3D honeycomb monoliths with interconnected channels for the sustainable production of dihydroxybenzenes: towards the intensification of selective oxidation processes

Vega, Gonzalo; Quintanilla, A.; Menéndez, Nieves; Belmonte, Manuel; Casas, J.A.

doi:10.1016/j.cep.2021.108437

Cited by 15 publications

(44 citation statements)

References 38 publications

(2 reference statements)

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“…Along with them, resorcinol (RSL) and p-benzoquinone (BQ) are detected in very low concentrations (one order of magnitude lower, see Figure S3 of the Supporting Material). BQ is in redox equilibrium with the HQ [29], therefore both have been lumped as HQ for the further discussion and without introducing a significant error due to the far lower production of BQ comparing to HQ. As can be seen in Figure 1c,d, CTL is the majority product and the CTL:HQ molar ratio is around 1.6.…”

Section: Catalytic Performancementioning

confidence: 99%

“…However, in this latter case, S DHBZ = 100% and Y DHBZ = 32% were reported at 85 • C while these values diminish to S DHBZ = 75% and Y DHBZ = 22% in the MSR. This means that the phenol condensation and overoxidation of DHBZ, both reactions accounted as tar products [29], are more favorable in the MSR than MFBR. According to these results, to operate under the H 2 O 2 mass transfer control, as occurred in the MFBR, is beneficial to improve the S DHBZ in the catalytic hydroxylation of phenol.…”

Section: Kinetic Modelingmentioning

confidence: 99%

“…Likely, a slower H 2 O 2 decomposition rate allows a better use of the HO• radical species involved in the oxidation of phenol and avoid their availability for the further DHBZ oxidation. In addition, the low liquid volume in the reactor, as in MFBR, is beneficial to suppress the phenol condensation and overoxidation [29]. In contrast, the 3D Fe/Al 2 O 3 catalyst stability is higher under the MSR operation.…”

Section: Kinetic Modelingmentioning

confidence: 99%

“…In this line, this paper aims to provide insight into the implementation of MSR by the integration of the 3D printed technology for the monolithic catalyst manufacturing and computational fluid dynamic (CFD) simulation for a better understanding of the flow and species mass transport in the stirrer reactor. To achieve this goal, the hydroxylation of phenol by H 2 O 2 in aqueous phase over iron 3D catalysts has been studied as a sustainable industrial process [29]. This is a liquid-solid limited mass transfer reaction with respect to H 2 O 2 , as has been demonstrated in our previous work disposing the 3D Fe/Al 2 O 3 monoliths, manufactured by the Robocasting technique, in a fixed-bed configuration [30].…”

Section: Introductionmentioning

confidence: 99%

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Monolithic Stirrer Reactors for the Sustainable Production of Dihydroxybenzenes over 3D Printed Fe/γ-Al2O3 Monoliths: Kinetic Modeling and CFD Simulation

et al. 2022

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The aim of this work is to evaluate the performance of the stirring 3D Fe/Al2O3 monolithic reactor in batch operation applied to the liquid-phase hydroxylation of phenol by hydrogen peroxide (H2O2). An experimental and numerical investigation was carried out at the following operating conditions: CPHENOL,0 = 0.33 M, CH2O2,0 = 0.33 M, T = 75–95 °C, P = 1 atm, ω = 200–500 rpm and WCAT ~ 1.1 g. The kinetic model described the consumption of the H2O2 by a zero-order power-law equation, while the phenol hydroxylation and catechol and hydroquinone production by Eley–Rideal model; the rate determining step was the reaction between the adsorbed H2O2, phenol in solution with two active sites involved. The 3D CFD model, coupling the conservation of mass, momentum and species together with the reaction kinetic equations, was experimentally validated. It demonstrated a laminar flow characterized by the presence of an annular zone located inside and surrounding the monoliths (u = 40–80 mm s−1) and a central vortex with very low velocities (u = 3.5–8 mm s−1). The simulation study showed the increasing phenol selectivity to dihydroxybenzenes by the reaction temperature, while the initial H2O2 concentration mainly affects the phenol conversion.

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Section: Catalytic Performancementioning

confidence: 99%

Section: Kinetic Modelingmentioning

confidence: 99%

Section: Kinetic Modelingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Monolithic Stirrer Reactors for the Sustainable Production of Dihydroxybenzenes over 3D Printed Fe/γ-Al2O3 Monoliths: Kinetic Modeling and CFD Simulation

et al. 2022

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“…In particular, a rising number of publications explore the rational design and preparation of 3D monolithic catalytic systems with nonconventional geometries. − The most common ones are the honeycomb monoliths with interconnected straight channels ,,,,, and also cross-channel structures. , More complex ones are honeycomb monoliths with asymmetrical channels either by a progressive decrease in the channel section along the monolith or by alternating wide and narrow channels . In addition, parallel channels with new cell morphologies, i.e .…”

Section: Introductionmentioning

confidence: 99%

Enhanced Fluid Dynamics in 3D Monolithic Reactors to Improve the Chemical Performance: Experimental and Numerical Investigation

Quintanilla

Vega

López

et al. 2021

Ind. Eng. Chem. Res.

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Three-dimensional (3D) Fe/SiC monoliths with parallel interconnected channels and different cell geometries (square, troncoconical, and triangular) were manufactured by robocasting and used as catalytic reactors in hydroxylation of phenol using hydrogen peroxide to produce dihydroxybenzenes; the reaction was performed at C phenol,0 = 0.33 M, C phenol,0 :C H 2 O 2 ,0 = 1:1 M, W R = 3.7 g, T = 80−90 °C, and τ = 0−254 g cat •h•L −1 with water as a solvent. The values of the apparent kinetic rate constants demonstrated the superior performance of the triangular cell monoliths for hydrogen peroxide decomposition , phenol hydroxylation, and dihydroxybenzene production reactions. A computational fluid dynamic model was validated with the experimental results. It demonstrated that the triangular cell monoliths, with a lower channel hydraulic diameter and not-facing interconnections, provided a higher internal macrotortuosity that induced an oscillating flow of the liquid phase inside the channels, leading to an additional transverse flow between adjacent parallel channels. This behavior, not observed in the other two geometries, resulted in a better overall performance.

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Modeling and experimental analysis of CO2 methanation reaction using Ni/CeO2 monolithic catalyst

Parra-Marfil,

Ocampo-Pérez,

Aguilar-Madera

et al. 2024

Environ Sci Pollut Res

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In this study, the effect of the cell density of monolithic catalysts was investigated and further mathematically modeled on cordierite supports used in CO2 methanation. Commercial cordierite monoliths with 200, 400, and 500 cpsi cell densities were coated by immersion into an ethanolic suspension of Ni/CeO2 active phase. SEM–EDS analysis confirmed that, owing to the low porosity of cordierite (surface area < 1 m2 g−1), the Ni/CeO2 diffusion into the walls was limited, especially in the case of low and intermediate cell density monoliths; thus, active phase was predominantly loaded onto the channels’ external surface. Nevertheless, despite the larger exposed surface area in the monolith with high cell density, which would allow for better distribution and accessibility of Ni/CeO2, its higher macro-pore volume resulted in some introduction of the active phase into the walls. As a result, the catalytic evaluation showed that it was more influenced by increments in volumetric flow rates. The low cell density monolith displayed diffusional control at flow rates below 500 mL min−1. In contrast, intermediate and high cell density monoliths presented this behavior up to 300 mL min−1. These findings suggest that the interaction reactants-catalyst is considerably more affected by a forced non-uniform flow when increasing the injection rate. This condition reduced the transport of reactants and products within the catalyst channels and, in turn, increased the minimum temperature required for the reaction. Moreover, a slight diminution of selectivity to CH4 was observed and ascribed to the possible formation of hot spots that activate the reverse water–gas shift reaction. Finally, a mathematical model based on fundamental momentum and mass transfer equations coupled with the kinetics of CO2 methanation was successfully derived and solved to analyze the fluid dynamics of the monolithic support. The results showed a radial profile with maximum fluid velocity located at the center of the channel. A reactive zone close to the inlet was obtained, and maximum methane production (4.5 mol m−3) throughout the monolith was attained at 350 °C. Then, linear streamlines of the chemical species were developed along the channel.

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3D honeycomb monoliths with interconnected channels for the sustainable production of dihydroxybenzenes: towards the intensification of selective oxidation processes

Cited by 15 publications

References 38 publications

Monolithic Stirrer Reactors for the Sustainable Production of Dihydroxybenzenes over 3D Printed Fe/γ-Al2O3 Monoliths: Kinetic Modeling and CFD Simulation

Monolithic Stirrer Reactors for the Sustainable Production of Dihydroxybenzenes over 3D Printed Fe/γ-Al2O3 Monoliths: Kinetic Modeling and CFD Simulation

Enhanced Fluid Dynamics in 3D Monolithic Reactors to Improve the Chemical Performance: Experimental and Numerical Investigation

Modeling and experimental analysis of CO2 methanation reaction using Ni/CeO2 monolithic catalyst

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