Closed-loop thermal servicing of solvent-refining columns

Patent metadata

Field	Value
Publication number	US-10293386-B2
Application number	US-201715819385-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	Sep 28, 2015
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A method of thermally servicing a solvent-refining column comprises: running a closed-loop water-steam system past a top and bottom of a first column, the first column containing at least a solvent and impurities; boiling pressurized water in the closed-loop water-steam system to steam using first heat from the top of the first column; compressing the steam in the closed-loop water-steam system to a higher temperature; and providing second heat to the first column by condensing the steam at the bottom of the first column after compression.

First claim

What is claimed is:

1. A method of thermally servicing a solvent-refining column, the method comprising:
running a closed-loop water-steam system past a top and a bottom of a first column, the first column containing at least a solvent and impurities;
boiling pressurized water in the closed-loop water-steam system to steam by transferring first heat from the top of the first column to the closed-loop water-steam system using a first heat exchanger;
compressing the steam in the closed-loop water-steam system to a higher temperature using a compressor; and
providing second heat to the first column by condensing the steam at the bottom of the first column after compression using a second heat exchanger.

2. The method of claim 1 , wherein water is separated from the solvent and the impurities in a second column, the method further comprising providing third heat to the second column by condensing the steam at a bottom of the second column after compression using a third heat exchanger.

3. The method of claim 2 , further comprising selectively bypassing, at least partially, the bottom of the first or second column with the closed-loop water-steam system using a bypass valve.

4. The method of claim 3 , further comprising applying a heater to the steam after the compression and before the bottom of the second column.

5. The method of claim 1 , further comprising selectively bypassing, at least partially, the bottom of the first column with the closed-loop water-steam system using a bypass valve.

6. The method of claim 1 , further comprising applying a heater to the steam after compression and before the bottom of the first column.

7. The method of claim 1 , wherein the impurities have a boiling point that is less than about 2% lower or higher than a boiling point of the solvent.

8. The method of claim 7 , wherein the solvent is n-methyl pyrrolidone and wherein the impurities are partial oxides of the n-methyl pyrrolidone.

9. The method of claim 1 , further comprising selectively bypassing, at least partially, the top of the first column with the closed-loop water-steam system using a bypass valve.

10. The method of claim 1 , further comprising throttling condensed water in the closed-loop water-steam system, using an expansion valve, before boiling the pressurized water.

Assignees

• Tesla Inc

Inventors

• Melsert Ryan

Classifications

• B01D1/0047

  in a closed circuit (B01D3/007 takes precedence) · CPC title

• B01D3/00

  Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping ({evaporation in general, e.g. of liquids for gas phase reactions B01B1/005;} gas chromatography B01D15/08; destructive distillation C10B; preparation of alcoholic beverages by distillation C12H6/02) · CPC title

• B08B9/08 Primary

  Cleaning containers, e.g. tanks · CPC title

• B01D5/0039

  Recuperation of heat, e.g. use of heat pump(s), compression · CPC title

• B01D3/007

  Energy recuperation; Heat pumps · CPC title