Monolithic stirrer reactors for the sustainable production of dihydroxybenzenes over 3D printed Fe/γ-Al2O3 monoliths: kinetic modeling and CFD simulation

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: C...

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Bibliographic Details
Authors: López, Pablo, Quintanilla Gómez, María Asunción, Salazar-Aguilar, Alma D., Vega-Díaz, Sofía M., Díaz-Herrezuelo, Irene, Belmonte, Manuel, Casas de Pedro, José Antonio
Format: article
Publication Date:2022
Country:España
Institution:Universidad Autónoma de Madrid
Repository:Biblos-e Archivo. Repositorio Institucional de la UAM
Language:English
OAI Identifier:oai:repositorio.uam.es:10486/705120
Online Access:http://hdl.handle.net/10486/705120
https://dx.doi.org/10.3390/catal12020112
Access Level:Open access
Keyword:CFD simulation
Dihydroxybenzenes
Kinetic model
Laminar flow stirred tank
Monolithic stirrer reactors
Phenol hydroxylation
Robocasting
Química
Description
Summary: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