Hydro-liquefaction of asphaltene catalyzed by molybdenum-nickel bimetallic catalysts in slurry bed

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mengde Wu ◽  
Guangci Li ◽  
Mohong Lu ◽  
Mingshi Li ◽  
Xuebing Li ◽  
...  
Keyword(s):  
Liquid Fuel ◽  
Catalyst System ◽  
Caproic Acid ◽  
Catalytic Performance ◽  
Active Species ◽  
Mass Ratio ◽  
Fuel Component ◽  
Coke Content ◽  
Bimetal Catalyst ◽  
Dialkyl Dithiophosphate

Abstract The aim of this study is to achieve the hydro-liquefaction of asphaltene for the production of liquid fuel. The oil soluble molybdenum catalysts, molybdenum dialkyl dithiophosphate, and nickel carboxylate precursor with different carbon chains, were synthesized. The catalysts were characterized by ICP-OES, TEM and XPS. Their catalytic performance for the hydro-liquefaction of asphaltene to liquid fuels was investigated in a slurry bed reactor by using decalin as hydrogen donor and dispersant. The results show that the bimetal catalytic system composed of molybdenum dialkyl dithiophosphate and caproic acid nickel produces more MoS2 and NiS x active species. The metal contents of which accounts for 81.8 and 81.0 wt% of the total amount of Mo and Ni, respectively, and thus exhibits the best catalytic performance among the catalysts studied. The liquid yield of the asphaltene hydrogenation over the bimetal catalyst is 84.6 wt%, which is much higher than that over other catalysts, and the coke content is only 8.6 wt% under the conditions of 1000 μg/g of total metal addition, 1:1 Mo/Ni metal mass ratio and 1:1 asphaltene/naphthalene mass ratio. The content of saturated and aromatic components in the liquid products of asphaltene hydrogenation of the bimetal catalyst system is 78.9 wt%, which is a high-quality liquid fuel component.

scholarly journals An Escape from Noble Metals for Generating Urethanes via Reductive Carbonylation of Nitroarenes over FeSe2/γ-Al2O3 †

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1228
Author(s):  
Anh Vy Tran ◽  
Thuy Tram Huynh Nguyen ◽  
Thanh Tung Nguyen ◽  
Hye Jin Lee ◽  
Jayeon Baek ◽  
...  
Keyword(s):  
Noble Metals ◽  
Low Cost ◽  
Catalyst System ◽  
Catalytic Performance ◽  
Active Species ◽  
Significant Loss ◽  
Structure Characterization ◽  
Mechanistic Study ◽  
Characterization Methods ◽  
Reductive Carbonylation

The reaction of FeCl3, SeO2, and Pyridine (Py) in the presence of methanol (MeOH) under CO pressure generates a black precipitate, which has been confirmed as ferric di-selenide, FeSe2 through different structure characterization methods. Furthermore, impregnation of 5 wt% of FeSe2 onto γ-Al2O3 exhibits better catalytic performance than FeSe2 due to the highly dispersed and smaller particle sizes ca. 200–300 nm. The reductive carbonylation of nitrobenzene (NB) was investigated over FeSe2/γ-Al2O3 as a heterogeneous catalyst, delivering an excellent yield and high selectivity of methyl-N-phenyl carbamate (MPC). Moreover, a set of reactions was performed with variation in the reaction time, temperature, and pressure to investigate the effects of these factors. In particular, FeSe2/γ-Al2O3 is highly stable and can be recycled for up to five cycles without significant loss in catalytic performance. A mechanistic study was also conducted on this low-cost catalyst system, especially proposing a crucial role of FeSe2 (μ-CO) active species.

The Effects of Preparation Methods on Iron Structures of Iron-Supported HZSM-5 and their Catalytic Performance for Methanol Dehydration

2016 ◽  
Vol 723 ◽  
pp. 633-639
Author(s):  
Waenkaew Pantupho ◽  
Arthit Neramittagapong ◽  
Nuttawut Osakoo ◽  
Jatuporn Wittayakun ◽  
Sirinuch Loiha
Keyword(s):  
Flow Reactor ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Active Species ◽  
Iron Complex ◽  
Methanol Dehydration ◽  
Low Carbon ◽  
Zeolite Framework ◽  
Preparation Methods ◽  
Binuclear Iron

Iron-supported HZSM-5 catalysts were prepared by hydrothermal (Fe-HZSM-5_HYD) and impregnation methods (Fe/HZSM-5_IMP). The active species of binuclear-iron complex and iron-substituted zeolite framework, confirmed by EXAFS analysis, were observed on Fe/HZSM-5_IMP and Fe-HZSM-5_HYD, respectively. The catalysts were used for production of dimethyl ether (DME) by methanol dehydration at 200-350 °C using fixed bed flow reactor. Fe/HZSM-5_IMP showed higher catalytic conversion than Fe-HZSM-5_HYD. However, the Fe/HZSM-5_IMP catalyst was less selective to DME product and strongly deactivated for 24h. The deactivation might due to transformation of binuclear-iron to the a-iron site which was strong acidic strengh. The iron-substituted zeolite framework of Fe-HZSM-5_HYD showed high stability toward methanol dehydration. Moreover, the catalyst showed advantages of good selective to DME and low carbon deposition on surface. These results suggested that the iron-substituted zeolite framework structure could improve catalytic performance for mrthanol dehydration.

scholarly journals Preparation and Photocatalytic Performances of WO3/TiO2 Composite Nanofibers

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiuping Han ◽  
Binghua Yao ◽  
Keying Li ◽  
Wenjing Zhu ◽  
Xuyuan Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Composite Nanofibers ◽  
Photogenerated Electron ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Active Species ◽  
X Ray ◽  
Bet Analysis ◽  
Electron Holes

The use of sunlight for photocatalytic oxidation is an ideal strategy, but it is limited by factors such as insufficient light absorption intensity of the photocatalyst and easy recombination of photogenerated electron holes. TiO2 is favored by researchers as an environment-friendly catalyst. In this paper, TiO2 is combined with WO3 to obtain a nanofiber with excellent catalytic performance under sunlight. The WO3/TiO2 composite nanofibers were synthesized by using the electrospinning method. The X-ray diffraction (XRD) analysis indicated that WO3 was successfully integrated onto the surface of TiO2. The photodegradation performance and photocurrent analysis of the prepared nanofibers showed that the addition of WO3 really improved the photocatalytic performance of TiO2 nanofibers, methylene blue (MB) degradation rate increased from 72% to 96%, and 5% was the optimal composite mole percentage of W to Ti. The scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectra (UV-Vis DRS), and Brunauer-Emmett-Teller (BET) analysis further characterized the properties of 5% WO3/TiO2 nanofibers. The H2 generation rate of 5% WO3/TiO2 nanofibers was 107.15 μmol·g−1·h−1, in comparison with that of TiO2 nanofibers (73.21 μmol·g−1·h−1) under the same condition. The 5% WO3/TiO2 produced ·OH under illumination, which played an important role in the MB degradation. Also, the enhanced photocatalytic mechanism was also proposed based on the detailed analysis of the band gap and the active species trapping experiment. The results indicated that the effective separation of Z-scheme photogenerated electron-hole pairs and transfer system constructed between TiO2 and WO3 endowed the excellent photocatalytic activity of 5% WO3/TiO2 nanofibers.

scholarly journals Facile Synthesis of a Tailored-Designed Au/Pt Nanoanode for Enhanced Formic Acid, Methanol, and Ethylene Glycol Electrooxidation

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Islam M. Al-Akraa ◽  
Yaser M. Asal ◽  
Ahmad M. Mohammad
Keyword(s):  
Ethylene Glycol ◽  
Formic Acid ◽  
Energy Demand ◽  
Liquid Fuel ◽  
Surface Coverage ◽  
Co Adsorption ◽  
Catalytic Performance ◽  
Onset Potential ◽  
Anodic Reactions

The recent revolution in nanoscience and global energy demand have motivated research in liquid fuel cells (LFCs) due to their enhanced efficiency, moving flexibility, and reduced contamination. In line with this advancement, a glassy carbon (GC) electrode was modified with platinum (PtNPs) and gold (AuNPs) nanoparticles to fabricate a nanosized anode for formic acid, methanol, and ethylene glycol electrooxidation (abbreviated, respectively, to FAO, MO, and EGO), of the key anodic reactions of LFCs. The deposition sequence of the catalyst’s layers was important where the Au/Pt/GC electrode (in which PtNPs were directly deposited onto the GC surface followed by AuNPs—surface coverage ≈ 32%) exhibited the best catalytic performance. The catalytic performance of the Au/Pt/GC anode excelled (at least threefold) its value obtained at the Pt/GC anode with regard to FAO and EGO, if the oxidation peak currents were compared. This enhancement got reduced to 1.4 times in the case of MO, but the large decrease (− 220 mV) in the onset potential of MO provided compensation. The role of AuNPs in the Au/Pt/GC catalyst was principal in boosting its catalytic performance as it immunized the underlying PtNPs against CO poisoning which is associated with the release of CO as an intermediate during the oxidation. Interestingly, AuNPs succeeded in interrupting the contiguity of the Pt surface sites required for CO adsorption during FAO, MO, and EGO and, thus, presage preventing the deterioration of the catalytic performance of their corresponding LFCs.

scholarly journals Unexpected High Selectivity for Acetate Formation from CO2 Reduction with Copper Based 2D Hybrid Catalysts at Ultralow Potentials

2021 ◽  
Author(s):  
Rongming Cai ◽  
Mingzi Sun ◽  
Jiazheng Ren ◽  
Min Ju ◽  
Xia Long ◽  
...  
Keyword(s):  
High Selectivity ◽  
Co2 Reduction ◽  
Catalytic Performance ◽  
Active Species ◽  
Rapid Decay ◽  
Hybrid Catalysts ◽  
Commodity Chemicals ◽  
Acetate Formation

Copper-based catalysts are efficient for CO2 reduction affording commodity chemicals. However, the Cu(I) active species are easily reduced to Cu(0) during CO2RR, leading to rapid decay of catalytic performance. Herein,...

scholarly journals The position of liquid fuel residues in tank of worked-off rocket stage during ballistic descent

2021 ◽  
Vol 5 (1) ◽  
pp. 53-60
Author(s):  
V. Yu. Kudentsov ◽  
◽  
A. V. Kudentsov ◽  
Keyword(s):  
High Speed ◽  
Liquid Fuel ◽  
Side Surface ◽  
Fuel Tank ◽  
Rocket Fuel ◽  
Coverage Area ◽  
Fuel Component ◽  
Ballistic Trajectory ◽  
Liquid Rocket ◽  
Total Coverage

The results of modeling the behavior of liquid residues of the rocket fuel component in the fuel tank of the worked-off rocket stage on a ballistic trajectory are presented. The simulation is carried out for the following variants: during the controlled descent of the rocket stage and when using the technology of evaporation of liquid rocket fuel residues in the tanks of the spent stage. It is established that during the controlled descent of the spent rocket stage along the ballistic trajectory at the site of its turn and up to heights of 20 km, the liquid under the influence of overloads is distributed in the form of a film in the area of the bottom and side surface with a coverage area of up to 35 %. At the height of the maximum value of the axial overload, liquid fuel residues in the form of a film move to the area of the bottom and the adjacent side surface of the fuel tank. The total coverage area is about 22 %. The introduction of a hot coolant into the fuel tanks to vaporize the liquid remnants of rocket fuel radically changes the picture of the behavior of the liquid. Due to the high speed of the coolant in the tank, axial overload has little effect on the distribution of fuel residues in the rocket tank

Ammoxidation of 3-Picoline over V2O5/TiO2 Catalysts: Effects of TiO2 Supports on the Catalytic Performance

2011 ◽  
Vol 396-398 ◽  
pp. 791-797 ◽  
Author(s):  
Fu Min Zhang ◽  
Fei Chen ◽  
Qiang Xiao ◽  
Yi Jun Zhong ◽  
Wei Dong Zhu
Keyword(s):  
Catalytic Properties ◽  
External Surface ◽  
Weak Interactions ◽  
Catalytic Performance ◽  
Vanadium Oxides ◽  
Active Species ◽  
Direct Oxidation ◽  
N2 Adsorption ◽  
Wet Impregnation ◽  
Adsorption Desorption

A series of V2O5/TiO2catalysts were prepared by wet impregnation, and these prepared catalysts were characterized by XRD, N2 adsorption-desorption, H2-TPR, and TEM techniques and used in the selective ammoxidation of 3-picoline to 3-cyanopyridine. The effects of TiO2 supports on the catalytic properties of the resulting catalysts for the ammoxidation of 3-picoline to 3-cyanopyridine were investigated in detail. It is found that the V5+/V4+ transformation during ammoxidation is more favorable than the V5+/V3+ transformation for the selective ammoxidation of 3-picoline to 3-cyanopyridine. The V2O5/TiO2catalysts prepared from the nanosized TiO2particles as supports show a high activity for the direct oxidation of 3-picoline by air, resulting Subscript text Subscript textin a low selectivity for 3-cyanopyridine. This could be due to the fact that the active species vanadium oxides could be only supported on the external surface of the nano-sized TiO2particles with very minor contact area, leading to the weak interactions between active species and support.

scholarly journals Facile Fabrication of Z-Scheme Bi2WO6/WO3 Composites for Efficient Photodegradation of Bisphenol A with Peroxymonosulfate Activation

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 724 ◽  
Author(s):  
Yongkui Huang ◽  
Shuangwu Kou ◽  
Xiaoting Zhang ◽  
Lei Wang ◽  
Peili Lu ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Environmental Remediation ◽  
Radical Scavenging ◽  
Catalytic Performance ◽  
Active Species ◽  
Charge Migration ◽  
Facile Fabrication ◽  
Interface Contact ◽  
Photoinduced Charge

The rational fabrication of direct Z-scheme heterostructures photocatalysts is a pivotal strategy to boost the interfacial charge migration and separation. Herein, direct Z-scheme Bi2WO6/WO3 composites were rationally fabricated for the degradation of bisphenol A combined with the activation of peroxymonosulfate (PMS). The tight interface contact between Bi2WO6 and WO3 was successfully formed by the in situ epitaxial growth of ultrathin Bi2WO6 nanosheets at the surface of WO3 nanorods. The Bi2WO6/WO3 composite presented highly efficient catalytic performance toward degradation of BPA with PMS activation as compared to the WO3 and Bi2WO6. PMS can dramatically boost the photocatalytic activity of the composites. Moreover, the results of active radical scavenging experiments revealed that h+, •O2−, and •SO4− are critical active species in the photodegradation reaction. Finally, the photocatalytic mechanism for the degradation of BPA is also discussed in detail. The great improvement of photocatalytic performance should be ascribed to the effective formation of the direct Z-scheme heterojunctions between Bi2WO6 and WO3, resulting in improved light absorption, an efficient transfer and separation of photoinduced charge carriers, and a considerable amount of the electrons and holes with strong reduction and oxidation abilities. The study might provide new inspirations to design and construct heterostructured nanomaterials with outstanding photoactivity for environmental remediation.

Promotional Effect of Cr on Catalytic Performance of Fe/γ-Al2O3 for Ethylbenzene Dehydrogenation in the Presence of N2O

2011 ◽  
Vol 361-363 ◽  
pp. 932-935
Author(s):  
Shu Wei Chen ◽  
Xiao Fei Jia ◽  
Xing Yu Cui ◽  
Rui Feng Li
Keyword(s):  
Iron Oxide ◽  
Catalyst Deactivation ◽  
Catalytic Performance ◽  
Active Species ◽  
Ethylbenzene Dehydrogenation ◽  
Oxide Component ◽  
Promotional Effect ◽  
Catalytically Active ◽  
Soft Oxidant ◽  
Oxidative Dehydrogenation Of Ethylbenzene

This work shows that N2O, which causes global warming, could be effectively utilized as a soft oxidant in the oxidative dehydrogenation of ethylbenzene over alumina-supported iron oxide catalysts. The modification of the catalytically active iron oxide component with appropriate amounts of chromium oxide led to higher styrene yield (48.1%) with high styrene selectivity ( > 90%) at 500 °C and suppressed the catalyst deactivation for EB dehydrogenation under N2O. The improved catalytic behavior was attributed to the enhanced dispersion and redox properties of iron active species.

Sign in / Sign up

Export Citation Format

Share Document