# US 11,440,866 B2 · Systems and methods for purifying solvents

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,440,866 B2
- Document ID: US11440866B2
- Status: Granted
- Kind: B2
- Application number: 17/342,581
- Filed: 2021-06-09
- Published: 2021-12-16
- Granted: 2022-09-13
- Earliest claimed: 2020-06-12
- Assignees: Fujifilm Electronic Materials U.S.A., Inc.
- Applicants: Fujifilm Electronic Materials U.S.A., Inc.
- Inventors: Yuan Chen; Eduardo Ramirez Romero; Bryan Hinzie
- Web page: https://patentgrep.com/patent/US11440866B2

## CPC

- C07C 45/783: {by gas-liquid treatment, e.g. by gas-liquid absorption}
- B01D 3/143: {by two or more of a fractionation, separation or rectification step}
- B01D 36/00: Filter circuits or combinations of filters with other separating devices
- B01D 39/16: of organic material, e.g. synthetic fibres
- B01D 39/1623: {of synthetic origin}
- B01D 39/1653: {of synthetic origin}
- B01J 20/261: {obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F)}
- C07C 45/786: {by membrane separation process, e.g. pervaporation, perstraction, reverse osmosis}
- C07C 45/82: by distillation
- C11D 7/5022: {containing oxygen}
- B01D 2239/1216: Pore size
- C07C 2601/14: The ring being saturated
- C11D 2111/22: Electronic devices, e.g. PCBs or semiconductors
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL

## Abstract

The present disclosure is directed to methods and systems of purifying solvents. The purified solvents can be used, e.g., as pre-wet liquids, solution developers, and cleaners in a multistep semiconductor manufacturing process.

## Claims

### Claim 1

A method for purifying an organic solvent, comprising:
distilling the organic solvent in a first distillation column to obtain an intermediate organic solvent, wherein the first distillation column has an inlet positioned at a location that is from about 80% to about 100% of the height of the first distillation column;
transferring the intermediate organic solvent to a second distillation column, wherein the second distillation column has an inlet positioned at a location that is from about 0% to about 30% of the height of the second distillation column; and
distilling the intermediate organic solvent in the second distillation column to obtain a distilled organic solvent.

### Claim 2 (depends on 1)

The method of claim 1, wherein distilling the organic solvent in the first distillation column removes impurities having a boiling point lower than the boiling point of the organic solvent.

### Claim 3 (depends on 1)

The method of claim 1, wherein distilling the intermediate organic solvent in the second distillation column removes impurities having a boiling point higher than the boiling point of the organic solvent.

### Claim 4 (depends on 1)

The method of claim 1, further comprising preheating the organic solvent to a temperature at least about 20° C. below the boiling point of the organic solvent before distilling the organic solvent in the first distillation column, wherein the preheating is performed by a preheater upstream of and in fluid communication with the first distillation column.

### Claim 5 (depends on 1)

The method of claim 1, further comprising passing the organic solvent through a first filter unit upstream of the first distillation column, wherein the first filter unit comprises a first housing and at least one first filter in the first housing, and the at least one first filter comprises a filtration medium.

### Claim 6 (depends on 5)

The method of claim 5, wherein the filtration medium in the at least one first filter comprises a polyolefin, a polyamide, a fluoropolymer, or a copolymer thereof.

### Claim 7 (depends on 6)

The method of claim 6, wherein the filtration medium in the at least one first filter comprises polypropylene or polytetrafluoroethylene.

### Claim 8 (depends on 5)

The method of claim 5, wherein the filtration medium in the at least one first filter has an average pore size from about 50 nm to about 250 nm.

### Claim 9 (depends on 5)

The method of claim 5, wherein the at least one first filter is a particle removal filter.

### Claim 10 (depends on 1)

The method of claim 1, further comprising passing the distilled organic solvent through a second filter unit downstream of the second distillation column, wherein the second filter unit comprises a second housing and at least one second filter in the second housing, and the at least one second filter comprises a filtration medium.

### Claim 11 (depends on 10)

The method of claim 10, wherein the filtration medium in the at least one second filter comprises a polyolefin, a polyamide, a fluoropolymer, or a copolymer thereof.

### Claim 12 (depends on 11)

The method of claim 11, wherein the filtration medium in the at least one second filter comprises nylon or polytetrafluoroethylene.

### Claim 13 (depends on 10)

The method of claim 10, wherein the filtration medium in the at least one second filter has an average pore size from about 2 nm to 10 nm.

### Claim 14 (depends on 10)

The method of claim 10, wherein the at least one second filter is a particle removal filter.

### Claim 15 (depends on 10)

The method of claim 10, further comprising recirculating the organic solvent exiting the second filter unit.

### Claim 16 (depends on 15)

The method of claim 15, wherein the recirculating comprises moving the organic solvent exiting the second filter unit to a distilled solvent tank and subsequently passing the organic solvent through the second filter unit, and the distilled solvent tank is between and in fluid communication with the second distillation column and the second filter unit.

### Claim 17 (depends on 1)

The method of claim 1, further comprising moving the distilled organic solvent to a product container downstream of and in fluid communication with the second distillation column.

### Claim 18 (depends on 1)

The method of claim 1, wherein the organic solvent comprises cyclohexanone, ethyl lactate, n-butyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 4-methyl-2-pentanol, or propylene carbonate.

### Claim 19

A system, comprising:
a first distillation column having a first inlet and a first outlet, wherein the first inlet is positioned at a location that is from about 80% to about 100% of the height of the first distillation column; and
a second distillation column downstream of the first distillation column and having a second inlet and a second outlet, wherein the second inlet is in fluid communication with the first outlet, and the second inlet is positioned at a location that is from about 0% to about 30% of the height of the second distillation column.

### Claim 20 (depends on 19)

The system of claim 19, further comprising a preheater, wherein the preheater is upstream of and in fluid communication with the first distillation column.

### Claim 21 (depends on 20)

The system of claim 20, further comprising a first filter unit upstream of and in fluid communication with the preheater, wherein the first filter unit comprises a first housing and at least one first filter in the first housing, and the at least one first filter comprises a filtration medium.

### Claim 22 (depends on 21)

The system of claim 21, wherein the filtration medium in the at least one first filter comprises a polyolefin, a polyamide, a fluoropolymer, or a copolymer thereof.

### Claim 23 (depends on 22)

The system of claim 22, wherein the filtration medium in the at least one first filter comprises polypropylene or polytetrafluoroethylene.

### Claim 24 (depends on 21)

The system of claim 21, wherein the filtration medium in the at least one first filter has an average pore size from about 50 nm to about 250 nm.

### Claim 25 (depends on 21)

The system of claim 21, wherein the at least one first filter is a particle removal filter.

### Claim 26 (depends on 19)

The system of claim 19, further comprising a second filter unit downstream of the second distillation column, wherein the second filter unit comprises a second housing and at least one second filter in the second housing, and the at least one second filter comprises a filtration medium.

### Claim 27 (depends on 26)

The system of claim 26, wherein the filtration medium in the at least one second filter comprises a polyolefin, a polyamide, a fluoropolymer, or a copolymer thereof.

### Claim 28 (depends on 27)

The system of claim 27, wherein the filtration medium in the at least one second filter comprises nylon or polytetrafluoroethylene.

### Claim 29 (depends on 26)

The system of claim 26, wherein the filtration medium in the at least one second filter has an average pore size from about 2 nm to 10 nm.

### Claim 30 (depends on 26)

The system of claim 26, wherein the at least one second filter is a particle removal filter.

### Claim 31 (depends on 19)

The system of claim 19, further comprising a distilled solvent tank between and in fluid communication with the second distillation column and the second filter unit.

### Claim 32 (depends on 31)

The system of claim 31, further comprising a recirculation loop, wherein the recirculation loop comprises the second filter unit and the distilled solvent tank.

### Claim 33 (depends on 19)

The system of claim 19, further comprising a product container downstream of and in fluid communication with the second distillation column.