Modeling initial decay of hydrodemetallization catalyst with simultaneous adsorption and reaction mechanism

Long, Fei; Gevert, Börje Sten

doi:10.1016/j.jcat.2003.10.026

Cited by 13 publications

(4 citation statements)

References 23 publications

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“…It is possible that the negative influence of the metal fouling is being negated by the deposited metals promoting enhanced catalytic activity. The metal deposits create new active sites as proposed by Long and Gevert . The deposited vanadium sulfide can display autocatalytic activity for HDM instead of being a poison …”

Section: Resultsmentioning

confidence: 96%

“…The metal deposits create new active sites as proposed by Long and Gevert. 35 The deposited vanadium sulfide can display autocatalytic activity for HDM instead of being a poison. 36 Vanadium, because of its high reaction rate, concentrates at the surface of the catalyst, whereas is distributed more evenly throughout the catalyst pellet.…”

Section: Energy and Fuelsmentioning

confidence: 99%

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Predicted Effects of Heavy Feeds on the Deactivation of a Commercial Atmospheric Residue Desulfurization Catalyst System

2018

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The effect of three atmospheric residual oils on the deactivation of a commercial atmospheric residue desulfurization (ARDS) catalyst system was assessed using a commercial catalyst system consisting of five catalysts loaded inside a two-reactor pilot plant. The hydrodemetalation (HDM) and hydrodesulfurization (HDS) reactions of the three residues over the catalyst system were studied. A deactivation model considering metals and carbon deposition was used to fit the life test data. Experimental and simulated data were compared. The effect of the residual oils on each of the catalysts was evaluated, and the catalyst contribution was calculated highlighting the importance of predicting different catalyst activities during the design of a composite catalyst bed.

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Section: Resultsmentioning

confidence: 96%

Section: Energy and Fuelsmentioning

confidence: 99%

Predicted Effects of Heavy Feeds on the Deactivation of a Commercial Atmospheric Residue Desulfurization Catalyst System

2018

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“…It is anticipated that biodiesel and crude glycerin production will continue to grow. Hydrogen is a clean energy source with uses including ammonia production, petroleum processing, and power generation in fuel cells. – Fossil fuels are currently used as the feed stock to satisfy 95% of U.S. hydrogen demand, and steam reforming of natural gas accounts for 48% . Reforming is a potential method for obtaining renewable hydrogen from crude glycerin.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Hydrogen Production from Glycerin Reforming

Douette¹,

Turn²,

Wang³

et al. 2007

Energy Fuels

102

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A series of tests were performed to investigate reforming of reagent-grade propane-1,2,3-triol, (C 3 H 8 O 3 ) commonly called glycerin, to produce a H 2 rich gas. Effects of the operating parameters, oxygen to carbon ratio, steam to carbon ratio, and temperature, were determined using a factorial experimental design. A mathematical model defining the effect of the three parameters was derived and used to improve the hydrogen yield. From the range of experimental conditions, it was concluded that the oxygen to carbon ratio, as well as the interaction between oxygen to carbon ratio and temperature had the most important effects on H 2 yield. A 4.5 mol quantity of hydrogen was produced per mole of glycerin at experimental conditions of oxygen to carbon ratio of 0, steam to carbon ratio of 2.2, and temperature of 804 °C. This is 65% of the maximum theoretical H 2 yield, and 90% of the H 2 yield predicted by thermochemical equilibrium. A 1.4 mol quantity of CO was also produced per mole of glycerin, presenting the potential for additional production of 1.4 mol H 2 /mol glycerin. A water gas shift reactor was added to the process and operated at 369 °C, producing a final yield of 5.3 mol H 2 /mol glycerin, 75% of the maximum stoichiometric hydrogen yield. Crude glycerin obtained from biodiesel production was finally tested (without the water gas shift reactor) as a feed and compared with reagent-grade glycerin results. The initial crude glycerin hydrogen yield, 4.4 mol H 2 /mol glycerin, was almost identical to that of reagent-grade glycerin, but carbon formation and coking increased the pressure drop through the catalyst bed causing the test to be terminated. Possible contaminants, chloride and sodium cations, present in crude glycerin as byproducts of biodiesel synthesis were added to reagent-grade glycerin and tested in the reformer, producing results similar to those observed for the crude glycerin reforming test.

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“…Studies on the modeling of fixed-bed reactors have been extensively reported (Froment et al, 1994;Chen and Ring, 2001;Gudekar and Riggs, 2003;Cerqueira et al, 1997;Long and Gevert, 2004;Berger et al, 2002). Froment et al (1994) reported a one-dimensional kinetic model and simulation in hydrodesulfurization of oil fractions using mixtures of model compounds as feed, which led to 93 unknown parameters for solving.…”

Section: Introductionmentioning

confidence: 99%

Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation

Botchwey¹,

Dalai²,

Adjaye³

2006

International Journal of Chemical Reactor Engineering

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A two-stage, micro trickle-bed reactor (for studies of the effects of hydrogen sulfide on hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of Athabasca bitumen-derived heavy gas oil over commercial NiMo/Al 2 O 3 catalyst) has been simulated. One dimensional homogeneous mass transfer and a two dimensional heat transfer models were developed. The essence of the simulation was to enhance the understanding of the effects of hydrogen sulfide in the hydrotreating catalyst bed in a two-stage mode and also to predict the catalyst requirements for deep HDS and HDN processes. The kinetic model used in the simulation was based on the Langmuir-Hingshelwood method of rate determination. Adsorption constants were estimated by non-linear least squares method. The kinetic models were tested on independent set of data and found to predict the experimental data satisfactorily. The mass transfer simulation considered the effects of variables such as temperature and catalyst loading or liquid hourly space velocity (LHSV) on the trends of hydrogen sulfide generation and, sulfur and nitrogen conversions along the catalyst bed. The model was numerically solved using a fourth-order Runge-Kutta technique. The 1:3 wt/wt catalyst loading with inter-stage hydrogen sulfide removal was found to give the best HDN and HDS activities. Simulated results showed that doubling the present catalyst mass and operating at 653 • C with inter-stage hydrogen sulfide removal would give 6 and 179 ppm product sulfur and nitrogen, respectively. On the other hand, without hydrogen sulfide removal, only 49 and 302 ppm product sulfur and nitrogen could be attained, respectively. The heat transfer simulation compared temperature profiles in the two-stage process to a single stage process for the 1:3 wt/wt catalyst Brought to you by | University of Connecticut Authenticated Download Date | 5/29/15 7:09 AM loading at 653 K. The temperature regime in Stage II was found to be more uniform unlike Stage I and the single stage. Crank Nicholson algorithm was used to solve the 2-D partial differential equations.

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Modeling initial decay of hydrodemetallization catalyst with simultaneous adsorption and reaction mechanism

Cited by 13 publications

References 23 publications

Predicted Effects of Heavy Feeds on the Deactivation of a Commercial Atmospheric Residue Desulfurization Catalyst System

Predicted Effects of Heavy Feeds on the Deactivation of a Commercial Atmospheric Residue Desulfurization Catalyst System

Experimental Investigation of Hydrogen Production from Glycerin Reforming

Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation

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