Characterization of direct coal liquefaction catalysts by their sulfidation behavior and tetralin dehydrogenation activity

Chen, Zezhou; Xie, Jing; Liu, Qingya; Wang, Hongxue; Gao, Shansong; Shi, Lei; Liu, Zhenyu

doi:10.1016/j.joei.2018.05.009

Cited by 20 publications

(11 citation statements)

References 29 publications

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“…Additionally, the reactor internal diameter (20 mm) is significantly larger than the size of the catalyst particles. An activation energy in a similar range was reported by Chen [20] for Mo supported on coal char as catalyst for tetralin dehydrogenation, though the rate constant was almost same, the activation energy obtained with NiMo/Al 2 O 3 used in this study was slightly lower.…”

Section: Fixed-bed Reaction Kineticssupporting

confidence: 84%

“…Thermodynamically, high temperature is necessary to provide sufficient thermal energy for this endothermic reaction; hence, the conversion of tetralin via dehydrogenation to naphthalene and hydrogen liberation increased as temperature increased from 250 to 350 °C. Chen et al [20] observed a similar trend in tetralin conversion against time-on-stream and as reaction temperature increase. As expected, the endothermic nature of tetralin dehydrogenation process is favoured with increasing temperature.…”

Section: Conversion Selectivity and Liberated Hydrogenmentioning

confidence: 63%

“…The first is that dehydrogenation is an endothermic reaction that requires high temperature, and the temperature of the hot oil passing over the catalyst bed in the THAI-CAPRI is in the range of only 100 to 300 °C [6], which is non-uniform and also below 425 °C needed for effective catalytic upgrading. The other is that the produced naphthalene will compete with the heavy oil molecules for adsorption on the catalyst active sites [19,20]. Since the catalyst bed under IH functions as a heat generator, the first challenge can be addressed unlike conventional heating (CH) system where the catalyst bed acts as a heat sink.…”

Section: Introductionmentioning

confidence: 99%

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Inductive Heating Assisted-Catalytic Dehydrogenation of Tetralin as a Hydrogen Source for Downhole Catalytic Upgrading of Heavy Oil

et al. 2019

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The Toe-to-Heel Air Injection (THAI) combined with a catalytic add-on (CAPRI, CATalytic upgrading PRocess In-situ) have been a subject of investigation since 2002. The major challenges have been catalyst deactivation due to coke deposition and low temperatures (~ 300 °C) of the mobilised hot oil flowing over the catalyst packing around the horizontal well. Tetralin has been used to suppress coke formation and also improve upgraded oil quality due to its hydrogen-donor capability. Herein, inductive heating (IH) incorporated to the horizontal production well is investigated as one means to resolve the temperature shortfall. The effect of reaction temperature on tetralin dehydrogenation and hydrogen evolution over NiMo/ Al 2 O 3 catalyst at 250-350 °C, catalyst-to-steel ball ratio (70% v/v), 18 bar and 0.75 h −1 was investigated. As temperature increased from 250 to 350 °C, tetralin conversion increased from 40 to 88% while liberated hydrogen increased from 0.36 to 0.88 mol based on 0.61 mol of tetralin used. The evolved hydrogen in situ hydrogenated unreacted tetralin to trans and cis-decalins with the selectivity of cis-decalin slightly more at 250 °C while at 300-350 °C trans-decalin showed superior selectivity. With IH the catalyst bed temperature was closer to the desired temperature (300 °C) with a mean of 299.2 °C while conventional heating is 294.3 °C. This thermal advantage and the nonthermal effect from electromagnetic field under IH improved catalytic activity and reaction rate, though coke formation increased.

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Section: Fixed-bed Reaction Kineticssupporting

confidence: 84%

Section: Conversion Selectivity and Liberated Hydrogenmentioning

confidence: 63%

Section: Introductionmentioning

confidence: 99%

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Inductive Heating Assisted-Catalytic Dehydrogenation of Tetralin as a Hydrogen Source for Downhole Catalytic Upgrading of Heavy Oil

et al. 2019

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“…Thermodynamically, the liberation of hydrogen from polycyclic organic compounds such as tetralin and decalin is favored at high temperatures, such as 425 • C [17,31]. In the case of tetralin, the complete dehydrogenation of a mole produces naphthalene and only two moles of hydrogen; hence, the reaction medium could have experienced limited hydrogen supply to adequately quench radical fragments of macromolecular weight hydrocarbons [32,33]. This could be the possible reason for the marginally lower coke formation (4.4% decrease in formed coke) with the addition of tetralin solvent, compared with nitrogen gas environment alone.…”

Section: Hydrogen Donor Routesmentioning

confidence: 99%

Tetralin and Decalin H-Donor Effect on Catalytic Upgrading of Heavy Oil Inductively Heated with Steel Balls

et al. 2020

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The Toe-to-Heel Air Injection (THAI) combined with catalytic upgrading process in situ (CAPRI) has demonstrated it can simultaneously extract and upgrade heavy oil in situ. This paper reports the investigation of augmenting temperature deficit and suppressing coke formation in the CAPRI section through the incorporation of induction heating and H-donor solvents. An induction-heated catalytic reactor was designed and developed, heated with steel balls in a mixed bed of NiMo/Al2O3 catalyst (66% v/v) to 425 °C temperature, 15 bar pressure and 0.75 h−1 LHSV (Liquid Hourly Space Velocity). The catalyst surface area, pore volume and pore size distribution were determined by using nitrogen adsorption–desorption, while the location of coke deposits within the microstructure of the pelleted spent catalyst was analyzed with X-ray nano-Computed Tomography (X-ray nano-CT). Findings showed that induction heating improved the catalyst performance, resulting in a 2.2° American Petroleum Institute (API) gravity increase of the upgraded oil over that achieved with the conventional heating method. The increment in API gravity and viscosity reduction in the upgraded oils with nitrogen gas only, N2 and H-donor solvents, and hydrogen gas environments can be summarized as follows: decalin > H2 gas >= tetralin > N2 gas. Meanwhile, the improvement in naphtha fraction, middle distillate fractions and suppression of coke formation are as follows: decalin > H2 gas > tetralin > N2 gas. The X-ray nano-CT of the spent catalyst revealed that the pellet suffers deactivation due to coke deposit at the external surface and pore-mouth blockage, signifying underutilization of the catalyst interior surface area.

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“…On the other hand, carbon deposition and metallic impurities can easily cause the deactivation of catalyst under operating conditions. It is widely accepted that catalyst is the key to improving the utilization rate of coal and inferior oil, which has attracted major attention of many scientists (Ikenaga et al 1997;Bodman et al 2002;Chianelli et al 2009;Nikulshin et al 2014;Li et al 2018;Chen et al 2019). As more and more people are keen on developing innovative hydrogenation catalysts, the pace of progress in this area is accelerating.…”

Section: Introductionmentioning

confidence: 99%

Study on Hydrogenation Performance of Oil-Soluble Molybdenum Catalyst in Coal-Oil Co-Processing

Wang

Xiqian

Zhao

2022

Preprint

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An oil-soluble molybdenum catalyst was synthesized by a simple and novel method and studied for hydrogenation in coal-oil co-processing. The catalyst was characterized by infrared spectrum (IR), thermogravimetry (TG), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The morphology and crystal structure of catalyst was characterized with scanning electron microscope (SEM) and high resolution transmission electron microscopy (HRTEM). The catalyst can be considered as a precursor that can be converted into active MoS2 components through thermal decomposition and sulfidation. The hydrogenation experiment was carried out by the model reactants of tetradecane and 2-methylnaphthalene with a change of reaction (405℃-445℃) temperature and concentrations of molybdenum catalyst (Mo conc. 0.6-10 mg/g), and results showed that the delightly hydrogenation function of catalyst is to improve the saturation of aromatic ring. The most abundant stacking numbers of decomposed catalyst were 2 and 3, accounting for 53% of all catalyst microcrystalline units. The rapid hydrogenation stage and the significant decrease of feed heavy fraction in co-processing experiment provided the evidence that the hydrogenation performance of the synthesized catalyst is remarkable in coal-oil co-processing.

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Characterization of direct coal liquefaction catalysts by their sulfidation behavior and tetralin dehydrogenation activity

Cited by 20 publications

References 29 publications

Inductive Heating Assisted-Catalytic Dehydrogenation of Tetralin as a Hydrogen Source for Downhole Catalytic Upgrading of Heavy Oil

Inductive Heating Assisted-Catalytic Dehydrogenation of Tetralin as a Hydrogen Source for Downhole Catalytic Upgrading of Heavy Oil

Tetralin and Decalin H-Donor Effect on Catalytic Upgrading of Heavy Oil Inductively Heated with Steel Balls

Study on Hydrogenation Performance of Oil-Soluble Molybdenum Catalyst in Coal-Oil Co-Processing

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