# US 11,298,668 B2 · Process to produce nanoparticles

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- Number: US 11,298,668 B2
- Document ID: US11298668B2
- Status: Granted
- Kind: B2
- Application number: 16/762,168
- Filed: 2018-11-08
- Published: 2020-11-12
- Granted: 2022-04-12
- Earliest claimed: 2017-11-09
- Assignees: BLH Ecology Concepts, L.L.C.
- Applicants: Blh Ecology Concepts, LLC
- Inventors: Richard Francis Reidy; John E. Lott; Gerhardt E. Wissler; Mark C. Hill
- Web page: https://patentgrep.com/patent/US11298668B2

## CPC

- B01J 3/008: {Processes carried out under supercritical conditions}
- B01J 2/02: by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops
- B01J 2/26: on endless conveyor belts
- B01J 19/22: in the form of endless belts
- B01J 19/28: Moving reactors, e.g. rotary drums (B01J19/08 takes precedence)
- C01B 32/55: Solidifying
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}

## Abstract

A process for producing nanoparticles of a substance, including in a first chamber, forming a dispersion of a substance in a fluid and bringing the fluid into a supercritical state; passing the dispersion from the first chamber through a cooling device or into a cooling zone in a second chamber, wherein the cooling device or cooling zone configured to reduce temperature of the dispersion below a temperature at which the fluid forms solid particles such that nanoparticles of the substance are formed, wherein the second chamber comprises a surface configured to receive the solid particles of the fluid and the nanoparticles of the substance; allowing pressure to decrease and/or temperature to increase in the second chamber to transform the solid particles into a gaseous state, removing the fluid in the gaseous state and with the nanoparticles remaining on the surface; and collecting the nanoparticles from the surface.

## Claims

### Claim 1

A process for producing nanoparticles of a substance, comprising:
in a first chamber, dispersing a substance in a fluid and bringing the fluid into a supercritical state at a selected pressure and temperature to form a dispersion of the substance and the fluid in the supercritical state;
passing the dispersion from the first chamber either through a cooling device into a second chamber or into a cooling zone in the second chamber, wherein the cooling device or cooling zone reduces the temperature of the passing dispersion below a temperature at which the fluid forms solid particles such that both solid particles of the fluid and nanoparticles of the substance are formed, wherein the second chamber further comprises a surface configured to receive the solid particles of the fluid and the nanoparticles of the substance, and both the solid particles of the fluid and the nanoparticles of the substance are deposited upon the surface together;
wherein the surface configured to receive solid particles of the fluid and nanoparticles of the substance is further configured to transport the nanoparticles to a nanoparticle collection zone;
moving the surface towards the nanoparticle collection zone, wherein, as the surface moves towards the nanoparticle collection zone, allowing at least one of pressure to decrease and temperature to increase such that the solid particles of the fluid deposited on the surface are transformed into a gaseous state, and removing the fluid in the gaseous state while the nanoparticles of the substance remain on the surface; and
collecting the nanoparticles of the substance from the surface in the nanoparticle collection zone.

### Claim 2 (depends on 1)

The process of claim 1 wherein the dispersing further comprises adding a co-solvent to enhance solubility of the substance in the fluid.

### Claim 3 (depends on 2)

The process of claim 2 wherein in the passing, the temperature of the dispersion is reduced below the temperature at which the co-solvent forms a solid.

### Claim 4 (depends on 3)

The process of claim 3 wherein in the allowing, the co-solvent evaporates and is removed with the fluid in the gaseous state.

### Claim 5 (depends on 1)

The process of claim 1 wherein the surface is disposed upon an endless conveyor or a rotatable drum.

### Claim 6 (depends on 1)

The process of claim 1 wherein the collecting comprises scraping the nanoparticles from the surface or lifting the nanoparticles from the surface by suction or electrostatic attraction.

### Claim 7 (depends on 1)

The process of claim 1 wherein the process is operated on a continuous basis.

### Claim 8 (depends on 1)

The process of claim 1 in which the fluid is carbon dioxide.

### Claim 9 (depends on 1)

The process of claim 1 wherein the process is free of any step of filtration to collect the nanoparticles.

### Claim 10 (depends on 1)

The process of claim 1 wherein the process is free of any added surface modifier in any step of the process.

### Claim 11 (depends on 1)

The process of claim 1 wherein the process is free of any added antisolvent in any step of the process.

### Claim 12 (depends on 1)

The process of claim 1 wherein the nanoparticles of the substance have an average size in the range from about 1 nm to about 1000 nm.

### Claim 13 (depends on 1)

The process of claim 1 wherein the nanoparticles of the substance have an average size in the range from about 50 nm to about 500 nm.

### Claim 14 (depends on 1)

The process of claim 1 wherein the nanoparticles of the substance have an average size in the range from about 200 nm to about 300 nm.