Composite adsorbent for separation of ethylbenzene by adsorption distillation and application thereof

Patent metadata

Field	Value
Publication number	US-12441672-B2
Application number	US-202118042312-A
Country	US
Kind code	B2
Filing date	Aug 24, 2021
Priority date	Aug 26, 2020
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A composite adsorbent for separating ethylbenzene from C8 arene by an adsorption distillation contains 1-50 mass % of a xylene adsorbent and 50-99 mass % of a carrier liquid. The carrier liquid is selected from one or two of alkane, aryl-substituted alkane, decalin and alkyl-substituted decalin. The alkane is C10-C26 alkane, and the aryl-substituted alkane is C13-C16 aryl-substituted alkane. The composite adsorbent can increase the volatility of ethylbenzene relative to other C8 arenes and thus can separate a high-purity ethylbenzene from C8 arene by the adsorption distillation.

First claim

The invention claimed is:

1. A composite adsorbent for separating ethylbenzene from C 8 arene by adsorption distillation, comprising 1-50 mass % of a xylene adsorbent and 50-99 mass % of a carrier liquid,
wherein the carrier liquid is selected from alkane, aryl-substituted alkane, decalin, alkyl-substituted decalin, and a combination of two thereof, wherein the alkane is C 10 -C 26 alkane, and the aryl-substituted alkane is C 13 -C 16 aryl-substituted alkane,
wherein the xylene adsorbent, prior to being mixed with the carrier liquid, is a Y molecular sieve powder having supported thereon ions of Group IA metals, Group IIA metals, or both,
wherein the Y molecular sieve powder has a grain size of 0.1 to 2 microns, and
wherein the xylene adsorbent flows with the carrier liquid during operation.

2. The composite adsorbent according to claim 1 , wherein the composite adsorbent includes 5-35 mass % of the xylene adsorbent and 65-95 mass % of the carrier liquid.

3. The composite adsorbent according to claim 1 , wherein the xylene adsorbent is a NaY molecular sieve.

4. The composite adsorbent according to claim 1 , wherein the alkane is C 10 -C 24 n-alkane; the aryl-substituted alkane is C 13 -C 16 diphenyl alkane; the alkyl of the alkyl-substituted decalin is C 1 -C 12 alkyl and the number of the substituting alkyl is 1-4.

5. The composite adsorbent according to claim 4 , wherein the alkane is C 11 -C 20 n-alkane; and the alkyl of the alkyl-substituted decalin is C 3 -C 10 alkyl.

6. A method for separating ethylbenzene by adsorption distillation, comprising:
introducing a C 8 arene mixture into a middle part of an adsorption distillation column;
introducing the composite adsorbent of claim 1 into an upper part of the adsorption distillation column;
after the adsorption distillation, withdrawing ethylbenzene from the top of the adsorption distillation column;
withdrawing the composite adsorbent enriched with xylene from the bottom of the column and feeding it to a middle part of a distillation desorption column; and
after a distillation desorption, withdrawing a mixed xylene from the top of the distillation desorption column, obtaining a regenerated composite adsorbent at the bottom of the distillation desorption column and feeding it to the upper part of the adsorption distillation column.

7. The method according to claim 6 , wherein an overhead pressure of the adsorption distillation column is 0.01-0.2 MPa; a theoretical plate number is 30-100; the composite adsorbent enters the column at a temperature of 90-130° C.; and a column bottom temperature is 140-250° C.

8. The method according to claim 7 , wherein a mass ratio of the xylene adsorbent in the composite adsorbent entering the adsorption distillation column to the C 8 arene mixture is 1.5 to 6; a mass ratio of the carrier liquid to the xylene adsorbent is 1.5 to 20; and a reflux ratio is 1 to 15.

9. The method according to claim 6 , wherein an overhead pressure of the distillation desorption column is 0.01-0.15 MPa; a theoretical plate number is 20-50; and a bottom temperature is 160-280° C.

10. The method according to claim 9 , wherein a reflux ratio of the distillation desorption column is 0.3-3.

11. The method according to claim 6 , wherein the content of ethylbenzene in the C 8 arene mixture is 10-85 mass %.

12. The composite adsorbent according to claim 1 , wherein the carrier liquid has a boiling point of higher than 180° C.

Assignees

• China Petroleum & Chem Corp
• Sinopec Res Inst Petroleum

Inventors

• Qie Siyuan
• Tang Wencheng
• Zhao Ming
• Tian Longsheng
• Gao Siliang
• Pang Weiwei

Classifications

• B01J20/28004

  Sorbent size or size distribution, e.g. particle size · CPC title

• B01J20/22

  comprising organic material · CPC title

• B01J20/186

  Chemical treatments in view of modifying the properties of the sieve, e.g. increasing the stability or the activity, also decreasing the activity · CPC title

• B01D3/34

  with one or more auxiliary substances · CPC title

• B01D3/32

  Other features of fractionating columns {; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30} · CPC title