Storage medium and method for separating, storing and transporting chlorine from chlorine-containing gases

Patent metadata

Field	Value
Publication number	US-2021087057-A1
Application number	US-201917054149-A
Country	US
Kind code	A1
Filing date	May 3, 2019
Priority date	May 7, 2018
Publication date	Mar 25, 2021
Grant date	—

Abstract

The invention relates to a storage medium and to a method for using a storage medium based on ionic compounds, which can reversibly absorb and store chlorine and chlorine from process gases, and which can release the same again by changing the ambient conditions, wherein the storage medium can be reused for this task after discharge.

First claim

1 .- 18 . (canceled)

19 . A storage medium serving as a chlorine store for the reversible absorption of chlorine from chlorine-containing gas, comprising at least one ionic compound of the general formula (I) and/or (II),
N—R1 m R2 n R3 o + Cl r −   (I)
P—R4 p R5 q + Cl s −   (II)
in which the radicals R1, R2, R3, R4, and R5 are independently identical or different alkyl radicals selected from the following group: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and 2-methylpropyl, wherein at least one radical R1, R2 or R3 is different from the respective other radicals R1, R2, and R3 and that the radicals R4 and R5 are different from one another, where m, n, o, p, and q are independently an integer in the series from 0 to 3 and where the sum m+n+o and the sum p+q must result in a value of 4, r and s are independently an odd number from 1 to 7, and where the storage medium is liquid within the working range of loading with chlorine and unloading of chlorine, at a temperature of 25° C. and a pressure of 1000±100 hPa.

20 . The storage medium as claimed in claim 19 , wherein, in the compound of general formula (I), m and n are 1, 2, 3 and o is 0.

21 . The storage medium as claimed in claim 19 , wherein the ionic compound (I) or (II) is selected from at least one compound of the following series: NEtMe 3 Cl r , NEt 2 Me 2 Cl r , NEt 3 MeCl r , NBuEt 2 MeCl r , NMePr 3 Cl r , NBu 2 Me 2 Cl r , PEt 3 MeCl s , where r and s are independently an odd number from 1 to 7 and r and s are independently 1 or 3.

22 . The storage medium as claimed in claim 19 , wherein compound (I) is selected from at least one compound of the following series: NEtMe 3 Cl r , NEt 2 Me 2 Cl r , NEt 3 MeCl r , where r is a number ≥1 to ≤7 and r and s are ≥1 to ≤3.

23 . A storage medium for the reversible absorption of chlorine from chlorine-containing gas, comprising at least one ionic compound of the formula (I) and/or of the formula (II) as claimed in claim 19 , wherein the ionic compounds of the formula (I) and/or of the formula (II) contained therein are brought into contact with chlorine at ambient pressure (ambient atmospheric pressure, of 1 bar (1000 hPa) at sea level), and the ionic compounds react to form polychlorides of the formula (III) and/or of the formula (IV),
N—R1 m R2 n R3 o + Cl (r+2) −   (III)
P—R4 p R5 q + Cl (s+2) −   (IV)
where r and s are independently an odd number from 1 to 7.

24 . The storage medium as claimed in claim 19 , wherein the storage medium in the loaded state contains at least 0.65 g of Cl 2 per g of ionic compound.

25 . The storage medium as claimed in claim 19 , wherein the storage medium in the loaded state is liquid at a temperature of 25° C. and a pressure of 1000 t 100 hPa.

26 . The storage medium as claimed in claim 19 , wherein the storage medium when fully loaded with chlorine has at a temperature of 25° C. and a pressure of 1000 hPa a dynamic viscosity of not more than 250 mPa·s, and, independently thereof, the dynamic viscosity of the storage medium in the unloaded state is not more than 400 mPa·s.

27 . A process for removing chlorine from chlorine-containing gas, wherein the gas is contacted with a liquid storage medium comprising ionic compounds of the formula (I) and/or of the formula (II), with the chlorine contained in the gas bound in the form of ionic compounds of the formula (III) and/or of the formula (IV).
N—R1 m R2 n R3 o + Cl (r+2) −   (III)
P—R4 p R5 q + Cl (s+2) −   (IV)
in which the radicals R1, R2, R3, R4, and R5 are independently identical or different alkyl radicals selected from the following group: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and 2-methylpropyl, wherein at least one radical R1, R2 or R3 is different from the respective other radicals R1, R2, and R3 and that the radicals R4 and R5 are in each case different from one another, where in, n, o, p, and q are independently an integer in the series from 0 to 3 and where the sum m+n+o and the sum p+q must result in a value of 4, r and s are independently an odd number from 1 to 7 and r and s are independently 1 or 3.

28 . The process as claimed in claim 27 , wherein, in a first step as conditioning, the storage medium comprising compounds of the formula (I) and/or of the formula (II), where r and s=1, becomes loaded with chlorine gas only to such an extent that the storage medium liquefies.

29 . The process as claimed in claim 28 , wherein conditioning with chlorine takes place to such an extent that a storage medium of the formula (I) and/or of the formula (II) is obtained, where r and s are independently an odd number from 1 to 7 and r and s are independently 1 or 3, and where the storage medium is not fully loaded with chlorine.

30 . The process as claimed in claim 28 , wherein, in a second step after conditioning, chlorine is removed from chlorine-containing gas through contacting with the liquid storage medium from the first step, as a result of which the storage medium becomes loaded and the compounds of the formula (I) and/or of the formula (II) react to form ionic compounds of the formula (III) or (IV).

31 . The process as claimed in claim 27 , wherein the second step, the loading of the storage medium, takes place at a temperature in a range from ≥0° C. to ≤40° C., and a pressure within a range from ≥900 hPa to ≤7000 hPa.

32 . A process for the reversible storage of chlorine from chlorine-containing gas in a storage medium, wherein, in a first step, a removal as claimed in claim 27 is executed and that, in a further process step, stored chlorine is removed from the loaded storage medium by increasing the temperature of the storage medium and/or lowering the partial pressure above the storage medium, with discharge of the chlorine obtained.

33 . The process as claimed in claim 32 , wherein the removal of chlorine through unloading of the reversible storage medium takes place at a temperature within a range from ≥40° C. to ≤200° C., and at a pressure within a range of 1000±100 hPa.

34 . The process as claimed in claim 32 , wherein the removal of chlorine is initiated through reducing the partial pressure by at least 100 hPa compared to the first step.

35 . The process as claimed in claim 32 , wherein at least 0.10 g of chlorine per g of ionic compound, is released from the storage medium during this process.

36 . A method comprising utilizing the storage medium as claimed in claim 19 for removing chlorine from chlorine-containing gases or as a reversible chlorine storage material for filling storage containers for chlorine.

Assignees

• Covestro Intellectual Property Gmbh & Co Kg

Inventors

• Paven Maxime
• Schiesser Yuliya
• Weber Rainer
• Langstein Gerhard
• Trieu Vinh
• Hasenstab-Biedel Sebastian
• Schwarze Nico
• Steinhauer Simon

Classifications

• B01D2252/30

  Ionic liquids and zwitter-ions · CPC title

• B01D53/1425

  Regeneration of liquid absorbents · CPC title

• B01D2257/2025

  Chlorine · CPC title

• B01D2252/205

  Other organic compounds not covered by B01D2252/00 - B01D2252/20494 · CPC title

• F17C11/00

  Use of gas-solvents or gas-sorbents in vessels {(absorbing compositions for acetylene C10L3/04; absorbing compositions for hydrogen C01B3/0005)} · CPC title