Enhancement of the non-thermal plasma-catalytic system with different zeolites for toluene removal

Abstract

Based on the important effect of catalyst on the plasma-catalytic system, various types of zeolites (5A, HZSM-5, Hβ, HY and Ag/HY) were chosen as catalysts to remove toluene under non-thermal plasma condition in this work. The results showed that all the zeolites, whether with toluene adsorption ability or not, significantly enhanced the toluene removal efficiency in the plasma discharge zone. Moreover, the carbon balance and CO 2 selectivity showed the same tendency of Ag/HY >HY > Hβ (HZSM-5)>5A, which was basically consistent with toluene adsorption ability, while opposed with the ozone emission. Loading silver on zeolite greatly decreased organic byproducts emission, and further improved the mineralization of toluene oxidation. At the same time, the intermediates including ringopening products on the catalyst surface were identified, and the pathways of toluene decomposition were proposed.

The Use of Zeolites for VOCs Abatement by Combining Non-Thermal Plasma, Adsorption, and/or Catalysis: A Review

“…The pore diameter of zeolite 5A is smaller than the dynamic toluene molecule diameter resulting in no adsorption. As shown in Figure 11, the breakthrough time for toluene adsorption on other zeolites (such as HZSM-5, Hβ and HY) follows the same order as that of the pore diameter [89]. The breakthrough time for toluene adsorption of HY zeolite is further increased by metal loading which will discussed in detail in the following section.…”

“…Ethylene adsorption of zeolite is enhanced two orders of magnitude (from 2.66 × 10 −4 to 3.37 × 10 −2 g per gram of catalyst) by the incorporation of Ag [46]. When compared to HY, Ag loaded HY can adsorb more toluene which is due to the π-complexation of Ag/HY with toluene [89].…”

“…Huang et al [89] investigated different zeolites such as MS-5A (5 Å), HZSM-5 (5.5 Å), Hβ (6.6 Å) and HY (7.4 Å) and reported that except MS-5A, other zeolites exhibited toluene adsorbing ability. The pore diameter of zeolite 5A is smaller than the dynamic toluene molecule diameter resulting in no adsorption.…”

“…× 10 −4 to 3.37 × 10 −2 g per gram of catalyst) by the incorporation of Ag [46]. When compared to HY, Ag loaded HY can adsorb more toluene which is due to the π-complexation of Ag/HY with toluene [89]. Several studies showed that metal loading on zeolite enhances the VOC adsorption capacity despite the reduction in their specific surface area [38,44,97].…”

Characteristics of toluene decomposition and adsorbent regeneration based on electrically conductive charcoal particle-triggered discharge

“…6,7 It was estimated that toluene covered 6.2% of the total industrial VOCs emission in China in 2013. 7 Toluene has been a common VOC used for investigation in previous studies on DBD, [8][9][10] gliding arc discharge, 11,12 corona discharge. 13,14 It was selected as a pollutant for testing in this study.…”