Highly dispersed Fe3+-Al2O3 for the Fenton-like oxidation of phenol in a continuous up-flow fixed bed reactor: enhancing catalyst stability through operating conditions
| Autor: | Patricia Monica Haure, Carla di Luca, Sergio Gustavo Marchetti, Rosa Juana Fenoglio, Javier Mario Grau, Paola Andrea Massa |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
inorganic chemicals
Catalyst deactivation 02 engineering and technology INGENIERÍAS Y TECNOLOGÍAS 010402 general chemistry Phenol Removal 01 natural sciences Catalysis law.invention chemistry.chemical_compound Adsorption Physisorption Continuous fixed bed reactor law Phenol removal Fe3+-al2o3 Phenol Calcination Point of zero charge Hydrogen peroxide General Environmental Science Chemistry Process Chemistry and Technology Catalyst Deactivation Química 021001 nanoscience & nanotechnology Continuous Fixed Bed Reactor 0104 chemical sciences Ingeniería Química purl.org/becyt/ford/2.4 [https] purl.org/becyt/ford/2 [https] Fe3+-Al2o3 Otras Ingeniería Química Chelating Intermediates Chelating intermediates Leaching (metallurgy) 0210 nano-technology Nuclear chemistry |
| Zdroj: | SEDICI (UNLP) Universidad Nacional de La Plata instacron:UNLP CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| Popis: | A highly dispersed Fe3+-Al2O3 catalyst (6 wt% Fe) was used for the catalytic wet hydrogen peroxide oxidation of phenol (1 g/L) in an up-flow fixed bed reactor (UFBR) under continuous operation. To enhance catalytic performance, three simple synthesis strategies were combined: two-stage impregnation of iron citrate, acid washing with CH3COOH and thermal treatment at 900 °C. Solid samples were characterized in depth by several techniques: N2 Physisorption, XRD, SEM–EDAX, TEM, TGA, PZC, TPD of pyridine, XPS and Mössbauer. Peroxidation experiments were performed in an UFBR over a wide range of operating parameters in order to evaluate their influence on phenol mineralization and catalyst stability. Under selected operating condition (T = 90 °C, Wcat = 20 g, QL = 1.2 mL/min and [H2O2]:[Phenol] = 16.8), complete phenol conversion and remarkable TOC reduction of 90% were achieved, with a high H2O2 consumption efficiency (η = 76%) and low Fe leaching (< 3 mg/L). After 70 h of usage at different steady state conditions, the catalyst retained high mineralization levels (XTOC> 70%) but the cumulative iron loss was calculated to be c.a. 20% of the initial Fe loaded in the UFBR. The catalyst was susceptible to leaching due to the accumulation of complexing intermediates such as carboxylic acids. However, acceptable iron leaching values (< 10 mg/L) were achieved when the reactor operating conditions were properly set (55% < XTOC> 80%). The presence of chelating by-products favored also the Fe redistribution inside the catalyst pellets. Nevertheless, catalyst decay in the long-term operation was mainly due to the occurrence and permanence of chelating organic acids. This process was specially promoted by the amphoteric character of the alumina-based catalyst. However, adsorbed species were promptly eliminated by calcination at 500 °C, recovering steady state conversion profiles. Centro de Investigación y Desarrollo en Ciencias Aplicadas |
| Databáze: | OpenAIRE |
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