# US 2024/0216889 A1 · Storage medium for storing hydrogen chloride and method for separating and storing hydrogen chloride hcl from hcl containing gas

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- Number: US 2024/0216889 A1
- Document ID: US20240216889A1
- Status: Published application
- Kind: A1
- Application number: 18/684,109
- Filed: 2022-08-11
- Published: 2024-07-04
- Earliest claimed: 2021-08-19
- Assignees: Freie UniversitäT Berlin
- Applicants: Freie UniversitäT Berlin
- Inventors: Sebastian HASENSTAB-RIEDEL; Patrick VOßNACKER
- Web page: https://patentgrep.com/patent/US20240216889A1

## CPC

- B01J 20/22: comprising organic material
- C01B 7/0743: {of gaseous or dissolved chlorine}
- B01D 53/1493: {Selection of liquid materials for use as absorbents}
- B01J 20/28011: {Other properties, e.g. density, crush strength}
- C01B 7/0718: {by adsorption}
- C25B 1/02: Hydrogen or oxygen
- C25B 1/26: Chlorine; Compounds thereof (by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34)
- B01D 2252/30: Ionic liquids and zwitter-ions
- B01D 2257/2045: Hydrochloric acid
- Y02E 60/32: Hydrogen storage
- 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}
- 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)
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

It is provided a storage medium for storing hydrogen chloride (HCl) comprising at least one ionic compound of the general formulae (I) Wherein R1, R2, R3 being independent from each other an alkyl moiety selected from the group of methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and sec-butyl, preferably methyl, ethyl, n-propyl; Wherein at least one of the moieties R1, R2, R3 differs from each of the others moieties R1, R2, R3; Wherein a, b, c are independently from each other 0, 1, 2 or 3, wherein the sum of a+b+c always has to be 4; Wherein n>=1, preferably n=1-6, more preferably n=1, 2, 3, 4, with a viscosity in a range between 5 and 50 mPas, preferably between 10 and 20 mPas (25° C., 1000 hPa).

## Claims

### Claim 1

A storage medium for storing hydrogen chloride (HCl) comprising at least one ionic compound of the general formulae (I)
Wherein R1, R2, R3 being independent from each other an alkyl moiety selected from the group of methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and sec-butyl, preferably methyl, ethyl, n-propyl, n-butyl;
Wherein at least one of the moieties R1, R2, R3 differs from each of the others moieties R1, R2, R3;
Wherein a, b, c are independently from each other 0, 1, 2 or 3, wherein the sum of a+b+c always has to be 4;
Wherein n>=1, preferably n=1-6, more preferably n=1, 2, 3, 4, and
With a viscosity in a range between 5 and 50 mPas, preferably between 10 and 20 mPas (25° C., 1000 hPa).

### Claim 2 (depends on 1)

The storage medium according to claim 1, wherein in the ionic compound of general formula (I) a, b=1, 2 or 3, and c=0, 1.

### Claim 3 (depends on 1)

The storage medium according to claim 1, wherein the ionic compound of general formula (I) is selected from [NEt3Me][Cl(HCl)n], [NEt2Me2][Cl(HCl)n], [NEtMe3][Cl(HCl)n], [NBuEt2Me][Cl(HCl)n], [NPr3Me][Cl(HCl)n], [NBu2Me2][Cl(HCl)n], with n being 1-6, preferably 1-4.

### Claim 4 (depends on 1)

The storage medium according to claim 1, wherein the ionic compound of general formula (I) is selected from [NEt3Me][Cl(HCl)n], [NEt2Me2][Cl(HCl)n], [NEtMe3][Cl(HCl)n], with n being 1-6, preferably 1-4.

### Claim 5 (depends on 1)

The storage medium according to claim 1, wherein the ionic compound of general formula (I) contains (in the loaded state) at least 0.3 g HCl/g ionic compound, preferably at least 0.4 g HCl/g ionic compound, more preferably at least 0.5 g HCl/g ionic compound.

### Claim 6 (depends on 1)

The storage medium according to claim 1, having a conductivity of at least 20 mS/cm (20° C.), preferably at least 30 mS/cm, more preferably at least 40 mS/cm, even more preferably at least 50 mS/cm.

### Claim 7 (depends on 1)

The storage medium according to claim 1, having a hydrogen H2 development at at least 1 V, preferably at least 0.8 V, more preferably at least 0.5 V, such as in the range of 1-1.5 V, preferably in the range of 1-1.2 V.

### Claim 8

(canceled)

### Claim 9

A method for separating and storing hydrogen chloride HCl from HCl containing gas, in particular HCl containing process gas, by contacting the HCl containing gas with at least one ionic compound of general formulae (II)
Wherein R1, R2, R3 being independent from each other an alkyl moiety selected from the group of methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and sec-butyl, preferably methyl, ethyl, n-propyl,
Wherein at least one of the moieties R1, R2, R3 differs from each of the others moieties R1, R2, R3,
Wherein a, b, c are independently from each other 0, 1, 2 or 3, wherein the sum of a+b+c always has to be 4;
Wherein the hydrogen chloride HCl from the HCl containing gas is bound by the at least one ionic compound of general formulae (II) thereby providing the ionic compound of general formulae (I)
Wherein R1, R2, R3 being independent from each other an alkyl moiety selected from the group of methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and sec-butyl, preferably methyl, ethyl, n-propyl;
Wherein at least one of the moieties R1, R2, R3 differs from each of the others moieties R1, R2, R3;
Wherein a, b, c are independently from each other 0, 1, 2 or 3, wherein the sum of a+b+c always has to be 4;
Wherein n>=1, preferably n=1-6, more preferably n=1, 2, 3, 4.

### Claim 10 (depends on 9)

The method according to claim 9, wherein the ionic compound of general formula (II) is selected from [NEt3Me][Cl], [NEt2Me2][Cl], [NEtMe3][Cl], [NBuEt2Me][Cl], [NPr3Me][Cl], [NBu2Me2][Cl], preferably from [NEt3Me][Cl], [NEt2Me2][Cl], [NEtMe3][Cl].

### Claim 11 (depends on 1)

A method for releasing hydrogen and chlorine from an ionic compound of general formulae (I) according to claim 1, wherein the hydrogen chloride HCl stored in the ionic compound of general formulae (I) is split into hydrogen H2 and intermediate chlorine Cl2 by electrolysis and the compound of general formulae (II) is obtained.

### Claim 12 (depends on 11)

The method according to claim 11, wherein the intermediate chlorine Cl2 obtained during electrolysis is stored in the ionic compound of general formulae (II) providing an ionic compound of general formulae (III)
Wherein R1, R2, R3 being independent from each other an alkyl moiety selected from the group of methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl and sec-butyl, preferably methyl, ethyl, n-propyl;
Wherein at least one of the moieties R1, R2, R3 differs from each of the others moieties R1, R2, R3,
Wherein a, b, c are independently from each other 0, 1, 2 or 3, wherein the sum of a+b+c always has to be 4;
Wherein n>=1, preferably n=1-7, more preferably n=3, 5, 7.