Studies on Heat and Mass Transfer Limitations in Oxidative Dehydrogenation of Ethane Over Cr2O3 /Al2O3 Catalyst

Bai, Peng; Manokaran, V.; Saiprasad, P. S.; Suranani, Srinath

doi:10.1016/j.proeng.2015.11.492

Cited by 25 publications

(10 citation statements)

References 14 publications

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“…The Weisz-Prater criteria were used to confirm that the reaction is not diffusion-limited. [45][46][47][48] The details of calculations are provided in the supporting information. The supported catalysts were used directly for catalytic properties evaluation, without any activation/reduction in hydrogen as the synthesis conditions were maintained to get metallic/bimetallic form of copper and nickel.…”

Section: Experimental Techniquesmentioning

confidence: 99%

Effect of nickel on combustion synthesized copper/ fumed‐SiO ₂ catalyst for selective reduction of CO ₂ to CO

Kumar

Mohammed

Saad

et al. 2021

Intl J of Energy Research

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In this study, we explore the effect of nickel incorporation in Cu/fumed-SiO 2 catalyst for CO 2 reduction reaction. Two catalysts, Cu and CuNi supported on fumed silica were synthesized using a novel surface restricted combustion synthesis technique, where the combustion reaction takes place on the surface of the inert fumed-SiO 2 support. An active solution consisting of a known amount of metal nitrate precursors and urea (fuel) was impregnated on fumed silica. The catalyst loading was limited to 1 wt% to ensure localized combustions on the surface of fumed-SiO 2 by restricting the combustion energy density. The synthesized catalysts were tested for CO 2 hydrogenation reaction using a tubular packed bed reactor between temperature 50 C and 650 C, where Cu/SiO 2 showed high CO 2 conversion to carbon monoxide, and the addition of Ni further improved the catalytic performance and showed some tendency for methane formation along with CO. Moreover, both the catalysts were highly stable under the reaction conditions and did not show any sign of deactivation for $42 hours time on stream (TOS). The catalysts were characterized using X-ray diffractometer (XRD), scanning electron microscope/energy dispersive X-ray spectrometer (SEM/EDX), transmission electron microscope (TEM), and the Brunauer-Emmet-Teller (BET) surface area measurement technique to understand their structural properties and to assess the effect of CO 2 conversion reaction. In situ DRIFTS was also used to investigate the reaction pathway followed on the surface of the catalysts.

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Section: Experimental Techniquesmentioning

confidence: 99%

Effect of nickel on combustion synthesized copper/ fumed‐SiO ₂ catalyst for selective reduction of CO ₂ to CO

Kumar

Mohammed

Saad

et al. 2021

Intl J of Energy Research

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“…Mass transfer resistance of the heterogeneous catalytic reaction was checked by using the Weisz‐Prater criterion (for external diffusion from the bulk fluid to the external surface of the catalyst) and Mears criterion (for internal diffusion from the external surface into and through its pores). The mentioned internal and external mass transfer mechanisms could act as resistance which affects the rate of reaction 36 …”

Section: Diffusion Effects On Heterogeneous Reactionsmentioning

confidence: 99%

“…The Weisz‐Prater parameter ( C wp ) and Mears parameter ( C M ) were calculated by using Equations (4) and (5) 36 :

C_{normalWP} = \frac{r_{normalobs} ρ_{c} R_{P}^{2}}{D_{normaleff} C_{S}},

C_{M} = \frac{r_{normalobs} ρ_{b} R_{p} n}{k_{c} C_{normalAb}},

…”

Section: Diffusion Effects On Heterogeneous Reactionsmentioning

confidence: 99%

Biodiesel production in the presence of heterogeneous catalyst of alumina: Study of kinetics and thermodynamics

Zanjani

Pirzaman

Yazdanian

2020

Int J of Chemical Kinetics

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In the current research, biodiesel production was investigated in the presence of solid catalysts of K 2 CO 3 /Al 2 O 3 by transesterification of rapeseed oil. The specifications of produced fatty acid methyl esters like viscosity and flash point were studied, and it was noted that they complied with the requirements of ASTM D6751. In addition, the kinetic and thermodynamic parameters were explored considering the temperature changes between 318.15 and 348.15 K. Mass transfer resistance (external diffusion or internal diffusion) over the catalyst was neglected with regard to theWeisz-Prater criterion and Mears criterion. The kinetic models containing Eley-Rideal, Langmuir-Hinshelwood, pseudo-first-order, pseudo-second-order, and -order models were investigated. Corrected Akaike information criterion was utilized to find the best model fitted with the experimental data. The greatest illustration for the K 2 CO 3 /Al 2 O 3 -catalyzed reaction was the nonlinear model with an order of = 1.287 and the activation energy of 12.12 kJ/mol. Using transition state theory (Eyring-Polanyi equation), the activation Gibbs free energy, activation enthalpy, and activation entropy were calculated at different temperatures. The equilibrium thermodynamic properties depicted that this process is endothermic and spontaneous toward biodiesel production and tends to be irreversible. K E Y W O R D Salumina, heterogeneous catalyst, kinetics, thermodynamic, transesterification 472

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“…The macroscopic structure of solid catalysts can affect the efficiency of heat and mass transfer in chemical conversions. [1][2][3][4][5] Solid catalysts are typically manufactured by pelleting or extruding composites of pre-catalysts, promoters and binders. [6][7][8][9][10] Although these methods can yield different catalyst shapes like grids, beads, rods or foams, these topologies are not necessarily optimal for all types of reactor and process.…”

Section: Introductionmentioning

confidence: 99%

Macroscale Control of Reactivity using 3D Printed Materials with Intrinsic Catalytic Properties

Manzano

Wang

et al. 2020

Applied Catalysis A: General

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The morphology of heterogeneous catalysts can impact their performance by controlling the efficiency of heat and mass transfer. However, standard manufacturing methods such as extrusion or pelleting offer little options for optimizing catalyst shape. Herein, stereolithographic (SLA) 3D printing is used to directly produce catalysts with controlled morphologies to enhance their performance. A series of chemically active magnetic stir-bar compartments (SBC) were 3D printed and used as catalysts for sucrose hydrolysis. The SBCs were composed of acrylic acid (AA) and 1,6-hexanediol diacrylate (HDDA) which provided acid sites and hydrophobic crosslinking domains, respectively. Fixing the surface area and the number of accessible catalytic sites of the 3D printed SBC allowed exploring the effect of changes in morphology on the fluid dynamics of the reaction systems, and consequently on the efficiency of the catalytic hydrolysis. Moreover, varying the AA:HDDA ratios in SBC allowed tuning the surface-substrate interaction to control their catalytic activity for the hydrolysis of sucrose. This work demonstrates that 3D printing catalytic materials enable optimizing catalyst performance by simultaneously controlling macroscopic and molecular properties.

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Studies on Heat and Mass Transfer Limitations in Oxidative Dehydrogenation of Ethane Over Cr2O3 /Al2O3 Catalyst

Cited by 25 publications

References 14 publications

Effect of nickel on combustion synthesized copper/ fumed‐SiO ₂ catalyst for selective reduction of CO ₂ to CO

Effect of nickel on combustion synthesized copper/ fumed‐SiO ₂ catalyst for selective reduction of CO ₂ to CO

Biodiesel production in the presence of heterogeneous catalyst of alumina: Study of kinetics and thermodynamics

Macroscale Control of Reactivity using 3D Printed Materials with Intrinsic Catalytic Properties

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Studies on Heat and Mass Transfer Limitations in Oxidative Dehydrogenation of Ethane Over Cr2O3 /Al2O3 Catalyst

Cited by 25 publications

References 14 publications

Effect of nickel on combustion synthesized copper/ fumed‐SiO 2 catalyst for selective reduction of CO 2 to CO

Effect of nickel on combustion synthesized copper/ fumed‐SiO 2 catalyst for selective reduction of CO 2 to CO

Biodiesel production in the presence of heterogeneous catalyst of alumina: Study of kinetics and thermodynamics

Macroscale Control of Reactivity using 3D Printed Materials with Intrinsic Catalytic Properties

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Product

Resources

About

Effect of nickel on combustion synthesized copper/ fumed‐SiO ₂ catalyst for selective reduction of CO ₂ to CO

Effect of nickel on combustion synthesized copper/ fumed‐SiO ₂ catalyst for selective reduction of CO ₂ to CO