Search

US-20260124579-A1 - HONEYCOMB STRUCTURE AND METHOD FOR PRODUCING SAME

US20260124579A1US 20260124579 A1US20260124579 A1US 20260124579A1US-20260124579-A1

Abstract

A honeycomb structure comprising a plurality of cell channels that pass through an interior of the honeycomb structure and are partitioned by partition walls, wherein the partition walls comprise a solid organic compound having an amino group, an organic binder, and an inorganic binder.

Inventors

  • Mitsuharu Ono
  • Takuya Nakashima
  • Koji MOTOKI
  • Shungo Nagai
  • Hiroyuki Suenobu
  • Koji Fukuyo
  • Hideyuki TOYOSHIMA
  • Masataka Yamashita

Assignees

  • NGK INSULATORS, LTD.

Dates

Publication Date
20260507
Application Date
20260105

Claims (20)

  1. 1 . A honeycomb structure comprising: a plurality of cell channels that pass through an interior of the honeycomb structure and are partitioned by partition walls, wherein the partition walls comprise a solid organic compound having the amino group, an organic binder, and an inorganic binder.
  2. 2 . The honeycomb structure according to claim 1 , wherein the solid organic compound having the amino group is water-insoluble.
  3. 3 . The honeycomb structure according to claim 1 , wherein a content of the solid organic compound having the amino group in the partition walls is 40 to 94% by mass, a content of the inorganic binder in the partition walls is 3 to 50% by mass, and a content of the organic binder in the partition walls is 3 to 20% by mass.
  4. 4 . The honeycomb structure according to claim 1 , wherein a content of the solid organic compound having the amino group in the partition walls is 40 to 90% by mass, a content of the inorganic binder in the partition walls is 5 to 35% by mass, and a content of the organic binder in the partition walls is 5 to 10% by mass.
  5. 5 . The honeycomb structure according to claim 1 , wherein the solid organic compound having the amino group is a weakly basic anion exchange resin having the amino group.
  6. 6 . The honeycomb structure according to claim 1 , wherein the solid organic compound having the amino group comprises one or more selected from a styrene-based divinylbenzene polymer having the amino group and an acrylic-based divinylbenzene polymer having the amino group.
  7. 7 . The honeycomb structure according to claim 1 , wherein the solid organic compound having the amino group comprises a primary amine as a functional group.
  8. 8 . The honeycomb structure according to claim 1 , wherein the solid organic compound having the amino group comprises an aromatic ring.
  9. 9 . The honeycomb structure according to claim 1 , wherein the inorganic binder comprises one or more inorganic binders selected from fibrous and granular inorganic binders.
  10. 10 . The honeycomb structure according to claim 1 , wherein the inorganic binder comprises one or more inorganic binders selected from clay, diatomaceous earth, layered clay minerals, montmorillonite, hydrotalcite, activated clay, acid clay, hectorite, halloysite, attapulgite, silica, alumina, talc, chlorite, vermiculite, mica, illite, pyrophyllite, sericite, kaolin, sepiolite, boehmite, palygorskite, bentonite, colloidal silica and alumina sol.
  11. 11 . The honeycomb structure according to claim 10 , wherein the inorganic binder comprises one or more selected from sepiolite, boehmite, bentonite, silica, kaolin, and talc.
  12. 12 . The honeycomb structure according to claim 11 , wherein the inorganic binder comprises sepiolite.
  13. 13 . A method for producing a honeycomb structure, comprising: a step of kneading a forming raw material comprising a solvent, a solid organic compound having an amino group, an organic binder, and an inorganic binder to prepare a green body; and a step of forming a honeycomb structure from the green body, the honeycomb structure having a plurality of cell channels that pass through an interior of the honeycomb structure and are partitioned by partition walls.
  14. 14 . The method according to claim 13 , wherein the solid organic compound having the amino group is water-insoluble.
  15. 15 . The method according to claim 13 , wherein a content of the solid organic compound having the amino group in the forming raw material excluding the solvent is 40 to 94% by mass, a content of the inorganic binder in the forming raw material excluding the solvent is 3 to 50% by mass, and a content of the organic binder in the forming raw material excluding the solvent is 3 to 20% by mass.
  16. 16 . The method according to claim 13 , wherein a content of the solid organic compound having the amino group in the forming raw material excluding the solvent is 40 to 90% by mass, a content of the inorganic binder in the forming raw material excluding the solvent is 5 to 35% by mass, and a content of the organic binder in the forming raw material excluding the solvent is 5 to 10% by mass.
  17. 17 . The method according to claim 13 , wherein the solid organic compound having the amino group is a weakly basic anion exchange resin having the amino group.
  18. 18 . The method according to claim 13 , wherein the solid organic compound having the amino group comprises one or more selected from a styrene-based divinylbenzene polymer having the amino group and an acrylic-based divinylbenzene polymer having the amino group.
  19. 19 . The method according to claim 13 , wherein the solid organic compound having the amino group comprises a primary amine as a functional group.
  20. 20 . The method according to claim 13 , wherein the solid organic compound having the amino group comprises an aromatic ring.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present invention claims the benefit of priority to International Application PCT/JP2023/27070 filed on Jul. 24, 2023 with the Japanese Patent Office, the entire contents of which are incorporated herein by reference in its entirety. FIELD OF THE INVENTION The present invention is related to a honeycomb structure and a method for producing the same. More particularly, the present invention is related to a honeycomb structure having a CO2 adsorption capability and a method for producing the same. BACKGROUND OF THE INVENTION In order to realize a decarbonized society, there is a growing need for technology to capture and utilize carbon dioxide (CO2) from the atmosphere and exhaust gases. A typical conventional CO2 capture technology that has been developed is a technology for adsorbing CO2 in the atmosphere (DAC: Direct Air Capture). There are several types of DAC, including liquid absorption method, membrane separation method, and solid adsorption method. In the solid adsorption method, CO2 adsorption (absorption) material is generally supported on a substrate. As a substrate to be used in the solid adsorption method, a honeycomb structure is expected to be used, which has a proven track record in purifying automobile exhaust gases. Conventional honeycomb structures have generally been produced by kneading a forming raw material containing ceramic raw materials, water, a binder, and the like to obtain a green body, extrusion molding the resulting green body to prepare a honeycomb formed body, and then subjecting the honeycomb formed body to a heat treatment such as firing (Patent Literature 1). However, heat treatments such as firing require a large amount of energy and often involve the combustion of hydrocarbon fuels, which generates CO2. Furthermore, if an organic binder is used as the binder, further CO2 is generated by combustion during firing. Patent Literature 2 describes a honeycomb ceramic substrate for CO2 capture. This honeycomb ceramic substrate for CO2 capture comprises a honeycomb ceramic substrate having porous partition walls, a plurality of inorganic support particles within at least one pore of the porous partition walls, and an organic carbon dioxide adsorbent supported by at least one of the inorganic support particles. This honeycomb ceramic substrate for CO2 capture is produced through high temperature heat treatment. Specifically, the honeycomb ceramic substrate obtained through the forming and firing processes is contacted with a support precursor slurry, calcined at a temperature of about 100° C. to about 600° C. for about 1 hour to about 10 hours, contacted with an organic CO2 adsorbent, and then dried at a temperature of about 50° C. to about 100° C. to produce the honeycomb ceramic substrate. Under the above-mentioned background technology, a technique for producing a honeycomb structure without firing is also known. Patent Literature 3 describes a honeycomb substrate having a plurality of partition walls extending axially from an inlet end to an outlet end, thereby forming a plurality of flow channels, the honeycomb substrate comprising a mixture of inorganic powder components and an organic binder, and an amine polymer having functional structural unit groups capable of absorbing CO2 dispersed in the inorganic powder components of the partition walls of the honeycomb substrate. The honeycomb substrate is formed by a method that includes dry blending inorganic oxide powder components and an organic binder into a mixture; adding a solution of an amine polymer and a solvent to the mixture to form a precursor; kneading the precursor; extrusion molding the kneaded precursor to form an interconnected monolith having a plurality of partition walls extending axially from an inlet end to an outlet end thereby forming a plurality of flow channels; and drying to remove the solvent from the interconnected monolith to form an absorbent structure for CO2 capture. PRIOR ART Patent Literature [Patent Literature 1] Japanese Patent Application Publication No. 2020-019690[Patent Literature 2] Japanese Patent Application Publication No. 2018-538137[Patent Literature 3] Japanese Patent Application Publication No. 2015-508018 SUMMARY OF THE INVENTION The honeycomb substrate described in Patent Literature 3 uses an amine polymer and has a functional structural unit group that absorbs CO2, making it possible to capture CO2. Further, since the honeycomb substrate is produced without undergoing a firing process that requires high heating temperatures, it is possible to reduce CO2 emissions during producing. However, the honeycomb substrate described in Patent Literature 3 uses an amine polymer, which is easily dissolved in water. Furthermore, many of the organic binders that remain when the material is not fired are water-soluble. For this reason, the honeycomb substrate described in Patent Literature 3 has room for improvement in terms of water resistance. The