CN-122028979-A - Carbon molecular sieve monolith and method of making same

Abstract

The method for forming a carbon molecular sieve monolith includes loading a resin into an extruder, heating the resin to form a polymer melt, introducing the polymer melt into a microcapillary film die to form microcapillaries in the polymer melt, quenching the polymer melt to form microcapillary films, creating microcapillary film layers, laminating the layers or placing the microcapillary film layers into a mold, heating the microcapillary film layers to a temperature of 50 ℃ to 350 ℃ to form a polymer monolith, pyrolyzing the polymer monolith by heating the polymer monolith to a temperature of 500 ℃ to 1700 ℃ to form the carbon molecular sieve monolith, and activating the carbon molecular sieve monolith using one or more oxidants.

Inventors

• LIU JUNQIANG
• D.M.Miller
• K.A. Kopi
• J. S. Dickman
• A. W. Schrader
• T.SUN

Assignees

• 陶氏环球技术有限责任公司

Dates

Publication Date

20260512

Application Date

20241015

Priority Date

20231024

Claims (15)

1. 1. A method for forming a carbon molecular sieve monolith, the method comprising: Loading the resin into an extruder; heating the resin to form a polymer melt; introducing the polymer melt into a microcapillary film die to form microcapillaries in the polymer melt; Quenching the polymer melt to form a microcapillary film; generating a microcapillary film layer; Laminating the microcapillary film layer or placing the microcapillary film layer into a mold; Heating the microcapillary film layer to a temperature of 50 ℃ to 350 ℃ to form a polymer monolith; Pyrolyzing the polymer monolith by heating the polymer monolith to a temperature of from 500 ℃ to 1700 ℃ to form the carbon molecular sieve monolith, and The carbon molecular sieve monolith is activated using one or more oxidizing agents.
2. 2. The method of claim 1, wherein the method further comprises stretching the microcapiuary film near the exit of the microcapiuary film die.
3. 3. The method of claim 1 or claim 2, wherein the creating a microcapillary film layer comprises laminating a single microcapillary film on itself.
4. 4. The method of claim 1 or claim 2, wherein the creating the microcapillary film layer comprises stacking a plurality of microcapillary films.
5. 5. The method of any one of claims 1 to 4, wherein the method further comprises cooling the microcapiuary film layer for 1 minute to 48 hours to form a laminate.
6. 6. The method of any one of claims 1-5, wherein the resin comprises polyvinylidene chloride.
7. 7. The method of any one of claims 1-6, wherein heating the resin to form a polymer melt comprises heating the resin to a temperature of 155 ℃ to 170 ℃.
8. 8. The method of any one of claims 1 to 7, wherein the pyrolyzing step comprises heating the polymer monolith to a temperature of 600 ℃ to 1500 ℃.
9. 9. The method of any one of claims 1-8, wherein heating the mold comprising the microcapiuary film comprises heating the mold comprising the microcapiuary film to a temperature of 130 ℃ to 160 ℃.
10. 10. A carbon molecular sieve monolith comprising: A first end and a second end opposite the first end; Two or more sheets of a carbon microcapillary film arranged in parallel such that a first axial end of the two or more sheets of the carbon microcapillary film is positioned at the first end of the carbon molecular sieve monolith and a second axial end of the one or more sheets of the carbon microcapillary film is arranged at the second end of the carbon molecular sieve monolith, and A microcapillary extending from the first end of the one or more sheets of the carbon microcapillary film to the second end of the one or more sheets of the carbon microcapillary film, wherein The outer surfaces of two or more sheets of the carbon microcapillary film are bonded together to form the carbon molecular sieve monolith, and The carbon molecular sieve monolith has a pore density greater than or equal to 300 pores per square inch.
11. 11. The carbon molecular sieve monolith of claim 10, wherein two or more sheets of the carbon microcapiuary film are made of polyvinylidene chloride.
12. 12. The carbon molecular sieve monolith according to any one of claims 10 or 11, wherein the void fraction of the carbon molecular sieve monolith is from 10v.% to 90v.%.
13. 13. The carbon molecular sieve monolith according to any one of claims 10 or 12, wherein the carbon molecular sieve monolith comprises 10 or more sheets of carbon microcapillary film.
14. 14. The carbon molecular sieve monolith according to any one of claims 10 to 13, wherein the carbon molecular sieve monolith has a pore density of 300 pores per square inch to 3000 pores per square inch.
15. 15. The carbon molecular sieve monolith of any one of claims 10 to 14, wherein the adsorbent loading in the carbon molecular sieve monolith is at least 0.1g/cm 3 .

Description

Carbon molecular sieve monolith and method of making same Cross Reference to Related Applications The present application claims the benefit of U.S. provisional application serial No. 63/592,792, filed on 10 months 24 of 2023, the contents of which are incorporated herein in their entirety. Background art. Technical Field The present specification relates generally to carbon molecular sieve monoliths for gas separation. In particular, the present description relates to carbon molecular sieve monoliths for gas separation and methods for preparing carbon molecular sieve monoliths for gas separation. Technical Field Carbon molecular sieves and carbon molecular sieve membranes have been used to separate gases. Carbon molecular sieves can be prepared from various resins that are pyrolyzed at different temperatures and/or under different conditions. Pyrolysis reduces the resin to carbon, but maintains at least some of the porosity in the pyrolysis product in the form of micropores. The carbon molecular sieve thus formed can then be used in conventional gas separation devices (such as packed beds, chromatographic columns, etc.) employing the adsorption of a particular gas, wherein the pore size determines which gas is adsorbed and which gas is not. Separation can be performed using adsorption and desorption techniques alternately, according to, for example, conventional Pressure Swing Adsorption (PSA) or Temperature Swing Adsorption (TSA) methods. Structured adsorbents can use shorter recycle operations to reduce adsorbent bed size and capital costs of PSA without causing pressure drop and mass transfer problems. Thus, there is a need for structured adsorbents and methods for preparing structured adsorbents for gas separation. Disclosure of Invention According to one embodiment, a method for forming a carbon molecular sieve monolith includes loading a resin into an extruder, heating the resin to form a polymer melt, introducing the polymer melt into a microcapillary film die to form microcapillaries in the polymer melt, quenching the polymer melt to form a microcapillary film, creating a microcapillary film layer, laminating the microcapillary film layer or placing the microcapillary film layer into a mold, heating the microcapillary film layer to a temperature of 50 ℃ to 350 ℃ to form a polymer monolith, pyrolyzing the polymer monolith by heating the polymer monolith to a temperature of 500 ℃ to 1700 ℃ to form a carbon molecular sieve monolith, and activating the carbon molecular sieve monolith using one or more oxidants. In another embodiment, a carbon molecular sieve monolith includes a first end and a second end opposite the first end, two or more sheets of a carbon microcapillary film arranged in parallel such that a first axial end of the two or more sheets of the carbon microcapillary film is positioned at the first end of the carbon molecular sieve monolith and a second axial end of the one or more sheets of the carbon microcapillary film is arranged at the second end of the carbon molecular sieve monolith, and microcapillaries extending from the first end of the one or more sheets of the carbon microcapillary film to the second end of the one or more sheets of the carbon microcapillary film, wherein the outer surfaces of the one or more sheets of the carbon microcapillary film are joined together to form the carbon molecular sieve monolith and the pore density of the carbon molecular sieve monolith is greater than or equal to 300 pores per square inch. Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. Drawings FIG. 1 is a schematic diagram of a carbon molecular sieve monolith according to embodiments disclosed and described herein. Fig. 2 is an enlarged photograph of a cross section of a carbon molecular sieve monolith according to embodiments disclosed and described herein. Fig. 3 is an enlarged photograph of a cross section of a carbon molecular sieve monolith according to embodiments disclosed and described herein. FIG. 4 is a graph of capacity of a carbon molecular sieve monolith at various pressures on different dates ac