Method for regenerating adsorbent media used for extracting natural gas liquids from natural gas

Patent metadata

Field	Value
Publication number	US-2016355743-A1
Application number	US-201415107678-A
Country	US
Kind code	A1
Filing date	Aug 5, 2014
Priority date	Feb 27, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

A method is disclosed for the separation of ethane and heavier hydrocarbons or propane and heavier hydrocarbons from natural gas to provide a methane-rich natural gas stream and less volatile natural gas liquids (NGLs). This method provides for the use of a regenerable adsorbent media comprising a porous cross-linked polymeric adsorbent, a pyrolized macroporous polymer, or mixtures thereof, which is regenerated by a pressure swing adsorption (PSA) process, temperature swing adsorption (TSA) process, or combination of the two. Said regeneration step may be operated as a batch process, a semi-continuous process, or preferably as a continuous process.

First claim

What is claimed is:

1 . A process for separating natural gas liquids from a natural gas feedstream comprising methane and one or more of ethane, propane, butane, pentane, or heavier hydrocarbons, comprising the steps of:
(a) providing an adsorbent bed comprising an adsorbent media comprising a porous cross-linked polymeric adsorbent, a pyrolized macroporous polymer, or mixtures thereof, wherein said adsorbent media adsorbs ethane, propane, butane, pentane, heavier hydrocarbons, and/or mixtures thereof, (b) passing the natural gas feedstream through the adsorbent bed to provide a methane rich natural gas stream and a loaded adsorbent media, (c) recovering, transporting, liquefying, or flaring the methane rich natural gas stream, (d) regenerating the loaded adsorbent media to release the adsorbed ethane, propane, butane, pentane, heavier hydrocarbons, and/or mixtures thereof, (e) recovering, transporting, liquefying, re-injecting, excluding, by-passing, or flaring the ethane, propane, butane, heavier hydrocarbons, and/or pentane individually and/or as mixtures, and (f) reusing the regenerated adsorbent media,
wherein said passing of the natural gas stream through the adsorbent bed is performed in a pressure swing adsorption (PSA) vessel containing said adsorbent media, a temperature swing adsorption (TSA) vessel containing said adsorbent media, or a PSA vessel in combination with a TSA vessel.

2 . The process of claim 1 wherein the steps of the process are performed as a continually repeating cycle of steps in a system comprising a plurality of adsorption vessels which each undergo their respective cycle of steps while collectively operated sequentially in parallel with one another.

3 . The process of claim 1 wherein the adsorbent media is a partially pyrolyzed macroporous polymer comprising the product of controlled thermal degradation of a macroporous synthetic polymer containing macropores ranging from between 50 to 100,000 Angstroms in average critical dimension, a carbon-fixing moiety, and derived from one or more ethylenic ally unsaturated monomers, or monomers which may be condensed to yield macroporous polymers, or mixtures thereof, which partially pyrolyzed macroporous polymer comprises particles having: (a) at least 85% by weight of carbon, (b) multimodal pore distribution with macropores ranging in size from 50 Angstroms to 100,000 Angstroms in average critical dimension, and (c) a carbon to hydrogen atom ratio of between 1.5:1 and 20:1.

4 . The process of claim 3 wherein partially pyrolyzed macroporous polymer comprises particles wherein the surface area of the particles is measured by N 2 adsorption, as measured by the BET method, and ranges between 50 and 1500 m 2 /gram, of which the macropores contribute about 6 to about 700 m 2 /gram as determined by mercury intrusion techniques.

5 . The process of claim 1 wherein the adsorbent media is a cross-linked macroporous polymeric adsorbent which is a polymer of a monovinyl aromatic monomer crosslinked with a polyvinylidene aromatic compound.

6 . The process of claim 5 wherein the monovinyl aromatic monomer comprises from 92% to 99.25% by weight of said polymer, and said polyvinylidene aromatic compound comprises from 0.75% to 8% by weight of said polymer.

7 . The process of claim 5 wherein the cross-linked macroporous polymeric adsorbent is a polymer of a member selected from the group consisting of styrene, vinylbenzene, vinyltoluene, ethylstyrene, and t-butylstyrene; and is crosslinked with a member selected from the group consisting of divinylbenzene, trivinylbenzene, and ethylene glycol dimethacrylate.

8 . The process of claim 7 wherein the cross-linked macroporous polymeric adsorbent has a total porosity of from 0.5 to 1.5 cc/g, a surface area of from 150 to 2100 m 2 /g as measured by nitrogen adsorption, and an average pore diameter of from 10 Angstroms to 100 Angstroms.

Assignees

• Dow Global Technologies Llc

Inventors

• Matteucci Scott T
• Goltz H Robert
• Badhwar Ajay N
• Shurgott Nicholas J

Classifications

• B01J20/3441

  Regeneration or reactivation by electric current, ultrasound or irradiation, e.g. electromagnetic radiation such as X-rays, UV, light, microwaves · CPC title

• B01J20/3425

  of sorbents or filter aids comprising organic materials · CPC title

• B01J20/28066

  being more than 1000 m2/g · CPC title

• B01J20/20

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

• B01D53/047

  Pressure swing adsorption · CPC title