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Metal–organic frameworks (MOFs) have attracted considerable attention for selective deep removal of refractory sulfur compounds from fuels. In this work, cobalt-based MOFs (nanocrystals of Co-ZIF-6...

A successful immobilization of 1-octyl-3-methylimidazolium tetrachloroferrates ([Omim][FeCl4]) thin films on a silica gel while remaining its mesoporousity, was accomplished in this work. The developed catalyst was highly active and cost-effective for deep oxidative desulfurization of refractory thiophenic compounds at room temperature utilizing H2O2 oxidation agent. The reaction products were well separated from fuel by the catalyst itself under a beneficial solvent-free condition. The catalyst was characterized applying different analyses of FT-IR, TGA, XRD, SEM, EDS, AFM, N2 adsorption desorption, BET, and BJH. A sufficiently large pore diameter (∼6.2 nm) and high surface area (∼490 m2/g) of the silica gel for supporting the Lewis acidic [Omim][FeCl4] having a proper anion and cation structure, synergistically enabled a high efficient and selective catalyst for removal of refractory thiophenes. The influences of reaction temperature and time, loading amount of ionic liquid (IL), catalyst and oxidant amount as crucial reaction factors were evaluated in order to have a maximum desulfurization yield. Impressively, only a very low IL loading of 5 wt.% on the silica gel support achieved complete elimination of dibenzothiophene at the optimal mild conditions and room temperature. In the presence of a non-sulfur aromatic hydrocarbon beside different thiophenic models, the desulfurization selectivity of [Omim][FeCl4] increased from 0.92 to 0.95 via immobilization on the silica gel support. A significant decline in the IL consumption was verified as another beneficial effect of this immobilization. The catalyst could be easily separated having a capability for 100 % removal of dibenzothiophene after recycling four times. Meanwhile, GC–MS analysis was employed for further founding of the desulfurization pathway.

Fennel is a member of the Umbelliferae family and one of the most important and commonly used medicinal herbs. Because plant cultivar registration and protection is now confined to a small number of morphological features, the adoption of molecular approaches as complementing tools is unavoidable. In this investigation, the researchers employed ten start codon targeted (SCoT) markers to identify and distinctiveness three synthetic fennel cultivars and eight parental ecotypes. Ten SCoT primers obtained a total of 54 amplified fragments, of which 44 were polymorphic. SC14 and SC2 primers with 9 bands had the most bands, whereas SC17 primers with 5 bands had the least bands. SC29, SC31, and SC2 primers have the greatest polymorphic information content (PIC), Resolving Power (RP), and Marking Index (MI). The genetic similarity of the genotypes analyzed using the Jaccard similarity coefficient varied from 0.31 to 0.76, with an average similarity of 0.54. Genotypes were distinct from one another and split into five categories using cluster analysis, the results of primary coordinate analysis (PCoA) corroborated these findings. These markers proved to be valuable tools for identifying and distinctiveness fennel cultivars due to their good separation of cultivars and independence from environmental effects. As a result, the markers utilized in this research are appropriate for distinction fennel cultivars.

Background: As a global health threat, the COVID-19 pandemic has a significant impact on maternity care reception in mothers with high-risk pregnancies. Women with high-risk pregnancies are among the most vulnerable groups that require additional precautionary measures against the spread of Covid-19 plus receiving prenatal care. Due to limited information on the status of prenatal care in women with high-risk pregnancies, a qualitative study was conducted to explore the perceptions and experiences of women with high-risk pregnancy regarding receiving prenatal care reception during the COVID-19 pandemic.Methods: The present qualitative study was conducted on mothers with high-risk pregnancies from September 2020 to March 2021. Purposeful sampling continued until achieving data saturation. Ghaem, Ommolbanin, and Imam Reza (AS) government and educational hospitals in Mashhad served as the research environment. Face-to-face and semi-structured interviews were effective data collection methods. Each interview lasted between 20 to 45 minutes (on average 30). The total number of participants was 31. Data analysis was carried out simultaneously with data collection using the qualitative content analysis method developed by Granheim and Landman (2004).Results: Following data analysis and reduction, eight subcategories and three main categories were identified. These included “Negative psychological responses,” “Thinking-based behavior against double danger,” and” Adjustment of health services in the mutual protection”.Conclusion: Receiving prenatal care in women with high-risk pregnancies is associated with challenges in women in the context of the COVID-19 pandemic. This causes negative psychological responses and affects their health-seeking behaviors. Preventive and supportive care can lead to optimum prenatal care for women with high-risk pregnancies focusing on COVID-19 prevention and minimizing pregnancy risk and complications.

In this work, deep extractive catalytic oxidative desulfurization (ODS) of hydrotreated real diesel fuel was attained using a synthesized catalyst of supported molybdenum oxide on mesoporous silica...

A hydrogen-selective and hydrothermally stable membrane composed of silica-zirconia layer deposited on a modified alumina sub layer was successfully prepared. The composite membrane was used for hydrogen purification from synthesis gas in steam methane reforming process. Silica-zirconia layer was synthesized using the CVD method at 923K and atmospheric pressure while the alumina base layer was prepared via sol-gel procedure. DLS, XRD, SEM/EDX, and BET characterization techniques were used to prove that γ-alumina base and silica-zirconia layer are fabricated successfully. Using the composite membrane, hydrogen selectivity toward other gases has improved significantly. Moreover, H2/CH4, H2/CO, and H2/CO2 selectivity have been increased from 700, 350 and 70 in 5 h CVD synthesized membrane to 1600, 750 and 570 for 12 h CVD synthesized membrane respectively. The synthesized Silica-Zirconia membrane successfully altered gases permeability tendency order from H2 > CH4 > CO2 > CO to H2 > CO2 > CO > CH4 which leads to better separation of the product from methane feed. Finally, hydrothermal stability test demonstrated that permeability loss in silica-zirconia CVD coated membrane for H2 is 45.7% after 48 h, while for silica CVD coated on the modified alumina approaches 92.5%.

Lewis acidic ionic liquid (IL) of 1-octyl-3-methylimidazolium tetrachloroferrates ([Omim]FeCl4) with an interesting structure, was synthesized and introduced as a highly effective catalyst and also as extractive solvent in oxidative desulfurization (ODS) of model and real diesel fuels with H2O2 oxidant. FT-IR, H-NMR and TG-DSC analysis were used for characterization of the prepared ILs. GC-FID, GC-PFPD and GC–MS measurements were also employed to investigate the ODS yields and mechanism. The adequate structure and acidic properties of [Omim]FeCl4 allowed removal of thiophenic compounds with high efficiency in an extraction and then oxidation process. The effects of the major processing variables on ODS performance of [Omim]FeCl4 were studied in detail. At the optimal conditions of VIL/Voil of 1/10, O/S molar ratio of 5, reaction time of 15 min and room temperature, BT and DBT were totally eliminated, and 4,6-DMDBT was removed by 99% from the model diesel. Moreover, [Omim]FeCl4 was able to desulfurize two real diesel fuels containing 590 and 2573 ppmw of sulfur with the efficiency of 85% and 61.2%, respectively, at a short time of 15 min. The experimental results also showed a remarkable selectivity of 0.919 for elimination of thiophenic compounds in competition with non-sulfur aromatic model of 2-methyl naphthalene. [Omim]FeCl4 exhibited an excellent recyclability with no significant decline in activity after use in 7 reaction cycles. An overall mechanism was also suggested for desulfurization by the proposed system.

One of the factors determining drug quality in bitter fennel is the types and quantities of fatty acids stored in the seeds. We measured the fatty acid content of 50 Iranian fennel landraces. Fatty acid concentration of the 50 fennel landraces ranged from 9.5 to 23% of seed mass, and the highest amounts of fatty acid content among the early maturing races belonged to Hamedan and Arak (19.5 and 18.5%, respectively), among the medium maturing races to Marvdasht, Kohn and Meshkin Shahr (23, 20.5 and 19%, respectively), and among the late-maturing races to Sari (21%). The highest fatty acid yields belonged to Fasa (65.3 ml/m2) among the early maturing races, Meshkin Shahr and Moqhan (92.5 and 85.4 ml/m2) among the medium maturing races, and Sari (71.4 ml/m2) among the late-maturing races. The main compositions of fatty acids, measured in twelve of the landraces, were oleic acid (52-64%), linoleic acid (26-39%), palmitic acid (0.3-4.1%), stearic acid (1.3-2.4%), linolenic acid (0.6-3.6%) and myristic acid (0.35-1.07%). It was observed that landraces with high oleic acid content originated from regions with a dry and warm climate, while landraces with high linoleic acid content originated from regions with a humid and cool climate. Understanding relationships between the fatty acid profile and landrace origin climate may improve the efficiency of identifying landraces with specific fennel chemotypes. In conclusion, these results indicate that some of these fennel landraces have the potential to be complementary sources of certain fatty acids, such as oleic and linoleic acids.

Zirconium-modified mesoporous silica (Zr S) was synthesized as a new promising catalyst for the acetylation reaction of glycerol. In the presence of Zr S catalyst, the selectivity to desired products (TAG and DAG) reached 91%, with a complete conversion of glycerol. Moreover, 12-tungstophosphoric acid (H3PW12O40) was immobilized onto Zr S surface, and the effect of acid strength of catalysts on this reaction was investigated by NH3-temperature programmed desorption (NH3-TPD) technique. Synthesized materials were characterized by various analytical techniques: X-ray powder diffraction, scanning electron microscopy, N2 adsorption–desorption, and inductively coupled plasma spectroscopy.

The introduction of an attractive catalyst for deep oxidative desulfurization (ODS) is a key factor in this process development. The combination of phosphomolybdic acid (HPMo) and a metal organic framework (Co-ZIF 67) in this work provided a new solid catalyst (named HPMo@Co-ZIF-67) for the selective and efficient removal of dibezothiophenes (DBTs) from fuels. A facile in situ strategy called battle around ship (BAS) was utilized to encapsulate HPMo active sites into the synthesized Co-ZIF-67 nanocrystals with a large surface area, stable structure, and defected sites. The prepared bimetallic HPMo@Co-ZIF-67 composite was used for the catalytic oxidative desulfurization (ODS) of bulky DBT from model fuel using TBHP oxidant. The successful incorporation of HPMo into Co-ZIF-67 and the suitable structure of the obtained composite have been verified by different characterization methods, including XRD, SEM, TEM, FT-IR, BET, BJH, and N2 adsorption-desorption. The ultra-deep desulfurization efficiency of 98% was obtained at T = 70 °C once 40 wt% HPMo loading was introduced. The synergetic effects of uniformly dispersed unsaturated Co ions and Mo contributed to the high ODS performance of the catalyst. A kinetic study was also undertaken, and a possible mechanism was suggested. The recyclability experiments were performed using the washing and heat treatment of the used catalyst. Only a 5% loss in the catalyst performance appeared after five consecutive ODS cycles. The catalyst structure also remained unchanged after five cycles, and no substantial HPMo leaching was detected during the ODS treatment.

Bimetallic Mo-M (M = Ni, Co, and Zn)/RHY supported catalysts were synthesized for oxidative desulfurization (ODS) of dibenzithiophene (DBT). Recrystallized HY zeolite (RHY) included a superior meso-porous structure (RHY) which is attractive for bulky dibenzothiophene (DBT) elimination. The facilities of M promoters on the Mo/RHY features and activity were investigated. Despite similar ionic radius, different electronegativity of Ni, Co, and Zn transition metals caused to different interaction with Mo and RHY zeolite. The results demonstrated that Ni influenced negatively on dispersion of Mo species over the support, while Co and Zn improved the dispersion. Ni interacted readily with framework Al, leading to extraction of Al, collapse of the zeolite structure, and more octahedral and crystalline Mo species. The formation of MoO3 crystals was inhibited by Zn and Co addition leading to improvement of Mo dispersion. Moreover, Zn- and Co-doped Mo/RHY exhibited higher Lewis acidic sites. The ODS activity decreased in the order of MoZn > MoCo > Mo > MoNi. UV–vis results approved that the most of Mo in the Zn doped sample was non-framework type which can well disperse over the external surface. Meanwhile, Co addition enhanced the tetrahedral Mo species incorporated into the zeolite framework. Allowing more exposed high active Mo species for ODS reaction by Zn promoter, the catalytic performance was boosted. The best catalyst, MoZn/RHY, exhibited 100% DBT removal (t = 30 min, T = 40 °C, catalyst/fuel = 10 g/L, O/S = 10, VSolvent/VOil = 1/2, DBT = 1000 ppm) and a high reusability in 4 consecutive recycles. The highest removal of indole as a nitrogen compound was also achieved by the introduced MoZn/RHY catalyst.

NMP.FeCl 3 (NMP = N-methyl-2-pyrrolidone, C 5 H 9 NO) ionic liquid (IL) was effectively immobilized on γ-Al 2 O 3 as a support and examined in the catalytic oxidative deep desulfurization (ODS) of BT, DBT and 4,6-DMDBT from model oil employing 30 wt.% H 2 O 2 as the oxidant reagent. The supported catalyst was prepared via a simple wet impregnation and the effective immobilization of IL was confirmed by FTIR, SEM, EDS, XRD, BET and BJH analysis. The maximum efficiency of 99% was achieved for ODS of DBT using supported IL at the loading amount of 10 wt.%, H 2 O 2 /sulfur molar ratio of 4, temperature of 40 °C, and duration of 90 min. The use of support material in this study resulted in using a lower amount of IL in ODS process. The ODS reactivity of the thiophenic compounds changed in the order of DBT > 4,6-DMDBT ≫ BT. The catalyst was recycled for several times and showed no significant loss in the activity. Furthermore, based on GC–MS analysis of the products, desulfurization mechanism was surveyed and a reasonable pathway was proposed.

Purpose: Hydroxyurea (HU) is a well-known chemotherapy drug with several side effects which limit its clinical application. This study was conducted to improve its therapeutic efficiency against breast cancer using liposomes as FDA-approved drug carriers. Methods: PEGylated nanoliposomes-containing HU (NL-HU) were made via a thin-film hydration method, and assessed in terms of zeta potential, size, morphology, release, stability, cellular uptake, and cytotoxicity. The particle size and zeta potential of NL-HU were specified by zeta-sizer. The drug release from liposomes was assessed by dialysis diffusion method. Cellular uptake was evaluated by flow cytometry. The cytotoxicity was designated by methyl thiazolyl diphenyl-tetrazolium bromide (MTT) test. Results: The size and zeta value of NL-HU were gotten as 85 nm and -27 mV, respectively. NL-HU were spherical.NL-HU vesicles were detected to be stable for two months. The slow drug release and Weibull kinetic model were obtained. Liposomes considerably enhanced the uptake of HU into BT-474 human breast cancer cells. The cytotoxicity of NL-HU on BT-474 cells was found to be significantly more than that of free HU. Conclusion: The results confirmed these PEGylated nanoliposomes containing drug are potentially suitable against in vitro model of breast cancer.

In vacuum distillation processes, pressure drop per unit of theoretical plate ( Δ p ) is an important parameter because overall pressure drop of distillation column must be lower than one atmosphere ( 0 Δ P 1 a t m . ) . Besides, in hard distillation processes having small relative volatility coefficient ( 1 α i 1.1 ) , minimum number of theoretical plates per unit length ( n m i n ) is another important parameter as total height of distillation column cannot exceed the maximum of technologically attainable height. Moreover, by increasing total height of the column its thermal control will be extremely hard. In this work, an efficient structured packing for hard vacuum distillation processes has been fabricated and also calibrated using the binary mixture of Carbon tetrachloride-Benzene, with very low relative volatility coefficient ( 1.128 α i 1.142 ) . In hard vacuum distillation processes both parameters, Δ p and n m i n , are important. Therefore, the effects of three main variables including reflux volumetric flow rate, the number of distributors within the packed-bed and average height of each element of the structured packing on these parameters have been studied. The best amounts of Δ p and n m i n found to be 1.394 mmHg/tray and 14.2175 tray/m respectively. This vividly indicates that the newly introduced structured packing is appropriate for hard vacuum distillation processes.

Cisplatin is a chemotherapeutic agent used for treating various malignancies. The study aimed to prepare pegylated liposomal cisplatin and evaluate its efficacy against human breast cancer cell line MCF-7. Drug-loaded nanoparticles were synthesized by reverse phase evaporation technique. The study is highlighted by extensive characterization of nanoparticles in terms of nanoparticle morphology, type of drug entrapment, cisplatin retention capability, and cytotoxicity effects. The size, size distribution, and zeta potential of nanodrug were estimated 142 nm, 0.33, and -22 mV, respectively. Drug-loading efficiency was equal to 48% that occurred physically. Furthermore, high retention capability (39% of drug was released after 72 h) with significantly enhanced cytotoxicity of nanodrug (1.75 times more than the standard drug) confirmed the potency of liposomal nanoparticles as proper cisplatin carrier.

Fennel is used for various purposes in medical, cosmetic and food industries and Iran is one of its main producers. In this study agro-morphological and phytochemical diversities of Iranian fennel landraces were assessed. According to phenological properties, Iranian fennels were classified as early, medium and late maturity. Based on two years data, late and medium maturity fennels had the higher amounts of vegetative and reproductive traits. In term of seed yield, medium maturity fennels had a better performance, and in term of essential oil content medium and late maturity fennels had the highest values. With considering essential oil yield the highest values were related to medium and late maturity landraces. According to GCMS analysis, in essential oil of the studied Iranian fennels, trans anethole content ranges from 1.24 to 88.45, methyl chavicole from 0.22 to 59.1, fenchone from 1.22 to 14.74 and limonene from 5.5 to 15.71%. Trans anethole chemotype landraces were belonged to arid areas of eastern Zagros and southern Alborz; methyl chavicole chemotype landraces to humid areas of western Zagros and northern Alborz; fenchone chemotype landraces to late maturity landraces from humid area of northern Alborz; and he highest limonene contents to landraces from areas with mediocre altitude in north of Iran. Based on path analysis, as morphological markers to improve seed yield, negative selection of days to 50% flowering and positive selection of weight of dry biomass, and to improve essential oil contents positive selection of days to 50% flowering severely are highly recommended.

In this investigation, quantitative structure-property relationship (QSPR) modelling of adsorption coefficients of 69 aromatic compounds on multi-wall carbon nanotubes (MWCNTs) was studied using the Monte Carlo method. QSPR models were calculated with CORAL software, and optimal descriptors were calculated with the simplified molecular input line entry system (SMILES) and hydrogen-suppressed molecular graphs (HSGs). The aromatic compound data set was randomly split into training, invisible training, calibration and validation sets. Analysis of three probes of the Monte Carlo optimization with three random splits was done. The results from three random splits displayed robust, very simple, predictable and reliable models for the training, invisible training, calibration and validation sets with a coefficient of determination (r

Introduction: Violence at work is considered an important risk factor worldwide. Nurses due to their presence and practice in treatment centers, direct contact with patients and also many stresses are at risk of various types of violence. Objective: The aim of this study was to determine the incidence of violence against nurses working in educational-medical centers in Rasht city. Methods: This is a descriptive-analytical cross sectional study which its population consists of nurses employed in educational-medical centers in Rasht city and 442 nurses were selected by stratified randomize sampling methods. Data collection instrument was extracted from Nachreiner and Rahmany tools used to survey incidence of violence against nurses in the educational-medical centers in Rasht. The findings were analyzed by descriptive and inferential statistics such as T and Chi square tests. Result: Findings showed that 54.1% and 11.1% of nurses experienced verbal and physical violence respectively. Verbal violence in most cases occurred by visitors and physical violence often occurred by patients and in most cases who did not report violence was because it was considered useless. In addition results indicated a significant relationship between verbal violence and level of education (P= 0.02) and physical violence and work condition (P=0.02) and marital status (P=0.02). Conclusion: Results indicated high frequency of verbal and physical abuse toward nurses in health centers in Rasht and different measures are needed to decrease its incidence.

Oxidative desulfurization of thiophenic sulfur compounds of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) with MoOx/Al2O3 catalyst and H2O2 oxidant has been facilitated and more selective under ultrasonic irradiation. The catalyst with the optimum 10% of Mo loading consisted of isolated tetrahedral molybdenum oxide species based on FTIR analysis. The increase of Mo loading to 15% and 20% caused to generation of polymolybdate and MoO3 crystals which decreased desulfurization activity. Sonication enhanced the apparent reaction rate constants in oxidation of all three sulfur compounds. An increase in the Arrhenius factor (A0), which is the total number of collisions per second, could explain the acceleration in the rate constants by sonication. The apparent activated energy (Ea) of BT oxidation was reduced from 96.6 to 75.3 kJ/mol by using ultrasound. This indicated that ultrasound had also a chemical effect, like a catalytic influence, in the acceleration of BT removal. DBT oxidation was reduced when investigated in the presence of tetralin, naphthalene and 2-methyl naphthalene as the model aromatic compounds of actual light oils. A higher selectivity toward DBT elimination in the presence of aromatics was obtained by sonication when compared with the silent treatment. Ultrasound cleaned the catalyst surface from adsorbed aromatics. On the basis of the obtained results, a mechanistic proposal for this desulfurization was explained. Oxidation was performed by nucleophilic attack of sulfur atom to the molybdenum peroxide species of tetrahedral molybdates, which was more advanced by sonication.

In this research, the effects of process variables on the efficiency and mechanism of dibenzothiophene oxidation in formicacid/H2O2 system for deep desulfurization of a light hydrocarbon model were systematically studied by statistical modelling and optimization using response surface methodology and implementing the central composite design. A quadratic regression model was developed to predict the yield of sulfur oxidation as the model response. The model indicated that temperature was the most significant effective factor and suggested an important interaction between temperature and H2O2/sulfur ratio; at temperatures above 56°C, more excess oxidant was necessary because of instability of active peroxo intermediates and loss of H2O2 due to thermal decomposition. In contrast, the water hindrance effect of H2O2 aqueous solution in desulfurization progress was more significant at temperatures bellow 56°C. In the optimization process, minimizing H2O2/sulfur ratio and catalyst consumption for maximum yield of desulfurization was economically considerable. The optimal condition was obtained at temperature of 57 °C, H2O2/sulfur ratio of 2.5 mol/mol and catalyst dosage of 0.82 mL in 50 mL solution of DBT in n-hexane leading to a maximum oxidation yield of 95% after 1 hour reaction. Good agreement between predicted and experimental results (less than 4% error) was found.

Introduction: Illness, hospitalization and pain are often the first crisis that children are faced with ‎and painful procedure such as IV insertion is inevitable and the most cause of children distress. ‎Therefore proper pain treatment is one of the important goals in hospitalized children. Distraction as ‎a non-medical method is among independent nursing implementation which tends to soothe pain ‎with little cost and is attractive to children.‎ Objective: This study aims to determine the effect of distraction on average heart rate resulting ‎from IV insertion in ‎‏3-6‏‎ year old hospitalized children. ‎ Methods: In this clinical trial study, ‎‏72‏‎ children admitted to emergency ward undergoing IV ‎insertion were randomly divided into two control and experimental groups to determine the effect ‎of distraction. During IV insertion, distraction was done with bubble instrument. ‎ Heart rate was measured and compared three minutes before and after intervention with pulse ox ‎meter.‎ Results: The results showed statistically significant differences in the average heart rate (P< ‎‏0‏‎.‎‏01‏‎) ‎of children in two groups before and after the intervention which shows the effect of distraction.‎ Conclusion: According to the research findings distraction with bubble decreases average heart ‎rate in ‎‏3-6‏‎ year old children and can be used as an effective method in pain control during IV ‎insertion in preschool children.&lrm

An optimal heat recovery network requires optimum values of area and energy targets. Current heat exchanger network targeting methods do not consider the optimal allocation of each stream to shell or tube side of the exchanger during the network cost estimation. Some researchers pre-set the allocation of the streams ahead of targeting [Polley, G. T., & Panjeh Shahi, M. H. (1991). Interfacing heat exchanger network synthesis and detailed heat exchanger design. Transactions of the Institute of Chemical Engineers, 69(Part A), 445–457]. In real design case however, some practical considerations such as fouling and corrosion constrain the allocation of streams. Apart from those, other streams are allowed to be allocated to either tubes or shell. Appropriate allocation of these streams can considerably affect the network cost estimation. This paper introduces a new area-targeting procedure which utilizes the optimal allocation of streams in all enthalpy intervals. The procedure evaluates two possible options for each stream split passing through each exchanger in the spaghetti network. Thus, two different exchanger area requirements can be estimated and the one with less area requirement will be selected. During this evaluation process, the optimal distribution of each stream pressure drop within enthalpy intervals is fully utilized. The proposed targeting procedure is applied on a case study and comparison of the results with previous method (Polley & Panjeh Shahi, 1991) shows reduction of around 18% in the network area. In another case study, the area–energy trade offs using the new procedure shows a reduction of 12.4% in minimum network area requirement and 14.5% in total annual cost. Therefore, the new procedure can considerably alter the area–energy trade offs.

Oxidative desulfurization of thiophenic sulfur compounds of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) with MoOx/Al₂O₃ catalyst and H₂O₂ oxidant has been facilitated and more selective under ultrasonic irradiation. The catalyst with the optimum 10% of Mo loading consisted of isolated tetrahedral molybdenum oxide species based on FTIR analysis. The increase of Mo loading to 15% and 20% caused to generation of polymolybdate and MoO₃ crystals which decreased desulfurization activity. Sonication enhanced the apparent reaction rate constants in oxidation of all three sulfur compounds. An increase in the Arrhenius factor (A0), which is the total number of collisions per second, could explain the acceleration in the rate constants by sonication. The apparent activated energy (Ea) of BT oxidation was reduced from 96.6 to 75.3 kJ/mol by using ultrasound. This indicated that ultrasound had also a chemical effect, like a catalytic influence, in the acceleration of BT removal. DBT oxidation was reduced when investigated in the presence of tetralin, naphthalene and 2-methyl naphthalene as the model aromatic compounds of actual light oils. A higher selectivity toward DBT elimination in the presence of aromatics was obtained by sonication when compared with the silent treatment. Ultrasound cleaned the catalyst surface from adsorbed aromatics. On the basis of the obtained results, a mechanistic proposal for this desulfurization was explained. Oxidation was performed by nucleophilic attack of sulfur atom to the molybdenum peroxide species of tetrahedral molybdates, which was more advanced by sonication.

A new heterogeneous sonocatalytic system consisting of a MoO3/Al2O3 catalyst and H2O2 combined with ultrasonication was studied to improve and accelerate the oxidation of model sulfur compounds of diesel, resulting in a significant enhancement in the process efficiency. The influence of ultrasound on properties, activity and stability of the catalyst was studied in detail by means of GC-FID, PSD, SEM and BET techniques. Above 98% conversion of DBT in model diesel containing 1000 μg/g sulfur was obtained by new ultrasound-assisted desulfurization at H2O2/sulfur molar ratio of 3, temperature of 318 K and catalyst dosage of 30 g/L after 30 min reaction, contrary to the 55% conversion obtained during the silent process. This improvement was considerably affected by operation parameters and catalyst properties. The effects of main process variables were investigated using response surface methodology in silent process compared to ultrasonication. Ultrasound provided a good dispersion of catalyst and oxidant by breakage of hydrogen bonding and deagglomeration of them in the oil phase. Deposition of impurities on the catalyst surface caused a quick deactivation in silent experiments resulting only 5% of DBT oxidation after 6 cycles of silent reaction by recycled catalyst. Above 95% of DBT was oxidized after 6 ultrasound-assisted cycles showing a great improvement in stability by cleaning the surface during ultrasonication. A considerable particle size reduction was also observed after 3 h sonication that could provide more dispersion of catalyst in model fuel.

The mesoporous MoO3/γ-Al2O3 catalyst was prepared by incipient wetness impregnation method aiming to investigate the effect of drying method and molybdenum content on the catalyst property and performance towards the oxidation of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyle dibenzothiophene (4,6-DMDBT) with H2O2 for deep oxidative desulfurization of diesel fuel. The catalyst was characterized by XRD, BET, BJH and SEM method. The catalyst with 10wt.% and 15wt.% Mo content represent same optimum performance for DBT and 4,6-DMDBT removal, but a catalyst with 10wt.% Mo has higher efficiency than 15wt.% Mo for BT conversion. The SEM images show that use of rotary evaporator in drying step reaches a more homogenous impregnation. The oxidation reactivity of different sulfur compounds was studied which followed the order of DBT>4,6-DMDBT>>BT., {"references":["C. Song, X. Ma, \"New design approaches to ultra-clean diesel fuels by\ndeep desulfurization and deep dearomatization,\" Appl. Catal. B, vol. 41,\n2003, pp. 207-238.","R. Wang, G. Zhang, H. Zhao, \"Polyoxometalate as effective catalyst for\nthe deep desulfurization of diesel oil,\" Catal. Today, vol. 149, 2010, pp.\n117-121.","P.D. Filippis, M. Scarsella, N. Verdone, \"Oxidative desulfurization I:\nPeroxiformic acid oxidation of benzothiophene and dibenzothiophene,\"\nInd. Eng. Chem. Res., vol. 49, 2010, pp. 4594-4600.","S. Otsuki, T. Nonaka, N. Takashima, W. Qian, A. Ishihara, T. Imai, T.\nKabe, \"Oxidative Desulfurization of Light Gas Oil and Vacuum Gas Oil\nby Oxidation and Solvent Extraction,\" Energy Fuels, vol. 14, 2000, pp.\n1232-1239.","S. Murata, K. Murata, K. Kidena, M. Nomura, \"A Novel Oxidative\nDesulfurization System for Diesel Fuels with Molecular Oxygen in the\nPresence of Cobalt Catalysts and Aldehydes,\" Energy Fuels, vol. 18,\n2004, pp. 116-121.","D. Wang, E.W. Qian, H. Amano, K. Okata, A. Ishihara, T. Kabe,\n\"Oxidative desulfurization of fuel oil Part I. Oxidation of\ndibenzothiophenes using tert-butyl hydroperoxide,\" Appl. Catal. A, vol.\n253, 2003, pp. 91-99.","A. Ishihara, D. Wang, F. Dumeignil, H. Amano, E.W. Qian, T. Kabe,\n\"Oxidative desulfurization and denitrogenation of a light gas oil using\nan oxidation/adsorption continuous flow process,\" Appl. Catal. A, vol.\n279, 2005, pp. 279-287.","P.D. Filippis, M. Scarsella, \"Oxidative Desulfurization: Oxidation\nReactivity of Sulfur Compounds in Different Organic Matrixes,\" Energy\nFuels, vol. 17, 2003, pp. 1452-1455.","W. Trakarnpruk, K. Rujiraworawut, \"Oxidative desulfurization of Gas\noil by polyoxometalates catalyst,\" Fuel Process Technol, vol. 90 ,2009,\npp. 411-414.\n[10] V. Hulea, F. Fajula, J. Bousquet, \"Mild Oxidation with H2O2 over Ti-\nContaining Molecular Sieves, A very Efficient Method for Removing\nAromatic Sulfur Compounds from Fuels,\" J. Catal. Vol. 198 ,2001, pp.\n179-186.\n[11] A. Chica, A. Corma, M.E. Domine, \"Catalytic oxidative desulfurization\n(ODS) of diesel fuel on a continuous fixed-bed reactor,\" J. Catal., vol.\n242 2006, pp. 299-308.\n[12] Ch. Jin, G. Li, X. Wang, Y. Wang, L. Zhao, D. Sun, \"A titanium\ncontaining micro/mesoporous composite and its catalytic performance\nin oxidative desulfurization,\" Microporous and Mesoporous Materials,\nvol. 111, 2008, pp. 236-242.\n[13] Y. Wang, G. Li, X. Wang, Ch. Jin, Oxidative Desulphurization of 4,6-\nDimethyldibenzothiophene with Hydrogen Peroxide over Ti-HMS,\nEnergy Fuels 21 (2007) 1415-1419.\n[14] V.V.D.N. Prasad, K.E. Jeong, H.G. Chae, C.U. Kim, S.Y. Jeong,\n\"Oxidative desulfurization of 4,6-dimethyl dibenzothiophene and light\ncycle oil over supported molybdenum oxide catalysts,\" Catal. Commun.\nVol. 9, 2008, pp. 1966-1969.\n[15] L.C. Caero, E. Hernandez, F. Pedraza, F. Murrieta, Oxidative\ndesulfurization of synthetic diesel using supported catalysts Part I. Study\nof the operation conditions with a vanadium oxide based catalyst, Catal.\nToday, vol. 107-108, 2005, pp. 564-569.\n[16] X.M. Yan, J.H. Lei, D. Liu, Y.Ch. Wu, L.P. Guo, \"Oxidative\nDesulfurization of Diesel Oil Using Mesoporous Phosphotungstic\nAcid/SiO2 as Catalyst,\" J. Chine. Chem. Soc., vol. 54, 2007, pp. 911-\n916.\n[17] J.L. Garcia-Gutierrez, G.A. Fuentes, M.E. Hernandez-Teran, P. Garcia,\nF. Murrieta Guevara, F. Jimenez-Cruz, \"Ultra-deep oxidative\ndesulfurization of diesel fuel by the Mo/Al2O3-H2O2 system: The effect\nof system parameters on catalytic activity,\" Appl. Catal. A. vol. 334,\n2008, pp. 366-373.\n[18] J.L. Garcia-Gutierrez, G.A. Fuentes, M.E. Hernandez-Teran, \"Ultradeep\noxidative desulfurization of diesel fuel with H2O2 catalyzed under\nmild conditions by polymolybdates supported on Al2O3,\" Appl. Catal.\nA, vol. 305, 2006, pp. 15-20.\n[19] Y. Jia, G. Li, G. Ning,\" Efficient oxidative desulfurization (ODS) of\nmodel fuel with H2O2 catalyzed by MoO3/Al2O3 under mild and solvent\nfree conditions,\" Fuel Process. Technol., vol. 92, 2011, pp. 106-111."]}