The removal of toluene vapors using metal-organic framework adsorbent

 Toluene (methylbenzene) is a volatile organic compound (VOC) that, when chronically exposed to low concentration, can cause a variety of adverse health effects, including immunological and neurological disorders. In addition, the release of toluene in the atmosphere causes various environmental problems, including the reduction of stratospheric ozone, the production of photochemical smog, and the increase of the greenhouse effect. The purpose of this research was to remove toluene from the air flow using imidazolate zeolite framework (ZIF-8) in order to be used in air purification processes and to prevent and reduce the risk of exposure to this hazardous pollutant in occupational settings and environments.

 Zeolite imidazolate framework (ZIF-8) was synthesized in situ, and its structure was investigated using X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and BET testing. The absorption performance of toluene by ZIF-8 in the gas phase was studied using a dynamic adsorption system developed according to BS EN ISO 10121-1:2014 and previous studies.

 The results of the structural tests showed that the synthesis of ZIF-8 was successful. Its specific area has also increased compared to several similar articles. The average toluene adsorption capacity of ZIF-8 at a temperature of 30.5 degrees Celsius, a relative humidity of 33%, and a flow rate of 300 ml/min, with a mass of 10 mg, was equal to 2828.91 mg/g. In addition, the initial removal efficiency is reported to be 88.67%. The breakthrough time for 100% of ZIF-8 was determined to be 21,660 seconds. The recovery rate after 6 cycles of ZIF-8 remained as high as 84.7%.

 ZIF-8 exhibits a high adsorption capacity for toluene in the gas phase, along with a high initial removal efficiency and breakdown time. Due to its effective ability to adsorb toluene, this MOF can be considered for use in air purification and purification processes. However, further studies are needed to fully evaluate its potential as an industrial adsorbent, taking into account relevant considerations.