Adsorption of Xylene From Air by Natural Iranian Zeolite

Abstract

Background: Aromatic organic solvents are extensively used in various industries. Xylene is a colorless, transparent liquid, with the characteristic odor of the aromatic hydrocarbons family, which is widely used in industries. Adsorption is a conventional method of purifying polluted air containing volatile organic compounds (VOCs). Zeolite has many unique properties such as high capacity, molecular sieve characteristics, nonflammability, thermal stability, and strong acid sites. Moreover, it is reconstructed at low temperatures. Objectives: In this study, we investigated the effect of various parameters on the adsorption capacity of natural zeolite (clinoptilolite) for xylene adsorption. Materials and Methods: Physical and chemical properties of natural zeolites were tested by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) and elemental analyses of natural zeolites were characterized by X-ray diffraction. Xylene concentration was measured at various times through concentrations-measured valve before and after the adsorbent bed reactor by the direct reading of Phocheck (Ion Science Ltd, UK). Results: Experimental results showed that clinoptilolite is a potential sorbent for xylene in the range of ppm, and the breakthrough time would be reduced by increasing the concentration. The optimal temperature of xylene adsorption on natural zeolite was 35℃ and by increasing the temperature, the absorption efficiency of clinoptilolite was declined. The results showed that the breakthrough time and the exhaustion point time at the optimal conditions are 65 and 95 minutes, respectively. Adsorption capacity of clinoptilolite was obtained as 1.69 mg xylene/g zeolite. Conclusions: Experimental results showed that clinoptilolite is a potential sorbent for xylene in the range of ppm and the breakthrough time was reduced by increasing the concentration. Adsorption rate were increased by increasing concentration of xylene. Presence of xylene molecules in high concentration enhances their transfer and contact with adsorbent; as a result, by increasing gas concentration, breakthrough time in zeolite will be shorter.

Adsorption of Sulfur Dioxide on Clinoptilolite/Nano Iron Oxide and Natural Clinoptilolite

“…They reported that the adsorption decreases with increasing temperature and ∆H°is a negative value, which complies with the result of this study (39). Vhdat Parast et al found that by increasing the temperature, xylene adsorption on clinoptilolite is declined (40).…”

A rapid removal of xylene from air based on nano-activated carbon in the dynamic and static systems and compared to commercial activated carbon before determination by gas chromatography

“…Asilian also reported that increasing the amount of adsorbent cause to increase the adsorption efficiency. In fact, in this study, adsorption efficiency in low flowrate is was excellent and consistent [24]. Lu et al showed that the carbon nanotube oxidized with sodium hypochlorite had a higher BTEX adsorption than carbon nanotube and granular activated carbon.…”

“…The results of flow rate and amount of adsorbent in the present study were similar to the results of Asilian et al Asilian et al showed that the absorption capacity of xylene for zeolite was decreased up to 1.69 mg g -1 by increasing flow rate. Also, in a high flow rate, the time of failure and saturation time decreased in zeolite adsorbent [24]. Asilian also reported that increasing the amount of adsorbent cause to increase the adsorption efficiency.…”

Dynamic and static removal of benzene from air based on task-specific ionic liquid coated on MWCNTs by sorbent tube-headspace solid-phase extraction procedure

“…The different features for VOCs' removal such as recovery (%), absorption capacity (AC), and aromatic compounds are compared together. Based on the results, the ST/HS-SPE procedure was comparable to other sorbent which was reported in different works (Bagheri Hosseinabadi et al 2019;Osanloo and Qurban-Dadras 2014;Faghihi Zarandi et al 2018;Jahangiri et al 2011;Hansmeier, 2010;Bina et al 2012;Shariq Vohra 2015;Qi et al 2018;Gholami et al 2014;Liu et al 2016;Rostami and Jonidi Jafari 2014;Vahdat Parast et al 2014;Britt et al Table 1 Validation…”