Photocatalytic oxidation of n-decane in a NETmix photoreactor: Insights into the reactor geometry and illumination mechanism

• Type: Article in International Scientific Journal
• Date: 2024

Authors

Miranda, M (Author) Other; Matiazzo, T (Author) Other; Padoin, N (Author) Other; Soares, C (Author) Other; Tânia Silva (Author) FEUP; Vitor Vilar (Author) FEUP

Journal

Title: Chemical Engineering Journal

Vol. 497

ISSN: 1385-8947

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Associated Projects

LA LSRE-LCM - Financiamento Plurianual 2020-2023 para a Unidade LA LSRE-LCM Laboratório de Processos de Separação e Reacção - Laboratório de Catálise e Materiais

Other information

Authenticus ID: P-016-VJ1

DOI: 10.1016/j.cej.2024.154705

Abstract (EN): This study focuses on the gas-phase photocatalytic degradation of n-decane using a NETmix photoreactor illuminated by UVA light-emitting diodes. The photoreactor is a static mixer composed of a network of cylindrical chambers interconnected by prismatic channels imprinted in a stainless-steel slab sealed with a borosilicate glass slab (reactor window with 55.7 cm(2) of illuminated area). Photocatalytic performance was evaluated as a function of the flow rate (0.67 to 15 L min(-1)), corresponding to Reynolds number (Re) from 54 to 1209, using NETmix plates with 1 mm (92.3 cm(2)) and 3 mm depth (165.4 cm(2)), under back-side (BSI) and front-side (FSI) illumination mechanisms. The TiO2-P25 loading over the borosilicate slab (25-100 mg; BSI optimal: 75 mg) and stainless-steel slabs (100-400 mg; FSI-1/FSI-3 optimal: 200/400 mg) was optimized. Within system constraints, higher Re corresponds to increased reaction rate, apparent quantum yield, and reactivity, with decreased degradation efficiency, due to a reduction in the residence time, regardless of the reactor geometry and illumination. Moreover, operating at the same Re, the NETmix plate with 3 mm depth achieves reaction rates 2.2-/1.9-fold higher than 1 mm, considering FSI/BSI mechanisms. The results were consistent with applied experimental conditions and ray tracing simulations, indicating superior kinetic performance with higher catalyst superficial area. Ray tracing was coupled with Computational Fluid Dynamics (CFD) simulations to evaluate n-decane single-pass oxidation. A 94 % n-decane maximum experimental conversion was attained for a Re of 54, representing an error of similar to 6.6 % compared to CFD simulation. In these conditions, only 1 % of n-decane was not mineralized, being identified aldehydes, alkanes, carboxylic acids, and ketones as the main reaction by-products. The influence of relative humidity (2 %-40 %) and n-decane inlet concentration (15-114 ppm) were also investigated.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13