Separation of Xylene Isomers: A Review of Recent Advances in Materials

Purification of the C8 aromatics (xylenes and ethylbenzene) is particularly challenging because of their similar physical properties. It is also relevant because of their industrial utility. Physisorptive separation of C8 aromatics has long been suggested as an energy efficient solution but no physisorbent has yet combined high selectivity (>5) with high adsorption capacity (>50 wt %). Now a counterintuitive approach to the adsorptive separation of o‐xylene from other C8 aromatics involves the study of a known nonporous layered material, [Co(bipy)2(NCS)2]n (sql‐1‐Co‐NCS), which can reversibly switch to C8 aromatics loaded phases with different switching pressures and kinetics, manifesting benchmark o‐xylene selectivity (SOX/EB≈60) and high saturation capacity (>80 wt %). Structural insight into the observed selectivity and capacity is gained by analysis of the crystal structures of C8 aromatics loaded phases.

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“…10-20 wt %) and selectivity (ca. 5), [5] overshadowing their advantages of low cost and ready availability.…”

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confidence: 99%

Highly Selective, High‐Capacity Separation of o‐Xylene from C₈ Aromatics by a Switching Adsorbent Layered Material

et al. 2019

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“…DPX serves as a representative substance for relevant applications (e.g., supercapacitors and filtering), since its molecule size is more comparable to common organic electrolytes such as tetrahydrofuran [58], acetonitrile [59], ethylene carbonate [60], propylene carbonate [61] and ionic liquids [1] in contrast to argon. Furthermore, the adsorption of xylene isomers is an important step for synthesizing polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) [62]. Moreover, Ar physisorption measurements are conducted at 87 K, which is a less suitable temperature for applications compared to DPX adsorption measurements at 286 K.…”

Section: Resultsmentioning

confidence: 99%

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

Badaczewski¹,

Loeh²,

Pfaff³

et al. 2020

Beilstein J. Nanotechnol.

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This study is dedicated to link the nanoscale pore space of carbon materials, prepared by hard-templating of meso-macroporous SiO 2 monoliths, to the corresponding nanoscale polyaromatic microstructure using two different carbon precursors wthat generally exhibit markedly different carbonization properties, i.e., a graphitizable pitch and a non-graphitizable resin. The micro-and mesoporosity of these monolithic carbon materials was studied by the sorption behavior of a relatively large organic molecule (p-xylene) in comparison to typical gas adsorbates (Ar). In addition, to obtain a detailed view on the nanopore space small-angle neutron scattering (SANS) combined with in situ physisorption was applied, using deuterated p-xylene (DPX) as a contrast-matching agent in the neutron scattering process. The impact of the carbon precursor on the structural order on an atomic scale in terms of size and disorder of the carbon microstructure, on the nanopore structure, and on the template process is analyzed by special evaluation approaches for SANS and wide-angle X-ray scattering (WAXS). The WAXS analysis shows that the pitch-based monolithic material exhibits a more ordered microstructure consisting of larger graphene stacks and similar graphene layer sizes compared to the monolithic resin. Another major finding is the discrepancy in the accessible micro/mesoporosity between Ar and deuterated p-xylene that found for the two different carbon precursors, pitch and resin, which can be regarded as representative carbon precursors in general. These differences essentially indicate that physisorption using probe gases such as Ar or N 2 can provide misleading parameters if to be used to appraise the accessibility of the nanoscale pore space.

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“…The xylene isomers, namely, p ‐xylene, m ‐xylene, and o ‐xylene, with two methyl groups at different positions of a benzene ring are mostly generated from the catalytic reforming of crude oils . Each isomer acts as the valuable intermediate with broad applications in chemical industry.…”

Section: Important Separation Systemmentioning

confidence: 99%

Membrane Separation in Organic Liquid: Technologies, Achievements, and Opportunities

et al. 2018

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Membrane technology is one of the most promising technologies for separation and purification that is routinely and commercially employed in aqueous solutions. In comparison, its applications in organic solvents are severely underdeveloped mainly due to the poor stability of traditional polymer membranes in organic solvents. The emerging materials such as crosslinked polymers, covalent organic frameworks, metal–organic frameworks, conjugated microporous polymers, carbon molecular sieves, and graphene provide the solutions to address this problem. The membranes constructed with these novel materials show outstanding separation performance in regard to both high selectivity and solvent permeability, greatly pushing forward utilization of membrane technology in organic media. Here, an overview of the most important organic mixtures that need to be separated, the major separation processes adopted nowadays in organic solvents, and the recent progress in new developed membranes is provided.

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Separation of Xylene Isomers: A Review of Recent Advances in Materials

Cited by 186 publications

References 181 publications

Highly Selective, High‐Capacity Separation of o‐Xylene from C₈ Aromatics by a Switching Adsorbent Layered Material

Highly Selective, High‐Capacity Separation of o‐Xylene from C₈ Aromatics by a Switching Adsorbent Layered Material

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

Membrane Separation in Organic Liquid: Technologies, Achievements, and Opportunities

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Separation of Xylene Isomers: A Review of Recent Advances in Materials

Cited by 186 publications

References 181 publications

Highly Selective, High‐Capacity Separation of o‐Xylene from C8 Aromatics by a Switching Adsorbent Layered Material

Highly Selective, High‐Capacity Separation of o‐Xylene from C8 Aromatics by a Switching Adsorbent Layered Material

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

Membrane Separation in Organic Liquid: Technologies, Achievements, and Opportunities

Contact Info

Product

Resources

About

Highly Selective, High‐Capacity Separation of o‐Xylene from C₈ Aromatics by a Switching Adsorbent Layered Material

Highly Selective, High‐Capacity Separation of o‐Xylene from C₈ Aromatics by a Switching Adsorbent Layered Material