Energy-efficient capture of volatile organic compounds from humid air by granular metal organic gel

Xianming Zheng; Huiyu Zhang; Sadia Rehman; Pengyi Zhang

doi:10.1016/j.jhazmat.2021.125057

Energy-efficient capture of volatile organic compounds from humid air by granular metal organic gel

J Hazard Mater. 2021 Jun 5:411:125057. doi: 10.1016/j.jhazmat.2021.125057. Epub 2021 Jan 9.

Authors

Xianming Zheng¹, Huiyu Zhang¹, Sadia Rehman¹, Pengyi Zhang²

Affiliations

¹ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
² State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory for Indoor Air Quality Evaluation and Control, Beijing 100084, China. Electronic address: zpy@tsinghua.edu.cn.

PMID: 33465540
DOI: 10.1016/j.jhazmat.2021.125057

Abstract

The discovery of granular adsorbents for the capture of volatile organic compounds (VOCs) from humid air and rapid regeneration at low temperature is still a challenge. Here we reported formation of a granular Al-based metal organic gel, CAU-3-NH₂(gel), by adjusting heating up time in the synthesis procedure. The water and thermal stable xerogel shows high surface area (1964 m²/g) and adsorption capacity for VOCs (uptakes of toluene and hexanal reach 4.5 and 3.85 mmol/g at P/P₀ = 0.1, respectively). Dynamic adsorption experiments further conformed its outstanding adsorption performance for toluene under 50% RH, higher than that of commercial adsorbents and widely studied MOFs including BPL activated carbon, ZSM-5, zeolite 13X, XAD-16, MIL-101(Cr), CAU-1 and ZIF-8. Under the mass space velocity of 12,000 mL/g.h, CAU-3-NH₂(gel) kept 99.95% removal ratio of low concentration toluene (100 ppm) over 12 h in 3 cycles at 298 K. Furthermore, desorption experiments show its excellent regenerability under mild temperature (328 K and 358 K). The interaction of toluene-framework and adsorption process are investigated by using Grand Canonical Monte Carlo (GCMC) simulations.

Keywords: Adsorption; Granular gel; Metal organic gel; Rapid regeneration; VOCs.