Chlorinated volatile organic compounds (VOCs), such as 1,1-dichloroethylene (DCE) and aromatic hydrocarbons, BTX (benzene, toluene, and xylene) constitute a significant fraction of the hazardous air and water pollution. Among this category of compounds, Methyl Tertiary Butyl Ether (MTBE) and toluene (TOL) are of special relevance since both are toxic and commonly found in natural water. Recently, high-silica zeolites were shown to be more effective in removing certain organics from water than activated carbon. Particularly, hydrophobic ZSM-5 (MFI-type framework topology) turned out that ZSM5 is the most promising zeolite support for VOC combustion,and many studies in literature deals with the adsorption properties of this zeolite from gas phase mixture. However, it has also been found that in gas phase water play an important role in regulating the interaction between organic compounds and zeolite. In this work, MTBE and TOL adsorption onto an organophilic zeolite ZSM5 was studied by using different combined techniques (diffractometric, thermogravimetric and gas chromatographic) to investigate the mechanisms of adsorption: 1) the adsorptive kinetics and thermodynamics properties of hydrophobic synthetic ZSM5; 2) characterise its structure after the adsorption of MTBE and TOL from aqueous solutions; 3) localise the organic species and water in the ZSM5 channel system.
Adsorption and Location of methylterbutylether and toluene nonto hydrofhobic ZSM-5 zeolite: a Diffractometric, Thermogravimetric and Gas Chromatographic study.
MARTUCCI, Annalisa;NASSI, Marianna;ALBERTI, Alberto;PASTI, Luisa
2011
Abstract
Chlorinated volatile organic compounds (VOCs), such as 1,1-dichloroethylene (DCE) and aromatic hydrocarbons, BTX (benzene, toluene, and xylene) constitute a significant fraction of the hazardous air and water pollution. Among this category of compounds, Methyl Tertiary Butyl Ether (MTBE) and toluene (TOL) are of special relevance since both are toxic and commonly found in natural water. Recently, high-silica zeolites were shown to be more effective in removing certain organics from water than activated carbon. Particularly, hydrophobic ZSM-5 (MFI-type framework topology) turned out that ZSM5 is the most promising zeolite support for VOC combustion,and many studies in literature deals with the adsorption properties of this zeolite from gas phase mixture. However, it has also been found that in gas phase water play an important role in regulating the interaction between organic compounds and zeolite. In this work, MTBE and TOL adsorption onto an organophilic zeolite ZSM5 was studied by using different combined techniques (diffractometric, thermogravimetric and gas chromatographic) to investigate the mechanisms of adsorption: 1) the adsorptive kinetics and thermodynamics properties of hydrophobic synthetic ZSM5; 2) characterise its structure after the adsorption of MTBE and TOL from aqueous solutions; 3) localise the organic species and water in the ZSM5 channel system.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
