Regenerable VOC filters with improved selectivity and efficacy

Patent metadata

Field	Value
Publication number	US-12318753-B2
Application number	US-202017774430-A
Country	US
Kind code	B2
Filing date	Nov 4, 2020
Priority date	Nov 4, 2019
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

The present invention relates, inter alia, to the use of porous crystalline solids constituted of a metal-organic framework (MOF) for the selective adsorption of aldehyde volatile organic compounds.
The MOF solids of the present invention can be used for the improved purification of dry or humid air, and for the manufacture of regenerable filters for air purification, particularly leak-free regenerable air filters.

First claim

The invention claimed is:

1. Process for purifying a gaseous environment, by selective adsorption of aldehyde volatile organic compounds (VOCs) from the gaseous environment over non-aldehyde VOCs, comprising the step of contacting the gaseous environment to be purified with a porous water-stable Metal-Organic Framework (MOF) material, wherein the MOF material comprising an average pore size <40 {acute over (Å)} and a hydrophilic core formed by basic groups and hydrogen-bond accepting or donating oxygenated species in the MOF material, wherein the basic groups are covalently bound to the MOF material without binding to the metal sites of the MOF material, wherein the ligands in the MOF material are N-containing heterocyclic ligands having available at least one of the basic groups embedded within the ligand itself not involved in binding to the metal sites of the MOF material and wherein the crystal structure of the MOF material, as measured by X-Ray diffraction pattern or IR spectroscopy, and average pore size, as calculated by the nitrogen adsorption/desorption isotherm method at −196° C. under 105 Pa, remain unchanged within experimental error, after being exposed to a gaseous environment with 50% relative humidity (RH) for 24 hours at 100° C. and atmospheric pressure, or after being placed in water at 100° C. for 12 hours.

2. The process according to claim 1 , wherein the MOF material is alone or mixed with other porous materials such as other MOFs, zeolites, and/or activated carbon.

3. The process according to claim 1 , wherein the MOF material is comprised in a filter for air purification.

4. The process according to claim 3 , wherein the filter is leak-free with respect to aldehyde volatile organic compounds present in air at a concentration in the order of 1 ppb and 500 ppm when the contaminated air flow through the filter at a space velocity≤60000 h-1 and retains 100% of the aldehyde(s) adsorbed under atmospheric pressure and under a working temperature in the range 10 to 50° C.

5. The process according to claim 4 , wherein the filter is regenerable by thermodesorption at low temperature of the filter to ≥75% of its adsorption/filtering capacity, wherein the process comprises at least one regeneration cycle, by heating said filter to a temperature ≥70° C.

6. The process according to claim 4 , wherein the filter is regenerable to ≥75% of its adsorption/filtering capacity, wherein the process comprises at least one regeneration cycle, by cleaning with water and/or a hydroalcoholic solution at room temperature.

7. The process according to claim 1 , wherein the metal atom of the MOF material is selected from Sc, Y, Tb, Gd, Ce, Ln, La, Ti, Zr, Fe, Al or Cr.

8. The process according to claim 1 , wherein N-containing heterocyclic ligands are present in the MOF material in the form of N-heterocyclic polycarboxylate ligands.

9. The process according to claim 1 , wherein the hydrogen-bond accepting or donating oxygenated species in the MOF material are present in the form of oxo-clusters, oxo-hydroxo clusters, and/or OH.

10. The process according to claim 1 , wherein the MOF material has a crystalline structure selected from UiO-66, MIL-53, MIL-68, MIL-125, MIL-101, CAU-10, MIL-160, PDA-type MOF materials.

11. The process according to claim 1 , wherein the MOF material is selected from Al-3,5-PDA (“MOF-303”), DUT-67 (Zr)-PZDC, CAU-10 (Al)-pyridine, CAU-10 (Al)-pyrazine or a mixture of two or more of the above.

12. The process according to claim 4 , wherein the filter is comprised in a system for air purification.

13. The process according to claim 1 , wherein the MOF material has been coated on a support in the form of a plate, a honeycomb shaped support, a grid, or any shape used in air purification filters, or on a support with filtering capacities.

14. The process according to claim 13 , wherein the MOF material is in the form of a shaped body.

15. The process according to claim 14 , wherein the MOF material is made into a shaped body using binders, lubricants or other additives conventionally used in the preparation of adsorbent shaped bodies.

16. The process according to claim 14 , wherein the shaped MOF material is contained in the cavities of a hollow support.

17. The process according to claim 13 , further comprising a step of soaking the MOF material in water and/or a hydro alcoholic solution at room temperature for a suitable amount of time.

18. The process according to claim 13 , wherein the air is an indoor air.

Assignees

• Ecole Nat Superieure Dingenieurs De Caen
• Univ Caen
• Centre Nat Rech Scient
• Ecole Superieure Physique & Chimie Ind Ville De Paris
• Ecole Normale Superieure De Paris
• Teqoya Sas
• Centre National De La Racherche Scient

Inventors

• Daturi Marco
• Guitton Pierre
• Nouar Farid
• Sadovnik Nicolas
• Serre Christian

Classifications

• B01J20/3475

  in the liquid phase · CPC title

• B01J20/28083

  being in the range 2-50 nm, i.e. mesopores · CPC title

• B01J20/28045

  Honeycomb or cellular structures; Solid foams or sponges · CPC title

• B01J20/20

  comprising free carbon; comprising carbon obtained by carbonising processes · CPC title

• B01J20/18

  Synthetic zeolitic molecular sieves · CPC title