Study of AgLiLSX for Single-Stage High-Purity Oxygen Production

Ferreira, Daniel; Magalhães, Roberto; Bessa, João; Taveira, Pedro; Sousa, José M.; Whitley, Roger D.; Mendes, Adélio

doi:10.1021/ie500442r

Cited by 20 publications

(27 citation statements)

References 30 publications

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“…Ag-mordenite has been reported as having values of 17% and 0.062 cm 3 g À1 , 28 AgLiLSX has 27% and 0.118 cm 3 g À1 (ref. 61) and Ag-ETS-10 has 38% 31,62 and 0.13 cm 3 g À1 . 63,64 The low porosity of the dipeptides is a contingent property, which does not need to exist in other materials with unidimensional pores, even for such small pores; it stems mostly from the low pore concentration existent in the dipeptides, 0.45 pores nm À2 to 0.48 pores nm À2 .…”

Section: Significance Of Psa Separation In Airmentioning

confidence: 99%

Hydrophobic dipeptide crystals: a promising Ag-free class of ultramicroporous materials showing argon/oxygen adsorption selectivity

Afonso

Mendes

Gales

2014

Phys. Chem. Chem. Phys.

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The adsorption isotherms of nitrogen, oxygen and argon in four VA-class hydrophobic dipeptides are presented. Isotherms were determined at 5, 20 and 35 ºC, for a pressure range of 0-6 bar. Under these conditions, adsorption is still in the Henry region. For all materials and temperatures, the sequence of preferential adsorption is Ar>O2>N2, a highly abnormal result. At 5 ºC, the dipeptide with the smallest pores, VI, has Ar/O2 adsorption equilibrium selectivities up to 1.30, the highest ever measured in Ag -free adsorbents. Gas uptakes, at 1 bar and 20 ºC, are ~0.05 mol·kg -1 , very low relative values that are partially explained by the low porosity of the solids (< 10 %). The significance of these results for the development of new materials for the process of O2 generation by pressure swing adsorption (PSA) is discussed. The results indicate some of the structural and chemical properties that prospective Ag-free adsorbents should have in order to have Ar/O2 selectivity; hydrophobic pores, less than 0.5 nm-wide, and porosity of, at least, 20 %.

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Section: Significance Of Psa Separation In Airmentioning

confidence: 99%

Hydrophobic dipeptide crystals: a promising Ag-free class of ultramicroporous materials showing argon/oxygen adsorption selectivity

Afonso

Mendes

Gales

2014

Phys. Chem. Chem. Phys.

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“…The rise in the number of patents and articles on portable medical oxygen concentrators, specifically by Sircar et al, in the recent years reflects the interest in developing new materials as well as adsorption processes to purify oxygen from air [3][4][5][6][7]. In addition to this, industries such as aerospace, semiconductors, military, and medical require the production of on-site oxygen with ultra-high purity (> 99.5%) [8]. It has been demonstrated that adsorption processes offer more favorable process economics as well as meeting the purity and throughput requirements for small-scale O 2 purification [9].…”

Section: Introductionmentioning

confidence: 99%

Breakthrough dynamics of nitrogen, oxygen, and argon on silver exchanged titanosilicates (Ag-ETS-10)

et al. 2021

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Breakthrough curves of N 2 , O 2 , and Ar on Silver exchanged titanosilicates (Ag-ETS-10) extrudates and granules were measured using a laboratory scale dynamic column breakthrough (DCB) apparatus. In order to investigate the dynamics of the mass transfer, effect of flow rate, temperature and pressure on the composition and temperature curves were studied. In a separate attempt, N 2 breakthrough curves on two columns filled with Ag-ETS-10 extrudates and granules with two different sizes were obtained. Influence of axial-dispersion, macropore, and film resistance within the column was investigated using fundamentals of mass transfer and fluid dynamics which assisted in classifying the dynamics of this separation. The experimental results indicated the rapid mass transfer and the potential for rapid cycles using Ag-ETS-10 for high-purity O 2 production. A fully predictive mathematical model was shown to describe the experimental curves to a high level of precision. Keywords Breakthrough experiment • Oxygen purification • Air separation • Titanosilicates Abbreviations b Parameter in Langmuir isotherm (m 3 mol −1) b 0 Parameter in Langmuir isotherm (m 3 mol −1) c Fluid phase concentration (mol m −3) C pa Specific heat capacity of the adsorbed phase (J mol −1 K −1) C pg Specific heat capacity of the gas phase (J mol −1 K −1) C ps Specific heat capacity of the adsorbent (J kg −1 K −1) C pw Specific heat capacity of the column wall (J kg −1 K −1) d Parameter in dual-site Langmuir isotherm (m 3 mol −1

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“…Many niche applications in medical, semiconductor, military, and aerospace industries require O 2 purities in excess of 95%. ,− For such applications, special sorbents that show oxygen/argon selectivity are required. Very few adsorbents such as carbon molecular sieves, , Ag-mordenite, , Ag-ZSM, and AgLiLSX have been reported to possess this selectivity. Because the properties of O 2 and Ar are very similar, the reported O 2 /Ar selectivities are typically less than 1.29.…”

Section: Introductionmentioning

confidence: 99%

Single- and Dual-Stage High-Purity Oxygen Production Using Silver-Exchanged Titanosilicates (Ag-ETS-10)

Hejazi

Perez

Pai

et al. 2018

Ind. Eng. Chem. Res.

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High-purity (>99.5%) O2 production from air with silver-exchanged titanosilicates (Ag-ETS-10) using multiple single- and dual-stage vacuum swing adsorption (VSA) cycle configurations was investigated through process simulation, and optimization. Model predictions for the Skarstrom cycle were validated through experiments and an O2 purity of 98.3 ± 0.5% with a corresponding recovery of 10.6% was achieved. Oxygen purity-recovery Pareto fronts for the Skarstrom cycle and 6-step cycle with pressure equalization (PE) and heavy product pressurization (HPP) with dry air as the feed were obtained. The optimization predicted 82.0% O2 recovery with a product purity of 99.5% for a 6-step cycle with PE and HPP and dry air feed stream. The effect of nitrogen content in the feed on the performance indicators was also studied. Operating conditions for various cycle configurations were optimized through nondominated sorting genetic algorithm technique to achieve low total energy consumption (592.4 kWh/tonne O2) and high overall productivity (1.30 tonne O2/m3 Ag-ETS-10 day). The Pareto fronts of the single- and dual-stage configurations were compared against each other in order to choose the best possible design. The results indicated that the single-stage 6-step cycle with PE and HPP presents a better performance compared to the other single- and dual-stage approaches. A simple graphical scheduling study was also conducted in order to calculate the number of columns required for a continuous process using the better performing configurations.

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Study of AgLiLSX for Single-Stage High-Purity Oxygen Production

Cited by 20 publications

References 30 publications

Hydrophobic dipeptide crystals: a promising Ag-free class of ultramicroporous materials showing argon/oxygen adsorption selectivity

Hydrophobic dipeptide crystals: a promising Ag-free class of ultramicroporous materials showing argon/oxygen adsorption selectivity

Breakthrough dynamics of nitrogen, oxygen, and argon on silver exchanged titanosilicates (Ag-ETS-10)

Single- and Dual-Stage High-Purity Oxygen Production Using Silver-Exchanged Titanosilicates (Ag-ETS-10)

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