Estimation of the zeolite content of a catalyst from nitrogen adsorption isotherms

Johnson, Marvin F. L.

doi:10.1016/0021-9517(78)90346-9

Cited by 77 publications

(32 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The assessment of specific surface areas (BET and t-plot methods) was performed with N 2 isotherms at 77 K and the zeolite content (wt.%) was determined following the method by Johnson [14]. The zeolite unit cell sizes (UCS) were determined with the ASTM D-3942-91 X-ray diffraction technique, using a Shimadzu XD-1 equipment.…”

Section: Methodsmentioning

confidence: 99%

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Pujro

Falco

Sedrán

2015

Applied Catalysis A: General

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Pujro

Falco

Sedrán

2015

Applied Catalysis A: General

View full text Add to dashboard Cite

“…An error of 5%, mainly from the purification procedure, had already been considered in the zeolite content determinations (Erdem-~enatalar et al 1993). It is also known that X-ray line intensities may not always be proportional to the zeolite contents (Johnson 1978;Valyon et al 1981;Ming and Dixon 1987).…”

Section: Samples In H-formmentioning

confidence: 99%

“…Semiquantitative XRD, for which the calibration curve has to be prepared with a purified zeolite sample, is the most commonly applied technique for this purpose. Making use of the relationships between ion exchange or adsorption performances and zeolite content have been proposed (Johnson 1978;Valyon et al 1981;Sheppard and Gude 1982;Kallo et al 1982;Sersale 1985) as alternatives to the time-consuming, cumbersome and sometimes inaccurate X-ray procedures.…”

Section: Introductionmentioning

confidence: 99%

“…The N2-adsorption capacity measurements that have been used to estimate the zeolite content of synthetic materials (Johnson 1978) are not suitable for natural samples containing zeolites such as clinoptilolite because of the small pore openings in the crystal structure. Valyon et al (1981) have proposed to use the amount of the adsorbate at saturation pressure, calculated from the Dubinin-Astakhov model applied to CO2 adsorption isotherms of the natural samples in their H-forms, as an estimate of the zeolite content.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Estimation of the Zeolite Contents of Tuffaceous Samples from the Bigadiç Clinoptilolite Deposit, Western Turkey

Sirkecioğlu

Erdem-Şenatalar

1996

Clays and clay miner.

View full text Add to dashboard Cite

Abstract--Variation of the NH4+-exchange and CO2-adsorption capacities with zeolite content was investigated in detail to assess the potential use of these capacities for the estimation of the zeolite contents of the samples taken from the Bigadiq clinoptilolite deposit in western Anatolia, as an alternative to the widely used semi-quantitative X-ray diffraction (XRD) technique. Samples with known clinoptilolite contents taken from 2 different zones with fine-and coarse-grained tufts of the Bigadi~ deposit were used for this purpose. Na-enriched forms of the samples were prepared by repeated ion-exchange with NaC1 solutions, and NH4+-forms by repeated Na exchange followed by NH4 § exchange with NH4C1 solutions, which in turn were calcined to obtain the H-forms. NHa+-exchange capacities by Kjeldahl analyses of the NHa+-forms and CO2 adsorption isotherms in the 0 to I00 kPa range of Na-and H-forms of the samples were determined. Dubinin-Astakhov model parameters were calculated from the isotherm data.A strong relationship exists between the experimental CO2-adsorption capacities at 100 kPa of the Na-forms and the zeolite contents of the samples. Although the Dubinin-Astakhov model represented the isotherm data quite well, the relationships between the amounts of adsorbate at saturation pressure, calculated from the model, and the zeolite contents of the samples were weaker. The strength of the relationship between NH4 § exchange capacities and zeolite contents was seen to vary with the zone of origin. There is a very strong relationship between the adsorption and ion-exchange capacities of the samples in their Na-forms taken from the fine-grained zone, indicating that either ion-exchange or adsorption capacity measurements can be used to estimate the zeolite contents of the samples taken from this zone, whereas, significant diffusion hindrance was observed against ion-exchange of hydrated cations from aqueous solutions for some samples from the coarse-grained zone. Inspection of the data pointed to systematic errors in the zeolite contents determined by a semi-quantitative XRD technique. When both zones are considered together, CO2-adsorption capacities at 100 kPa of the samples in their Na-forms can be used as a reliable measure of the zeolite content, which in turn is an important index to predict the performance of natural samples in various applications.

show abstract

“…For a determination of specific surface area of granulated samples, the air-permeability method and the gas adsorption method are generally used [64]. The gas adsorption method is used more widely and can determine the total surface area including cracks and micro pores [65]. By the reasons, the specific surface areas of employed minerals were measured by the Brunauer-Emmett-Teller gas adsorption method [66] which is widely used and useful [34].…”

mentioning

confidence: 99%

Sorption behavior of hydroselenide (HSe⁻) onto iron-containing minerals

Iida

Yamaguchi

Tanaka

2013

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

The sorption behavior of selenium onto iron-containing minerals such as goethite, ferrous oxide, magnetite, and biotite under reducing conditions were investigated by batch sorption experiments. Selenium was spiked as HSe − and Se 4 2− in the experimental solutions and reducing conditions were maintained throughout the sorption periods. The sorption behaviors of HSe − were analyzed by the triple-layer surface complexation model with the Visual Minteq computer program. The sorption data and the model calculations suggested that the dominant sorption mechanisms of HSe − were inner-sphere surface complexation for goethite and ferrous oxide but outer-sphere surface complexation for magnetite and biotite. The intrinsic equilibrium constant of the inner-sphere surface complexation reaction of HSe − with goethite, logK int HSe = 6.0, was determined by the fitting to the experimental results. The value of the equilibrium constant for outer-sphere complexation for magnetite and biotite was estimated to be around 12.

show abstract

Estimation of the zeolite content of a catalyst from nitrogen adsorption isotherms

Cited by 77 publications

References 5 publications

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Estimation of the Zeolite Contents of Tuffaceous Samples from the Bigadiç Clinoptilolite Deposit, Western Turkey

Sorption behavior of hydroselenide (HSe⁻) onto iron-containing minerals

Contact Info

Product

Resources

About

Estimation of the zeolite content of a catalyst from nitrogen adsorption isotherms

Cited by 77 publications

References 5 publications

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Formation of aromatics in heavy gasoline and light LCO ends in FCC

Estimation of the Zeolite Contents of Tuffaceous Samples from the Bigadiç Clinoptilolite Deposit, Western Turkey

Sorption behavior of hydroselenide (HSe−) onto iron-containing minerals

Contact Info

Product

Resources

About

Sorption behavior of hydroselenide (HSe⁻) onto iron-containing minerals