# US 2019/0169026 A1 · Apparatus and method for separating liquid oxygen from liquified air

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- Number: US 2019/0169026 A1
- Document ID: US20190169026A1
- Status: Published application
- Kind: A1
- Application number: 16/313,336
- Filed: 2017-06-27
- Published: 2019-06-06
- Earliest claimed: 2016-06-27
- Assignees: Texas Tech University System
- Applicants: Texas Tech University System
- Inventors: Robert V. Duncan
- Web page: https://patentgrep.com/patent/US20190169026A1

## CPC

- C01B 13/0248: {Physical processing only}
- B01D 17/0214: {with removal of one of the phases}
- B01D 19/00: Degasification of liquids
- F17C 5/02: for filling with liquefied gases
- F25J 3/04636: {using a hybrid air separation unit, e.g. combined process by cryogenic separation and non-cryogenic separation techniques (F25J3/04733 and F25J3/04757 take precedence)}
- F25J 2205/86: using electrical phenomena, e.g. Corona discharge, electrolysis or magnetic field
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- 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)
- F17C: VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES (storing fluids in natural or artificial cavities or chambers in the earth B65G5/00; construction or assembling of bulk storage containers employing civil-engineering techniques E04H7/00; variable-capacity gas-holders F17B; liquefaction or refrigeration machines, plants, or systems F25)
- F25J: LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS {OR LIQUEFIED GASEOUS} MIXTURES BY PRESSURE AND COLD TREATMENT {OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE (cryogenic pumps F04B37/08; gas storage vessels, gas holders F17; filing vessels with, or discharging from vessels, compressed, liquefied or solidified gases F17C; refrigeration machines, plants, or systems F25B)}

## Abstract

An apparatus and method of separation of LOX and other commercially valuable components, such as LAr from liquefied air, which consists primarily of LN2. Strong magnetic field gradient and gravity are used to separate LOX from liquefied air, based upon the different magnetic properties of LOX and LN2. The apparatus and method employ a magnetic field gradient to levitate the LN2 and LAr diamagnetic components of liquid air while accelerating the paramagnetic LOX component toward the bottom to achieve oxygen separation. In other embodiments, a leak valve system can be used.

## Claims

### Claim 1

An apparatus for separating liquid oxygen from liquid air comprising
(a) a liquid air storage container;
(b) a separation system that is selected from a group consisting of (i) a magnetic field system, (ii) leak valve system, and (iii) a combination thereof, wherein
(i) the separation system is operatively connected to the liquid air storage container, and
(ii) the separation system is operable to separate liquid oxygen from liquid air from the storage container; and
(c) a second container, wherein the second container is
(i) operatively connected to the separation system, and
(ii) operative to collect liquid oxygen separated from the liquid air by the separation system.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein
(a) the liquid air storage container contains liquid air, wherein the liquid air storage container comprises
(i) a bottom section that has a portion of the liquid air that is rich in liquid oxygen due to gravity, and
(ii) a top section that has air vapor;
(b) the apparatus further comprises a first conduit, wherein the first conduit is operatively connected to (i) the bottom section of the liquid air storage container and (ii) the separation system, to provide for the liquid air that is rich in liquid oxygen to flow from the liquid air storage container, through the first conduit, and to the separation system;
(c) the apparatus further comprises a second conduit, wherein
(i) the second conduit is operatively connected to (A) the separation system and (B) the second container, to provide for the liquid oxygen separated by the separation system to flow from the separation system, through the conduit, and to the second container, and
(ii) the second storage container contains liquid oxygen.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the liquid oxygen is collected in the second storage container via gravity.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the separation system comprises the magnetic field system.

### Claim 5 (depends on 4)

The apparatus of claim 4, wherein the magnetic field system is operable to levitate liquid oxygen from the liquid air based upon the different magnetic properties of liquid oxygen and liquid nitrogen.

### Claim 6 (depends on 5)

The method of claim 5, wherein in the magnetic field has a field and gradient that is between about 105% and about 140% of the requirement to levitate liquid oxygen.

### Claim 7 (depends on 4)

The apparatus of claim 4, wherein the magnetic field system comprises an acceleration magnet.

### Claim 8 (depends on 7)

The apparatus of claim 7, wherein the acceleration magnet comprises a gradient coil.

### Claim at position 9

9-10. (canceled)

### Claim 11 (depends on 8)

The apparatus of claim 8, wherein the gradient coil is wound to achieve a field and gradient that is between about 105% and about 140% of the requirement to levitate liquid oxygen.

### Claim 12 (depends on 8)

The apparatus of claim 8, wherein the gradient coil is wound to achieve a field and gradient that is between about 8.5 T2/m and about 11.5 T2/m.

### Claim 13

(canceled)

### Claim 14 (depends on 1)

The apparatus of claim 1, wherein the separation system comprises the leak valve system.

### Claim 15 (depends on 14)

The apparatus of claim 14, wherein the leak valve system comprises one or more adjustable controllers and sensors that are operable to separate liquid oxygen from the liquid air.

### Claim 16 (depends on 1)

The apparatus of claim 1, wherein the apparatus is capable of collecting ultra-pure liquid oxygen in the second container.

### Claim 17 (depends on 16)

The apparatus of claim 16, wherein the ultra-pure liquid oxygen is at least about 98% liquid oxygen by weight.

### Claim 18 (depends on 16)

The apparatus of claim 16, wherein the ultra-pure liquid oxygen is at least about 99.5% liquid oxygen by weight.

### Claim 19 (depends on 16)

The apparatus of claim 16, wherein the ultra-pure liquid oxygen is at least about 98% liquid oxygen by mole.

### Claim 20

A method of separating liquid oxygen from liquid air comprising the steps of:
(a) storing liquid air in a liquid air storage container, wherein the liquid storage container comprises
(i) a bottom section that has a portion of the liquid air that is rich in liquid oxygen due to gravity, and
(ii) a top portion that has air vapor;
(b) flowing liquid air from the bottom section to a separation system, wherein the separation system is selected from a group consisting of (i) a magnetic field system, (ii) leak valve system, and (iii) a combination thereof;
(c) utilizing the separation system to separate liquid oxygen from the liquid air that is rich in liquid oxygen; and
(d) collecting the liquid oxygen in a second storage container.

### Claim 21 (depends on 20)

The method of claim 20, wherein the liquid oxygen is collected in the second storage container via gravity.

### Claim 22 (depends on 20)

The method of claim 20, wherein the separation system comprises the magnetic field.

### Claim 23 (depends on 22)

The method of claim 22, wherein the step of utilizing the separation system comprises utilizing the magnetic field to levitate liquid oxygen from the liquid air based upon the different magnetic properties of liquid oxygen and liquid nitrogen.

### Claim 24 (depends on 22)

The method of claim 22, wherein the step of utilizing the separation system comprises utilizing an acceleration magnet.

### Claim 25 (depends on 24)

The method of claim 24, wherein the acceleration magnet comprises a gradient coil.

### Claim at position 25

26-27. (canceled)

### Claim 28 (depends on 25)

The method of claim 25, wherein the gradient coil is wound to achieve a field and gradient that is between about 105% and about 140% of the requirement to levitate liquid oxygen.

### Claim 29 (depends on 25)

The method of claim 25, wherein the gradient coil is wound to achieve a field and gradient that is between about 8.5 T2/m and about 11.5 T2/m.

### Claim 30

(canceled)

### Claim 31 (depends on 20)

The method of claim 20, wherein the separation system comprises the leak valve system.

### Claim 32 (depends on 31)

The method of claim 31, wherein the step of utilizing the separation system comprises utilizing the leak valve system using one or more adjustable controllers and sensors to separate liquid oxygen from the liquid air.

### Claim 33 (depends on 20)

The method of claim 20, wherein the step of collecting liquid oxygen in the second storage container comprises collecting ultra-pure liquid oxygen in the second container.

### Claim 34 (depends on 33)

The method of claim 33, wherein the ultra-pure liquid oxygen is at least about 98% liquid oxygen by weight.

### Claim 35 (depends on 33)

The method of claim 33, wherein the ultra-pure liquid oxygen is at least about 99.5% liquid oxygen by weight.

### Claim 36 (depends on 33)

The method of claim 33, wherein the ultra-pure liquid oxygen is at least about 98% liquid oxygen by mole.

### Claim at position 35

37-49. (canceled)