Influence of acid and heavy metal cation exchange treatments on methane adsorption properties of mordenite

Abstract

Abstract:In this study, the adsorption of methane (CH 4) capacities onto natural mordenite obtained fromİzmir, Turkey, and its cationic forms (CuM, AgM, FeM, and HM samples) were investigated at the temperatures of 0 and 25• C up to 100 kPa. Natural and modified samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF),Fourier transform infrared (FT-IR), thermogravimetry (TG-DTG), differential thermal analysis (DTA), scanning electron microscopy (SEM) coupled with energy dispersion spectroscopy (EDS), and N 2 adsorption methods. Quantitative XRD analysis showed that the major component of the natural zeolite was mordenite, together with minor amounts of quartz, feldspar, and clay mineral. The specific surface area and microporosity of the mordenite sample decreased notably after Ag cation exchange treatment. It was found that the adsorption capacity and the affinity of CH 4 with mordenite samples depended mainly on the type of exchanged cations and increased as HM < FeM < CuM < M < AgM for 25• C. The uptake of methane increased as HM < FeM < CuM < AgM < M for 0 • C. Capacity of mordenites for CH 4 ranged from 0.237 mmol g −1 to 0.528 mmol g −1 .

Nylon-6–Mordenite Composite Membranes for Adsorption of Ethylene Gas Released from Chiquita Bananas

“…Before adsorbing ethylene, for the nylon spectra, the typical peaks of the amide group were seen at 1535 cm –1 (amide II, C–N stretch, and CO–N–H bend) and 1637 cm –1 (amide I, CO stretch), those of −NH bending were seen at 3062 cm –1 , and those of −NH stretching were seen at 3286 cm –1 . , The FTIR bands of mordenite exhibited that the intense broad peaks of the Si–O stretching vibration were observed at 1035 cm –1 , and the bands at 1647 cm –1 were attributed to the bending vibration of H–OH. Isolated OH stretching at 3628 cm –1 was assigned to the interaction between the water hydroxyl and cations (Al–OH stretching). , It is noted that the characteristic band for the amide group at 1535 and 1637 cm –1 as well as the −NH vibration band at 3062 and 3286 cm –2 in the FTIR band of nylon-6 was clearly seen in the NMC 30. Furthermore, compared to the mordenite spectra, the stretching vibration peak of Si–O in FTIR bands of the NMC 30 was broadened and shifted to a lower wavenumber from 1035 to 1029 cm –1 .…”

“…Isolated OH stretching at 3628 cm −1 was assigned to the interaction between the water hydroxyl and cations (Al−OH stretching). 16,42 It is noted that the characteristic band for the amide group at 1535 and 1637 cm −1 as well as the −NH vibration band at 3062 and 3286 cm −2 in the FTIR band of nylon-6 was clearly seen in the NMC 30. Furthermore, compared to the mordenite spectra, the stretching vibration peak of Si−O in FTIR bands of the NMC 30 was broadened and shifted to a lower wavenumber from 1035 to 1029 cm −1 .…”

Conversion of Bioethanol to Diethyl Ether Catalyzed by Sulfuric Acid and Zeolite

“…The relative amount of zeolite before and after acid activation can be determined by comparing the intensity of natural zeolite with acid-activated zeolite (1 M H-Zeolite and 6 M H-Zeolite ). XRD results also showed that the zeolite activation process using acid caused an increase in the relative amount of mordenite and clinoptilolite [11].…”

Removal or storage of environmental pollutants and alternative fuel sources with inorganic adsorbents via host–guest encapsulation

“…200 As far as the adsorption of CH4 is concerned, several studies show that other materials such as activated carbon, and metal-organic frameworks (MOFs) typically outperform zeolites. 13,190,191,201 However, some CH4 adsorption studies on natural, ion-exchanged, and acid-treated Turkish zeolite 197 and mordenite 198 revealed that their adsorption capacity depends strongly on the nature of the cation present. Furthermore, the observed capacity values decrease with increasing temperature.…”