, furan, and their derivatives could be completely oxidized under oxygen at 20 bar and 120 °C using an aqueous heteropolyacid catalyst solution. The oxidation products were separated in situ in the three-phase process, either as CO2 or CO in the gas phase or as water-soluble organic acids like formic and acetic acid as well as acetone. In the case of stable dibenzofuran (DBF), the conversion could be drastically increased from only 27% to above 50% by tuning the reaction conditions and optimizing the catalyst loading by a design of experiment. Moreover, the amount of oxygen in the gas phase could be drastically reduced from 20 to 4 bar operating in 20 bar of synthetic air without limiting the performance of the catalyst. Furthermore, it could be shown that the parallel ECODS in the presence of an oxygenate like DBF leads to better desulfurization of model gasoline than without. The ECODO therefore offers a potential alternative to the classical hydrodeoxygenation, which is not only more energy-efficient but also replaces the expensive hydrogen with cheap air and avoids additional unit operations for fuel cleaning.

An Industrial Data-Based Model to Reduce Octane Number Loss of Refined Gasoline for S Zorb Process

S Zorb process is one of the main technologies for deep desulfurization of gasoline from fluid catalytic cracking (FCC) process, which by the process will also cause some research octane number (RON) loss of gasoline. Establishing a data-driven model with data mining technologies to optimize production is one of the development directions in petrochemical field. Based on the industrial data from a 1.20 Mt/a S Zorb unit in China in recent three years, 422 modeling samples and 22 modeling variables were screened out and then three data-driven models were established by back propagation neural network (BPNN), radial basis function neural network (RBFNN) and generalized regression neural network (GRNN) to predict RON of refined gasoline (r-RON). The results show that the BPNN model has the best prediction effect and generalization ability. Genetic algorithm (GA), particle swarm optimization algorithm (PSO) and simulated annealing algorithm (SA) in combination with the BPNN model respectively were used to optimize the operation variables to reduce the r-RON loss. The results indicate that the optimized performance of PSO-BPNN model is best because of its largest reduction in r-RON loss at 48.55%. The validity of the PSO-BPNN model was verified in the S Zorb unit and the research methods to establish a data-driven model for reducing r-RON loss are also worthy of reference for other S Zorb units.

Oxidative desulfurization with hydrogen peroxide of catalytic cracking and coking gasolines produced from a mixture of Azeri oils

To extract sulfur compounds from oils, hydrogenation processes with a high consumption of hydrogen using expensive platinum catalysts, etc are implemented. In this regard, we have studied the process of oxidative desulfurization of catalytic cracking gasoline (CCG) and coking gasoline (CG) with hydrogen peroxide, as well as their narrow fractions, using cobalt-, molybdenum-containing and iron oxide catalysts with further extraction of sulfur-oxidized compounds with ionic liquids (morpholinium formate). The initial sulfur content in CCG and CG is 397 and 1558 ppm, respectively. After oxidation and extraction with an ionic liquid of oxidized CCG and CG, the sulfur content was 100.4 and 336.4 ppm, respectively. The degree of desulfurization in this case for CCG and CG is equal to 74.7 and 78.4 %, correspondingly. The degree of desulfurization of gasoline fractions ranged from 70 to 85 % with virtually no change in the ON (octane number) of gasoline.

Study on prediction and optimization of gas–solid erosion on S-Zorb reactor distribution plate

Adsorption desulfurization of catalytic gasoline (S Zorb) is an important desulfurization measure that is performed to meet the environmental protection requirements before the final product oil is sold in the market. The desulfurization reactor is a gas–solid two-phase flow environment composed of high-temperature and high-pressure hydrogen-oil mixed gas and sorbent particles; erosion prominently occurs on the reactor distribution plate. This study selects the typical gas–solid two-phase flow conditions and defines the erosion mechanism of the gas–solid two-phase flow environment for the plastic material of E347. Moreover, an S Zorb desulfurization reactor model is constructed, the CFD-DEM model is adopted to predict the wall erosion characteristics in a gas–solid two-phase flow environment, typical erosion laws are obtained via calculations. The erosion laws under the influence of variable parameters are studied based on the orthogonal test, the orthogonal test results show the best parameter combination, the parameter combination yields the maximum erosion rate and high erosion area that are 29.9% and 17.3%, respectively, lower than the existing values. Moreover, an optimum scheme of the inner structure parameters of the reactor is determined for reducing erosion rate and area.

Defect engineering and post-synthetic reduction of Cu based metal–organic frameworks towards efficient adsorption desulfurization

Adsorption desulfurization (ADS) is one of the most potential technologies for desulfurization of gasoline, while developing adsorbents with high sulfur capture capability to meet the strict environmental regulations remains a challenge. Here, a series of CuBDC-x adsorbents containing additional defects and enhanced adsorption sites via modulator-induced defect engineering and subsequent post-synthetic reduction strategy were synthesized. The optimal CuBDC-1 samples showed a remarkable sulfur adsorption capacity of 41.1 mg S/g in model fuel, which is 104.5 % higher than that of original CuBDC. The Cu+ rather than Cu2+ cations in MOFs were found to be the main adsorption sites for mercaptan molecules. This work offers a new insight into developing high-efficiency adsorbent for ultra-deep desulfurization.

Reactivation of the spent Ni/ZnO-based adsorbent with enhanced initial activity for gasoline desulfurization

The widespread application of the S-Zorb technique generates a large quantity of spent Ni/ZnO-based adsorbents which are hazardous wastes. Reactivation and recycling of the spent adsorbents generate huge environmental benefits, which unfortunately has not gained deserved attention. Herein, a modified acid-base coupling method was developed for reactivation of the spent adsorbents. Extra active sites of nickel are introduced into the reactivated adsorbents to improve the initial desulfurization activity. It was carried out by introducing nickel salt into the acid reactivation system followed by the precipitation process during the alkali treatment step. The obtained adsorbents were characterized systematically and the possible reactivation mechanism was disclosed. The newly formed nickel oxides are well dispersed over the reactivated adsorbents and exhibit a strong interaction with support. It favors the increase of hydrogenolysis centers for CS bonds breakage, improving the desulfurization activity. The newly reactivated adsorbent with extra 10 wt% nickel loading shows significantly improved initial desulfurization activity compared with the reactivated adsorbent without extra nickel loading. It even exhibits comparable desulfurization performance to the fresh adsorbent in gasoline desulfurization and the sulfur content in outlet meets the Euro V standard (below 10 μg g−1).

Kinetics and Mechanism of Catalytic Oxidation Desulfurization of Gasoline Liquefied Petroleum Gas in MeroxTM Process with Microfluidics

AbstractCatalytic oxidation desulfurization of gasoline liquefied petroleum gas (LPG) is a key process for the utilization of petroleum hydrocarbons. However, the inherent mechanism remains unclear and the kinetic investigation is usually performed in processes with limited mass transfer rates. Herein, the kinetics and mechanism of catalytic oxidation of sodium ethyl mercaptide were investigated with microfluidics. The effects of temperature, pressure, residence time, and gas‐liquid flow ratio on the oxidation were assessed on the basis of eliminating mass transfer resistance. According to the results of UV‐vis spectra and binding constant, it was confirmed that the catalytic center was in the form of the dimer. A heterogeneous reaction kinetic model was proposed as such. The kinetic parameters close to intrinsic kinetics and corresponding kinetic rate expression were obtained.

Visible Light Induced Ag-Polyoxometalate Coassembly into Single-Cluster Nanowires.

1D superlattices with long-ranged periodicity present extraordinary application properties due to their unique electronic structures. Here, the visible light driven synthesis of 1D single-cluster chains constructed by polyoxometalate (POM) and Ag clusters is reported, where two types of clusters align alternatively along the nanowire. Low symmetrical POM clusters of [P2 W17 O61 ]10- , [P2 W15 O56 ]12- , and [EuW10 O36 ]9- can be used as building blocks. The directly bonding cluster units result in interactive electronic structures of Ag and POM clusters, as well as the greatly promoted electron transfer during the redox reaction. The Ag-P2 W17 nanowires perform significantly enhanced activities in both electrochemical sensing and catalytic gasoline desulfurization compared with individual building blocks, demonstrating the extraordinary application properties and promising potentials of cluster-based heteroconstructions.

The CREC Fluidized Riser Simulator a Unique Tool for Catalytic Process Development

The CREC Riser Simulator is a mini-fluidized bench scale unit invented and implemented in 1992, at the CREC (Chemical Reactor Engineering Centre), University of Western Ontario The CREC Riser Simulator can be operated at short reaction times, in the 3 s to 20 s range. The present review describes and evaluates the original basic concept of the 1992-CREC Riser Simulator Unit, and the improved design of the 2019-CREC Riser Simulator. Both the initial and the enhanced units are specially engineered to allow the rigorous assessment of both catalyst performance and catalytic reaction kinetics. Kinetic parameters of relatively simple and accurate mathematical models can be calculated using experimental data from the CREC Riser Simulator. Since its inception in 1992, the CREC Riser Simulator has been licensed to and manufactured for a significant number of universities and companies around the world. Several examples of scenarios where the CREC Riser Simulator can be employed to develop fluidized bed catalytic and heterogeneous reactor simulations are reported in this review. Among others, they include (a) hydrocarbon catalytic cracking, (b) the catalytic conversion of tar derived biomass chemical species, (c) steam and dry catalytic methane reforming, (d) the catalytic oxydehydrogenation of light paraffins, (e) the catalytic desulfurization of gasoline, and (f) biomass derived syngas combustion via chemical looping. In this review, special emphasis is given to the application of the CREC Riser Simulator to TIPB (tri-iso-propyl-benzene) catalytic cracking and the light paraffins catalytic oxydehydrogenation (PODH).