# US 10,864,511 B2 · Methods of producing ferrihydrite nanoparticle slurries, and systems and products employing the same

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- Number: US 10,864,511 B2
- Document ID: US10864511B2
- Status: Granted
- Kind: B2
- Application number: 16/558,280
- Filed: 2019-09-02
- Published: 2020-02-27
- Granted: 2020-12-15
- Earliest claimed: 2016-03-28
- Applicants: SulfurCycle Intellectual Property Holding Company, LCC
- Inventors: Charles Deane Little; Megan Catherine Cousins; Margarite Patricia Parker; Tara S. Gedvilas; Jason Aaron Barton; Philip Henry Michael; Joe Kosmoski
- Web page: https://patentgrep.com/patent/US10864511B2

## CPC

- B01J 47/018: Granulation; Incorporation of ion-exchangers in a matrix; Mixing with inert materials
- B01J 20/0229: {Compounds of Fe}
- 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)}
- B01J 20/28007: {with size in the range 1-100 nanometers, e.g. nanosized particles, nanofibers, nanotubes, nanowires or the like (carbon nanostructures B01J20/205)}
- B01J 20/3085: {Chemical treatments not covered by groups B01J20/3007 - B01J20/3078}
- B01J 20/3204: {Inorganic carriers, supports or substrates}
- B01J 20/327: {Polymers obtained by reactions involving only carbon to carbon unsaturated bonds}
- B01J 20/3433: {of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425}
- B01J 20/3458: {in the gas phase}
- C02F 2103/06: Contaminated groundwater or leachate
- Y02C 20/40: of CO2
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]

## Abstract

The present disclosure relates to methods of synthesizing slurries comprising ferrihydrite nanoparticles, and systems and methods employing the same. The method may include the steps of preparing an aqueous solution having ferric iron cations, halide anions, and a two-line iron promoter, and precipitating the ferrihydrite nanoparticles in the aqueous solution, thereby producing a ferrihydrite slurry. The ferrihydrite slurries may be useful in treating a polluted fluid having sulfur contaminants therein.

## Claims

### Claim 1

A method for treating a H2S-containing fluid stream, the method comprising:
(a) contacting a H2S -containing fluid stream with a ferrihydrite slurry, wherein the ferrihydrite slurry includes ferrihydrite nanoparticles and a 2LI promotor wherein the contacting step results in
(i) a treated fluid stream comprising less H2S than the H2S -containing stream and
(ii) a used slurry including ferrous sulfide, a 2LI promotor, and a first sulfur concentration of sulfur obtained from the H2S -containing stream;
(b) regenerating the used slurry to obtain elemental sulfur and a regenerated ferrihydrite slurry, wherein regenerating includes:
(i) contacting the used slurry with an oxidizing agent thereby converting at least some of the sulfur in the used slurry into elemental sulfur and converting at least some of the ferrous sulfide in the used slurry into regenerated ferrihydrite thereby forming regenerated ferrihydrite slurry; and
(ii) separating the elemental sulfur from the regenerated ferrihydrite slurry, wherein the regenerated ferrihydrite slurry includes ferrihydrite nanoparticles and a 2LI promotor and a second sulfur concentration less than the first sulfur concentration of the used slurry;
wherein the 2LI promotor is selected from the group consisting of D-sorbitol, alkali metasilicates and combinations thereof.

### Claim 2 (depends on 1)

The method of claim 1, wherein steps (a) through (b) are repeated with the regenerated ferrihydrite slurry.

### Claim 3 (depends on 2)

The method of claim 2, wherein the 2LI promotor is selected from the group consisting of D-sorbitol, sodium metasilicates, and combinations thereof.

### Claim 4 (depends on 2)

The method of claim 2, wherein the H2S -containig fluid stream is natural gas.

### Claim 5 (depends on 2)

The method of claim 2, wherein the H2S -containing fluid stream is off-gas.

### Claim 6 (depends on 2)

The method of claim 2, wherein the H2S -containig fluid stream is sour crude oil.

### Claim 7 (depends on 2)

The method of claim 2, wherein the H2S -containig fluid stream is sour water.

### Claim 8 (depends on 2)

The method of claim 2, wherein the H2S concentration of the treated fluid stream is 4 ppm or less.

### Claim 9 (depends on 2)

The method of claim 2, wherein the oxidizing agent is oxygen from air.

### Claim 10 (depends on 2)

The method of claim 2, wherein the regenerated ferrihydrite slurry realizes a six-cycle activity of at least 6.0, and at least three of the cycles realize a slurry activity of at least 1.0.

### Claim 11 (depends on 2)

The method of claim 2 wherein the regenerated ferrihydrite slurry realizes a six-cycle loss of not greater than 45%.

### Claim 12 (depends on 2)

The method of claim 2 wherein the regenerated ferrihydrite slurry realizes a six-cycle capture efficiency average of at least 92% and a six-cycle standard deviation of not greater than 1.75%.

### Claim 13 (depends on 2)

The method of claim 2 wherein elemental sulfur is separated from the used slurry in a regenerator.

### Claim 14 (depends on 13)

The method of claim 13 wherein an output of the regenerator is regenerated ferrihydrite slurry that is used in a subsequent contacting operation.

### Claim 15 (depends on 2)

The method of claim 2, wherein the oxidizing agent is air.

### Claim 16 (depends on 2)

The method of claim 2, wherein the H2S -containig fluid stream is a gas containing CO2.

### Claim 17 (depends on 2)

The method of claim 2, wherein the contacting further comprises:
flowing the H2S -containing fluid stream into a contactor containing the ferrihydrite slurry; and
removing the treated fluid stream comprising less H2S than the H2S -containing stream from the contactor.

### Claim 18 (depends on 2)

The method of claim 2, wherein regenerating further comprises:
transferring used slurry from a contactor that performs the contacting operation a) to a regenerator that performs the regeneration operation b); and
transferring regenerated ferrihydrite slurry from the regenerator to the contactor.

### Claim 19 (depends on 2)

The method of claim 2, further comprising:
flowing the H2S-containing fluid stream into a contacting column containing the ferrihydrite slurry;
removing the treated fluid stream comprising less H2S than the H2S -containing stream from the contacting column;
transferring used slurry from a contactor that performs the contacting operation a) to a regenerator that performs the regeneration operation b); and
transferring regenerated ferrihydrite slurry from the regenerator to the contactor.

### Claim 20 (depends on 19)

The method of claim 19 wherein the contactor is a first column and the regenerator is a second column.