RECOVERY OF GASES, ESPECIALLY PERMANENT GASES, FROM STREAMS OF MATTER, ESPECIALLY FROM OFFGAS STREAMS FROM POLYMERIZATIONS

• US 20170209830A1
• Filed: 07/23/2015
• Published: 07/27/2017
• Est. Priority Date: 08/07/2014
• Status: Active Grant

• Current Assignee: Linde AG (Linde Plc)
• Original Assignee: Linde AG (Linde Plc)
• Inventors: Leitmayr, Werner, Witzleb, Volker, Voss, Christian, Tota, Akos, Bauer, Martin
• Granted Patent: US 10,092,876 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2257/102 Nitrogen
• CPC Class Codes: B01D 2257/108 Hydrogen
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: B01D 53/229 Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
• CPC Class Codes: C07C 11/04 Ethylene
• CPC Class Codes: C07C 11/06 Propene
• CPC Class Codes: C07C 7/005 Processes comprising at least two steps in series
• CPC Class Codes: C07C 7/12 by adsorption, i.e. purification or separation of hydrocarbons with the aid of solids, e.g. with ion-exchangers
• CPC Class Codes: C07C 7/144 using membranes, e.g. selective permeation

Abstract

A method of cleaning a stream of matter that includes a C2+ fraction and a first gaseous substance and a second gaseous substance. The stream of matter is subjected to a pressure swing adsorption to remove the C2+ fraction by means of a membrane to obtain a retentate and a permeate. The first substance is enriched in retentate and depleted in permeate and the second substance is depleted in retentate and enriched in permeate.

Claims

1. A method of cleaning a stream of matter, wherein the stream of matter includes a C₂₊ fraction and at least one first gaseous substance and a different second gaseous substance, wherein the stream of matter is subjected to a pressure swing adsorption to remove the C₂₊ fraction,

characterized in that

the stream of matter, after removal of the C₂₊ fraction by means of a membrane, is separated into a retentate and a permeate, wherein the first substance is enriched in the retentate and the second substance is depleted in the retentate, and wherein the first substance is depleted in the permeate and the second substance is enriched in the permeate.

3. The method as claimed in claim 1, characterized in that the membrane includes at least one of the following substances or is formed from at least one of the following substances:

polysulfone, polyether sulfone, polyimide, polyamide.

4. The method as claimed in claim 1, characterized in that the stream of matter is an offgas stream.

5. The method as claimed in claim 1, characterized in that the stream of matter is obtained in a process conducted upstream of the pressure swing adsorption.

6. The method as claimed in claim 5, characterized in that the retentate is recycled into the process.

7. The method as claimed in claim 5, characterized in that the process comprises a polymerization, wherein the stream of matter is obtained as offgas stream of the polymerization, especially by purging a polymer produced by polymerization with a gas stream to obtain that stream of matter as offgas stream.

8. The method as claimed in claim 1, characterized in that the C₂₊ fraction includes ethylene or propylene.

9. The method as claimed in claim 1, characterized in that the first substance is nitrogen.

10. The method as claimed in claim 1, characterized in that the second substance is hydrogen.

11. The method as claimed in claim 1, characterized in that the permeate combusted or utilized in some other way.

2. The method as claimed in claim 2, characterized in that the first and second substance are selected from the group comprising hydrogen, nitrogen, methane, carbon monoxide and carbon dioxide.