Adsorptive removal of gaseous formaldehyde at realistic concentrations. Issue 4 (August 2020)

• Record Type: Journal Article
• Authors: Lara-Ibeas, Irene; Megías-Sayago, Cristina; Louis, Benoît; Le Calvé, Stéphane
• Is Part Of: Journal of environmental chemical engineering. Volume 8:Issue 4(2020)
• Publication Date: 2020-08
• Subjects: Formaldehyde -- Adsorption -- Zeolites -- Indoor air -- Gas analysis -- Realistic concentrations; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2020.103986
• Languages: English
• ISSNs: 2213-2929

Abstract

Highlights: Formaldehyde adsorption was studied over carbon, MOF, silica and zeolites at ppb levels. HKUST-1 showed the highest formaldehyde affinity. Formaldehyde adsorption is strongly related to Al content in ZSM-5 zeolites. Abstract: Due to analytical reasons, adsorption capacity is often determined at very high concentrations which is not representative of a real environment. The aim of this work is to provide experimental data of formaldehyde adsorption capacity at realistic levels (∼164 ppb) thanks to a near real-time powerful formaldehyde analyser recently developed in our laboratory. Gaseous formaldehyde breakthrough experiments were conducted on a broad spectrum of materials including carbon, zeolites, metal organic framework and mesoporous silica in order to determine their adsorption capacity. Among these materials, HKUST-1 exhibited the highest adsorption capacity (504 μg/g ads) followed by MgZSM-5 (35 μg /g ads), SBA-16 (29 μg/g ads), ZSM-5 (10–26 μg/g ads) and Carbopack® B (4 μg/g ads). In the case of ZSM-5 zeolites, the results revealed that formaldehyde adsorption was related to their aluminium content. The presence of aluminium implies more bridging hydroxyl groups Si-(OH)-Al that act as Brønsted acid sites interacting with formaldehyde molecules. Despite the moderate adsorption capacity of ZSM-5 zeolites, they can be considered as promising candidates for gas analysis applications, for example where a good analytical blank is essential for accurate measurements.