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Oxygen-Selective Adsorption in RPM3-Zn Metal Organic Framework
Chemical Engineering Science
  • Cheng Yu Wang
  • Linxi Wang
  • Andrew Belnick
  • Hao Wang
  • Jing I. Li
  • Angela D. Lueking, Missouri University of Science and Technology
Abstract

Development of an oxygen selective adsorbent is anticipated to reduce the material and energy requirements for adsorptive separations of air by a factor of four, due to the relative concentrations of N2 and O2 in air, thereby decreasing the parasitic energy losses, carbon dioxide emissions, and cost of oxygen purification via pressure-swing adsorption. Here, we report that RPM3-Zn (a.k.a. Zn2(bpdc)<2(bpee); bpdc = 4,4'-biphenyldicarboxylate; bpee = 1,2-bipyridylethene) is oxygen selective over nitrogen at temperatures from 77 K to 273 K, although the oxygen capacity of the sorbent decreased markedly at increasing temperatures. Due to an oxygen diffusivity that is ∼1000-fold greater than nitrogen, the effective oxygen selectivity increases to near infinity at low temperature at equal contact times due to N2 mass transfer limitations for gate-opening. The kinetic limitation for N2 to open the structure has a sharp temperature dependence, suggesting this effective kinetic selectivity may be "tuned in" for other flexible metal-organic-frameworks. Although the low temperature oxygen selectivity is not practical to displace cryogenic distillation, the results suggest a new mechanism for tailoring materials for kinetic selectivity, namely, capitalizing upon the delayed opening process for a particular gas relative to another.

Department(s)
Chemical and Biochemical Engineering
Keywords and Phrases
  • Air cleaners,
  • Air purification,
  • Carbon,
  • Carbon dioxide,
  • Crystalline materials,
  • Distillation,
  • Energy dissipation,
  • Global warming,
  • Kinetics,
  • Mass transfer,
  • Nitrogen,
  • Organic polymers,
  • Organometallics,
  • Oxygen,
  • Temperature,
  • Temperature distribution,
  • Zinc,
  • Air separation,
  • Carbon dioxide emissions,
  • Cryogenic distillations,
  • Gate openings,
  • Kinetic selectivity,
  • Mass transfer limitation,
  • Metal organic framework,
  • Pressure swing adsorption,
  • Gas adsorption,
  • Air separation,
  • Kinetic selectivity,
  • RPM3-Zn
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2017 Elsevier, All rights reserved.
Publication Date
6-1-2017
Disciplines
Citation Information
Cheng Yu Wang, Linxi Wang, Andrew Belnick, Hao Wang, et al.. "Oxygen-Selective Adsorption in RPM3-Zn Metal Organic Framework" Chemical Engineering Science Vol. 165 (2017) p. 122 - 130 ISSN: 0009-2509
Available at: http://works.bepress.com/angela-lueking/41/