A high effective adsorbent of NOx: Preparation, characterization and performance of Ca-beta zeolites

Chang, Xiaofei; Lu, Guanzhong; Guo, Yun; Wang, Yanqin; Guo, Yanglong

doi:10.1016/j.micromeso.2012.07.040

Cited by 34 publications

(13 citation statements)

References 27 publications

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“…A similar peak for MgZSM-5 was reported by Cai et al [44]. e Ca 2p spectrum of Ca 2.0 DeAlBeta (Figure 8(b)) shows a doublet structure and two peaks with maxima at binding energy 351.7 eV and 348.2 eV corresponding to Ca 2p 1/2 and Ca 2p 3/2 , respectively, and indicates the presence of Ca 2+ species in a different environment [45]. e Sr 3d spectrum of Sr 2.0 DeAlBeta is presented in Figure 8(c).…”

Section: H and 29 Si Mas Nmr)supporting

confidence: 84%

Dealuminated Beta Zeolite Modified by Alkaline Earth Metals

Chałupka

Sadek

Valentin

et al. 2018

Journal of Chemistry

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Alkaline Earth metals (Mg, Sr, and Ca) were incorporated into the dealuminated mesoporous beta zeolite (DeAlBeta) by the two-step postsynthesis method. Physicochemical properties of both unmodified and alkaline Earth metal-modified DeAlBeta zeolite were characterized by XRD, DR UV-vis, FTIR, TPD of NH3 and CO2, NMR, and XPS. The dealumination of beta zeolite led to decrease of its acidity and basicity. The incorporation of alkaline Earth metals into the framework of dealuminated beta zeolite did not affect its structure. The modification of DeAlBeta with a small amount of alkaline Earth metals increases the number of acidic centers, which may be related to the formation of framework Mg (Ca or Sr) (II) Lewis acidic sites.

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Section: H and 29 Si Mas Nmr)supporting

confidence: 84%

Dealuminated Beta Zeolite Modified by Alkaline Earth Metals

Chałupka

Sadek

Valentin

et al. 2018

Journal of Chemistry

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“…There are different methods for removing biuret from urea solution, however practically they are all found in the patent's form. Among these methods, adsorption appears as an alternative [13] of low energy cost (performed at room temperature), simple operation, carried out in simple equipment, and, generally, it presents high adsorption removal efficiency when the technique is applied correctly [14].…”

Section: Introductionmentioning

confidence: 99%

Adsorption as alternative process in the preliminary production of automotive additive

Ventura

Araujo

Guerra

et al. 2020

CI&CEQ

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Nitrogenous contaminants in diesel fraction are converted to NOx compounds in automotive combustion chamber, afterwards they are reduced to nitrogen by catalytic reduction/oxidation reactions in presence of ammonia derived from a 32.5 wt.% urea solution. This process is named selective catalytic reduction (SCR). In Brazil, the urea solution for SCR is ARLA 32 and must comply with the limit content of 0.3 wt.% of biuret. However, the commercial Brazilian urea solution has an average biuret content of 0.5 wt.%. Thus, it is necessary to adjust the biuret content in urea solution to be used as ARLA 32, and adsorption is a low energy option. The objective of this study was to evaluate commercial adsorbents for removing biuret from solution of commercial urea to adjust it to the specification of ARLA 32. Two activated coals and one ion exchange resin were tested in adsorption assays, with best performances of both coals.

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“…NO adsorption in metal-free zeolites (ZSM-5, 13X, SAPO, Y, b, NaY, NaX, CaA, NaA, ferrierite, mordenite, USY, ZSM-22, MCM-22) [26, [49]. After the adsorbent is saturated with NOx, the adsorbed NOx must be desorbed for the adsorbent to be used again.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of NO in clinoptilolite-rich zeolitic mineral by concentration pulse chromatography method

Narin

Ülkü

2016

Microporous and Mesoporous Materials

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a b s t r a c tThe equilibrium and kinetic parameters for NO adsorption in a clinoptilolite-rich natural zeolitic material from Turkey were determined using the concentration pulse chromatography method. Under the experimental conditions (carrier gas velocities and adsorption temperatures) the micropore diffusion resistance was found to be the mass transfer controlling step. Matching the first moment of the response peaks to the mathematical model the Henry's Law constants and heat of adsorption at zero loading were determined. The axial dispersion, external film, macropore and micropore diffusion coefficients, and activation energy for diffusion of NO in the micropores were calculated from the analysis of the second moments of the response peaks. For successive NO pulses without regeneration between the pulses, the retention times of the response peaks decreased and peak areas increased with the injection number indicating irreversible adsorption. The reversibly adsorbed NO could be desorbed by purging with an inert gas at the adsorption pressure and temperature. Temperature programmed desorption profile obtained by heating the NO saturated adsorbent to 400 C under inert flow revealed presence of multiple irreversibly adsorbed species in NZ with different thermal stabilities. Desorption of these species was not achieved during the heating up to 400 C which makes the natural zeolitic materıal suitable for NO storage rather than for cyclic adsorptive separation processes.

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A high effective adsorbent of NOx: Preparation, characterization and performance of Ca-beta zeolites

Cited by 34 publications

References 27 publications

Dealuminated Beta Zeolite Modified by Alkaline Earth Metals

Dealuminated Beta Zeolite Modified by Alkaline Earth Metals

Adsorption as alternative process in the preliminary production of automotive additive

Adsorption of NO in clinoptilolite-rich zeolitic mineral by concentration pulse chromatography method

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