“…Clinoptilolite possesses the exceptional physical properties, which it owes to its two-dimensional structure [46]. Additionally, exhibits high mechanical crush strength (more than 7 MPa), which is crucial for its stability during the majority of catalytic reactions [47]. Because of the physicochemical properties of clinoptilolite, obtaining a catalyst that is based on this zeolite requires two-or threestep modification, such as ion-exchange and calcination.…”
Natural zeolite of the heulandite-type framework was modified with iron and tested as a catalyst for the selective catalytic reduction of nitrogen oxides with ammonia (NH3-SCR) in the temperature range of 150–450 °C. The catalyst was prepared at a laboratory scale in a powder form and then the series of experiments of its shaping into tablets was conducted. Physicochemical studies of the catalyst (N2 sorption at −196 °C, FT-IR, XRD, UV-vis) were performed to determine the textural and structural properties and identify the surface functional groups, the crystalline structure of the catalysts and the form and aggregation of the active phase. The activity tests over the shaped catalyst were performed industry-reflecting conditions, using tail gases from the pilot nitric acid plant. The influence of a temperature, catalyst load, and the amount of reducing agent (ammonia) on the NOx reduction process were investigated. The results of catalytic tests that were performed on model gas mixture showed that non-modified clinoptilolite exhibited around 58% conversion of NO at 450 °C. The temperature window of the shaped catalyst shifted to a higher temperature range in comparison to the powder sample. The catalytic performance of the shaped Fe-clinoptilolite in the industry-reflecting conditions was satisfactory, especially at 450 °C. Additionally, it was observed that the ratio of N2O concentration downstream and upstream of the catalytic bed was below 1, which indicated that the catalyst exhibited activity in both DeNOx and DeN2O process.
“…Clinoptilolite possesses the exceptional physical properties, which it owes to its two-dimensional structure [46]. Additionally, exhibits high mechanical crush strength (more than 7 MPa), which is crucial for its stability during the majority of catalytic reactions [47]. Because of the physicochemical properties of clinoptilolite, obtaining a catalyst that is based on this zeolite requires two-or threestep modification, such as ion-exchange and calcination.…”
Natural zeolite of the heulandite-type framework was modified with iron and tested as a catalyst for the selective catalytic reduction of nitrogen oxides with ammonia (NH3-SCR) in the temperature range of 150–450 °C. The catalyst was prepared at a laboratory scale in a powder form and then the series of experiments of its shaping into tablets was conducted. Physicochemical studies of the catalyst (N2 sorption at −196 °C, FT-IR, XRD, UV-vis) were performed to determine the textural and structural properties and identify the surface functional groups, the crystalline structure of the catalysts and the form and aggregation of the active phase. The activity tests over the shaped catalyst were performed industry-reflecting conditions, using tail gases from the pilot nitric acid plant. The influence of a temperature, catalyst load, and the amount of reducing agent (ammonia) on the NOx reduction process were investigated. The results of catalytic tests that were performed on model gas mixture showed that non-modified clinoptilolite exhibited around 58% conversion of NO at 450 °C. The temperature window of the shaped catalyst shifted to a higher temperature range in comparison to the powder sample. The catalytic performance of the shaped Fe-clinoptilolite in the industry-reflecting conditions was satisfactory, especially at 450 °C. Additionally, it was observed that the ratio of N2O concentration downstream and upstream of the catalytic bed was below 1, which indicated that the catalyst exhibited activity in both DeNOx and DeN2O process.
“…Besides, a gas chromatography (SHIMADZU model 2010 plus) is employed for determining of nitrous oxide quantity in effluent. More data can be found in the previous literature [40] . Fig.…”
Section: Methodsmentioning
confidence: 96%
“…The performance of the samples was assessed utilizing an integral catalytic reactor illustrated in Fig. 1 [40] . In short, the inlet gas comprise a admixture with nitric oxide (30 ppm), nitrogen dioxide (460 ppm), oxygen (2.5 vol%), C 3 H 8 (1000) ppm and also Argon gas (balance).…”
“…A CLP impregnated with Co was used for direct decomposition of N 2 O, a greenhouse gas (Ghahri et al , 2017). A protonated CLP showed a promising performance for NO x abatement via selective catalytic reduction by propane (Ghasemian et al , 2014). The performance of zero-valent Fe 0 -coated CLP in the chemical reduction of NO 3 – in unbuffered conditions was enhanced by coating small amounts of Cu 0 onto the freshly prepared Fe 0 /zeolite composite (Fateminia & Falamaki, 2013).…”
Section: Research Production and Applications Of Natural Iranian Zeomentioning
confidence: 99%
“…Some Iranian natural CLP zeolites have displayed catalytic properties in different systems such as methanol and ethanol/bioethanol dehydration (Karimi et al , 2016) and as catalyst supports for liquid-phase cation reduction and para-nitrophenol hydrogenation (Ghasemian et al , 2014). CLP nanopowders (<100 nm) of desirable crystal order were produced by application of appropriate wet and dry ball-milling.…”
Section: Research Production and Applications Of Natural Iranian Zeomentioning
Iran has significant deposits of high-purity natural zeolites. Many Iranian scholars conduct scientific research on porous materials, from natural and synthetic zeolites to metal organic framework materials. Iranian zeolite deposits and associated research are reviewed here. Various industrial applications of natural zeolites, from agriculture to animal husbandry to the construction industry and beyond are discussed here.
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