Solvent recycle from heavies removal column

Patent metadata

Field	Value
Publication number	US-10584081-B2
Application number	US-201715588906-A
Country	US
Kind code	B2
Filing date	May 8, 2017
Priority date	May 25, 2016
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A process is presented for the recovery of solvent used in an alkylation process. The solvent removes heavy hydrocarbons from a C4 stream. The C4 stream is passed to an alkylation unit to generate an alkylate product. A portion of the solvent is carried over with the C4 stream and needs to be recovered to reduce the aromatics content in the C4 stream, to reduce any deleterious effects of the aromatics in downstream processing.

First claim

The invention claimed is:

1. A process for recovery of solvent, comprising:
passing a hydrocarbon stream to a dehydrogenation unit to generate a first process stream comprising olefins;
contacting the first process stream with a solvent stream in a contact cooler to generate an olefins stream, and a second process stream comprising solvent;
passing the olefins stream to a cold box separation unit to separate a light gases stream from a condensed stream, wherein the light gases stream from the cold box separation unit comprises hydrogen, C1 to C3 hydrocarbons, non-condensable gases, or any combination thereof;
passing the condensed stream to a selective hydrogenation unit to generate a condensed stream having reduced acetylenes;
passing the condensed stream having reduced acetylenes to a deethanizer or a depropanizer to generate an overhead stream and a C4 bottoms stream;
passing the C4 bottoms stream to a heavies removal column to generate a heavies overhead stream comprising olefins, and a heavies bottoms stream comprising C5 + hydrocarbons and solvent; and
passing a portion of the heavies bottoms stream to the contact cooler.

2. The process of claim 1 wherein the portion of the heavies bottoms stream passed to the contact cooler is between 5 wt.-% and 95 wt.-% of the heavies bottoms stream.

3. The process of claim 2 wherein the portion of the heavies bottoms stream passed to the contact cooler is between 25 wt.-% and 90 wt.-% of the heavies bottoms stream.

4. The process of claim 1 wherein the hydrocarbon stream comprises normal butane or isobutane or a mixture of normal butane and isobutane.

5. The process of claim 1 wherein the olefins stream is compressed to generate a compressed stream.

6. The process of claim 5 wherein the compressed stream is treated in a chloride treater unit to generate a treated stream.

7. The process of claim 6 wherein the treated stream is passed to the cold box separation unit.

Assignees

• Uop Llc

Inventors

• Zavala Raul
• Luebke Charles P
• Kanyuh Adam J

Classifications

• C07C7/148

  by treatment giving rise to a chemical modification of at least one compound · CPC title

• C10G2400/20

  C2-C4 olefins · CPC title

• C07C7/04

  by distillation · CPC title

• C07C7/11

  by absorption, i.e. purification or separation of gaseous hydrocarbons with the aid of liquids · CPC title

• C10G9/00

  Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils · CPC title