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CN-122003287-A - Method for separating chlorine from chlorine-containing gases and reversibly storing chlorine and storage medium for storing chlorine for use in said method

CN122003287ACN 122003287 ACN122003287 ACN 122003287ACN-122003287-A

Abstract

The present invention relates to a process for separating and storing (loading) chlorine Cl 2 from a Cl 2 -containing gas, in particular a Cl 2 -containing process gas, by contacting a Cl 2 -containing gas with at least one polymer compound of formula (I) comprising a polymer having at least one alkylated cationic quaternary amino moiety and at least one chloride anion per alkylated quaternary amino moiety Wherein R 1 、R 2 、R 3 is independently of one another a C1-C4 alkyl moiety, preferably selected from the group of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and sec-butyl, wherein the R 1 、R 2 、R 3 moieties may be the same or different from one another, wherein a, b, C are independently of one another 0, 1,2 or 3, wherein the sum of a+b+c must be 3, wherein Cl 2 from a Cl 2 -containing gas is bound by at least one polymer compound of the general formula (I), thereby providing a polymer compound of the general formula (II) Where n >0, preferably n > =1, preferably n is 1 to 4.

Inventors

  • Sebastian Hassenstab Riedel
  • Merlin Cleoff
  • Patrick Fosnak
  • Fabio Lorenz
  • Reina Hager
  • Olaf Wagner
  • Alejandro Lorent
  • Florian Junge
  • Christian Zoster

Assignees

  • 柏林自由大学

Dates

Publication Date
20260508
Application Date
20241030
Priority Date
20231030

Claims (19)

  1. 1. A process for separating and storing (loading) chlorine Cl 2 from a Cl 2 -containing gas, in particular a Cl 2 -containing process gas, by contacting the Cl 2 -containing gas with at least one polymer compound of the general formula (I), The at least one polymer compound of formula (I) comprises a polymer having at least one alkylated cationic quaternary amino moiety and each alkylated quaternary amino moiety having at least one chloride anion Wherein R 1 、R 2 、R 3 is independently of one another a C1-C4 alkyl moiety, preferably selected from the group of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and sec-butyl, Wherein the R 1 、R 2 、R 3 moieties may be the same or different from each other, Wherein a, b, c are each independently of the other 0, 1, 2 or 3, wherein the sum a+b+c must be 3, Wherein the chlorine Cl 2 from the Cl 2 -containing gas is bound by the at least one polymer compound of formula (I) to provide a polymer compound of formula (II) Where n >0, preferably n > =1, more preferably n is 1 to 4.
  2. 2. The method according to claim 1, wherein the polymer is an anion exchange resin comprising at least one alkylated cationic quaternary amino moiety, preferably a polystyrene or polyacrylate based resin, more preferably a polyacrylate based resin.
  3. 3. The method of claim 1, wherein the polymer is a Polyethyleneimine (PEI) polymer comprising at least one alkylated quaternary amino moiety.
  4. 4. The method according to one of the preceding claims, characterized in that R 1 、R 2 、R 3 is selected independently of each other from the group of methyl, ethyl, n-propyl, isopropyl.
  5. 5. The process according to one of the preceding claims, characterized in that the polymer compound of the general formula (I) is Or (b) 。
  6. 6. The process according to one of the preceding claims, characterized in that the polymer compound of the general formula (I) is loaded with Cl 2 gas by condensation or in the gas phase.
  7. 7. The process according to one of the preceding claims, characterized in that during the loading of the polymer compound of formula (I) with Cl 2 in the gas phase, the flow rate of the Cl 2 -containing gas is from 10 l/hour to 40 l/hour, preferably from 15 l/hour to 35 l/hour, more preferably from 20 l/hour to 30 l/hour.
  8. 8. The process according to one of the preceding claims, characterized in that the loading of the polymer compound of formula (I) with Cl 2 gas is carried out at a temperature of 10 ℃ to 40 ℃, preferably 20 ℃ to 30 ℃ and a pressure of 0.5 bar to 1.5 bar, preferably 1 bar.
  9. 9. The method according to one of the preceding claims, characterized in that the polymer compound of the general formula (I) is loaded with at least 0.1 g Cl 2 /g polymer compound, preferably at least 0.2 g Cl 2 /g polymer compound, more preferably at least 0.4 g Cl 2 /g polymer compound, even more preferably at least 0.5 g Cl 2 /g polymer compound, still more preferably at least 0.6 g Cl 2 /g polymer compound, and up to at least 0.8 g Cl 2 /g polymer compound.
  10. 10. Storage medium for storing chlorine Cl 2 obtainable by a process according to one of the preceding claims, wherein the storage medium comprises a polymer compound of general formula (II) Wherein R 1 、R 2 、R 3 is independently of one another a C1-C4 alkyl moiety, preferably selected from the group of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and sec-butyl, Wherein the R 1 、R 2 、R 3 moieties may be the same or different from each other, Wherein a, b, c are each independently of the other 0, 1, 2 or 3, wherein the sum a+b+c must be 3, Where n >0, preferably n > =1, more preferably n is 1 to 4.
  11. 11. The storage medium according to claim 10, characterized in that the polymer compound of formula (II) (in loaded state) comprises at least 0.1 g Cl 2 /g polymer compound, preferably at least 0.2g Cl 2 /g polymer compound, more preferably at least 0.4g Cl 2 /g polymer compound, even more preferably at least 0.5 g Cl 2 /g polymer compound, still more preferably at least 0.6 g Cl 2 /g polymer compound, and up to at least 0.8 g Cl 2 /g polymer compound.
  12. 12. Use of a storage medium according to one of the preceding claims 10 to 11 for separating Cl 2 from a process gas and/or for reversibly absorbing and storing Cl 2 from a process gas.
  13. 13. Use of the storage medium according to claim 12 for removing chlorine from a process gas comprising H 2 、CO 2 、O 2 、CO、NO、NO 2 、N 2 O 4 、N 2 、SO 3 , and mixtures thereof.
  14. 14. Use of the storage medium according to one of claims 9 to 10 for chlorinating at least one alkene, thereby providing at least one chlorinated alkane and the polymer compound according to formula (I) as defined in claim 1.
  15. 15. A process for releasing chlorine Cl 2 from a storage medium comprising a polymer compound of the general formula (II) according to one of claims 9 to 10, characterized in that, -Releasing the chlorine Cl 2 stored in the storage medium by increasing the temperature of the storage medium to 60 ℃ and/or by decreasing the partial pressure above the storage medium.
  16. 16. The method according to claim 15, characterized in that the chlorine Cl 2 stored in the storage medium is released at a temperature in the range of 20 ℃ to 80 ℃, preferably 30 ℃ to 70 ℃, more preferably 40 ℃ to 60 ℃.
  17. 17. The method according to one of claims 15 to 16, characterized in that 50% to 95%, preferably 60% to 95%, of the stored chlorine Cl 2 is released by the temperature.
  18. 18. A method comprising at least one cyclic cycle of storing (loading) chlorine Cl 2 in a polymer compound of formula (I) according to one of claims 1 to 9 and providing a storage medium comprising a polymer compound of formula (II) and releasing (unloading) chlorine Cl 2 from said storage medium according to one of claims 15 to 17.
  19. 19. The method according to claim 18, characterized in that the cycle of storing (loading) chlorine Cl 2 in the polymer compound of formula (I) and providing the storage medium comprising the polymer compound of formula (II) can be repeated at least 5 times, preferably at least 7 times.

Description

Method for separating chlorine from chlorine-containing gases and reversibly storing chlorine and storage medium for storing chlorine for use in said method The present invention relates to a method for separating and storing chlorine from chlorine-containing gases, a storage medium for storing chlorine used in the method, a method for releasing chlorine from the storage medium, the use of the storage medium for separating chlorine from process gases and/or for reversible absorption and storage of chlorine, and the use of the storage medium as a chlorinating agent for olefins. Description of the invention Chlorine is one of the most important basic chemicals in the chemical industry, and chlorine is required to produce about 50% of all industrial chemicals, 30% of all agrochemicals, and 20% of all pharmaceuticals. The most important products in the chlorine industry are polymers such as polyvinyl chloride (PVC) or Polyurethane (PU), and substances such as phosphorus trichloride, which are very important for synthetic pesticides and flame retardants. To meet the global chlorine demand of 2021, approximately 9200 ten thousand tons of chlorine are produced mainly by chlor-alkali electrolysis in which sodium chloride is electrolyzed into chlorine and sodium hydroxide. Since chlorine extraction is one of the most energy intensive processes in the chemical industry, where energy demand accounts for about 50% of production costs, 3 thus only german chlorine production requires about 1200 ten thousand MWh, which corresponds to about 2.0% of german electrical energy. Current predictions show that global chlorine production will increase to about 1.19 million tons in the next few years to 2028, and that the power demand for global chlorine production will also increase. About half of the chlorine gas produced in chlor-alkali electrolysis is converted on site and the other half is liquefied to make it suitable for transport. However, it is impossible to completely liquefy chlorine gas by a usual industrial method. Leaving a residual gas stream consisting of about 20% chlorine, 70% air, and 10% hydrogen and water vapor. This portion of the chlorine that cannot be liquefied must be eliminated by the addition of sodium hydroxide, and therefore both the chlorine in the residual gas stream and the sodium hydroxide used for it are lost in the industry. On the other hand, if chlorine can be further separated from the residual gas stream and made available, the productivity of chlor-alkali electrolysis can be increased, and thus the power requirements for chlorine production can be reduced. An established method for separating chlorine from a residual gas stream of chlor-alkali electrolysis is to pass the residual gas stream through carbon tetrachloride (CCl 4). The chlorine content of the residual gas stream can be reduced to 1% due to the high solubility of chlorine of about 0.18 kg Cl 2/kg CCl4 in carbon tetrachloride at 0 ℃ (n.w. Taylor, j.h. Hildebrand, j. Am. chem. Soc. 1923, 45, pages 682 to 694). However, this process releases about 4,000 tons of carbon tetrachloride into the atmosphere each year. In the atmosphere, carbon tetrachloride acts as a greenhouse gas and damages the ozone layer （K. A. Lokhandwala, S. Segelke, P. Nguyen, R. W. Baker, T. T. Su, I. Pinnau, Ind. Eng. Chem. Res. 1999, 38, , pages 3606 to 3613). Because of the high ozone depletion potential of carbon tetrachloride, this process is severely limited by the montreal protocol (Montreal Protocol). Today, only six chlor-alkali electrolysis plants worldwide still use carbon tetrachloride to absorb chlorine from the residual gas stream. Thus, in most plants, chlorine in the residual gas stream is not separated, and the residual gas stream is treated with sodium hydroxide to produce sodium chloride and sodium hypochlorite as waste products. Many membranes have been developed that have a higher permeability to chlorine than to air, thus enabling separation of the chlorine component of the residual gas stream from other gases. However, most of these films show only limited stability in continuous contact with chlorine and thus their industrial applicability is limited （M. S. Eikeland, M.-B. Hagg, M. A. Brook, M. Ottøy, A. Lindbrathen, J. Appl. Polymer Sci. 2002, 85, , pages 2458 to 2470). Typically, chlorine can be irreversibly chemically bound, for example, by reacting the chlorine with an olefin-based organometallic casting (cast), but the bound chlorine cannot be used elsewhere (t.j. Azbell, r.m. Mandel, j. -h.lee, p.j. Milner, ACS appl, mate, interfaces 2022, 14, pages 53982 to 53935). WO2007109611A1 describes a method for the safe storage and transport of chlorine at ambient pressure. Chlorinated 1-methyl-3-ethylimidazolesAnd pyridine hydrochloride are preferred. Also mentioned are tetraalkylammonium chlorides and tetraalkylammonium chlorides。 WO2012130803A1 describes a process for removing halogen from mixtures of substances (CO, CO 2、N2, methyl isocy