DEVICE FOR GENERATING OXYGEN FROM PEROXIDES IN IONIC LIQUIDS

Abstract

The present invention is directed to a device for generating oxygen, comprising at least one oxygen source, at least one ionic liquid, and at least one metal salt, wherein the oxygen source comprises a peroxide compound, the ionic liquid is in the liquid state at least in a temperature range from 10 C. to +50 C., and the metal salt has an organic and/or an inorganic anion, and comprises one single metal or two or more different metals. The present invention also relates to charge components for filling or refilling the devices, and to the use of ionic liquids as dispersants or solvents for the reaction participants.

Claims

1. A device for generating oxygen comprising: at least one reaction chamber for housing a composition for generating oxygen, the composition comprising a combination of constituents consisting of at least one oxygen source, at least one ionic liquid, and at least one metal salt; means for maintaining at least one of the oxygen source, the ionic liquid and the metal salt physically separated from the remaining constituents; means for establishing physical contact of the oxygen source, the ionic liquid and the metal salt; and means for allowing oxygen to exit the reaction chamber; wherein the metal salt comprises a single metal or two or more different metals, and an organic and/or an inorganic anion; and wherein the oxygen source comprises a peroxide compound.

2. The device according to claim 1, wherein the oxygen source is selected from: alkali metal percarbonates, alkali metal perborates, urea hydrogen peroxide, and mixtures thereof.

3. The device according to claim 1, wherein the oxygen source is one or more of Na.sub.2CO.sub.31.5 H.sub.2O.sub.2, NaBO.sub.34H.sub.2O, NaBO.sub.3H.sub.2O and urea hydrogen peroxide.

4. The device according to claim 1, wherein the ionic liquid is at least one salt having a cation and an anion, wherein the cation is selected from the group consisting of: imidazolium, pyrrolidinium, ammonium, pyridinium, pyrazolium, piperidinium, phosphonium, and sulfonium cations.

5. The device according to claim 1, wherein the ionic liquid is at least one salt having a cation and an anion, wherein the anion is selected from the group consisting of: dimethylphosphate, methylsulfate, ethylsulfate, trifluoromethylsulfonate, bis(trifluoromethylsulfonyl)imide, chloride, bromide, iodide, tetrafluoroborate, hexafluorophosphate, acetate, and but-3-enoate.

6. The device according to claim 1, wherein the ionic liquid is selected from the group consisting of: 1-butyl-3-methylimidazoliumdimethylphosphate (BMIMPO.sub.4Me.sub.2), 1,3-dimethylimidazoliumdimethylphosphate (MMIMPO.sub.4Me.sub.2), 1-butyl-3-methylimidazoliumacetate (BMIMOAc), 1-ethyl-3-methylimidazoliumethylsulfate (EMIMEtSO.sub.4), and tetraethylammonium but-3-enoate (NEt.sub.4but-3-enoate).

7. The device according to claim 1, wherein the metal salt is soluble or partially soluble, or insoluble in the ionic liquid.

8. The device according to claim 1, wherein the metal salt contains one single metal, the metal being selected from the metals belonging to groups 5 to 14 and periods 4 to 6 of the periodic table of the elements.

9. The device of claim 8, wherein the metal has different oxidation states.

10. The device according to claim 1, wherein the metal salt comprises at least two different metals, with at least one metal being selected from the metals belonging to groups 5 to 14 and periods 4 to 6 of the periodic table of the elements.

11. The device according to claim 1, wherein the metal salt comprises at least one cation selected from the group consisting of vanadium, chromium, manganese, iron, cobalt, copper, molybdenum, ruthenium, iridium, and lead.

12. The device according to claim 1, wherein the metal salt is selected from the group consisting of: chlorides, sulfates, carbonates, nitrates, phosphates, hydroxides, and mixtures thereof, or from the group consisting of acetates, acetylacetonates, oxalates, tartrates, citrates, and mixtures thereof.

13. The device according to claim 1, as a component unit of a self-rescuer, a rebreather, a welding device or a control nozzle.

14. A charge component set for a device for generating oxygen as claimed in claim 1, the charge component set comprising: an oxygen source formulation, an ionic liquid formulation, and a metal salt formulation, wherein: the oxygen source formulation comprises a peroxide compound; the ionic liquid formulation is in the liquid state at least in a temperature range from 10 C. to +50 C.; and the metal salt formulation comprises a metal salt which comprises one single metal or two or more different metals, and an organic or inorganic anion.

15. The charge component set according to claim 14, wherein the oxygen source formulation comprises alkali metal percarbonates, alkali metal perborates, urea hydrogen peroxide, and mixtures thereof.

16. The charge component set according to claim 14, wherein the ionic liquid formulation comprises: at least one salt having a cation and an anion, wherein the cation is selected from the group consisting of: imidazolium, pyrrolidinium, ammonium, pyridinium, pyrazolium, piperidinium, phosphonium, and sulfonium cations; and wherein the anion is selected from the group consisting of: dimethylphosphate, methylsulfate, ethyl sulfate, trifluoromethylsulfonate, bis(trifluoromethylsulfonyl)imide, chloride, bromide, iodide, tetrafluoroborate, hexafluorophosphate, acetate, and but-3-enoate; or wherein the ionic liquid is selected from the group consisting of: 1-butyl-3-methylimidazoliumdimethylphosphate (BMIMPO.sub.4Me.sub.2), 1,3-dimethylimidazoliumdimethylphosphate (MMIMPO.sub.4Me.sub.2), 1-butyl-3-methylimidazoliumacetate (BMIMOAc), 1-ethyl-3-methylimidazoliumethylsulfate (EMIMEtSO.sub.4), and tetraethylammonium but-3-enoate (NEt.sub.4but-3-enoate).

17. The charge component set according to claim 14, wherein metal salt formulation contains one single metal, the metal being selected from the metals belonging to groups 5 to 14 and periods 4 to 6 of the periodic table of the elements

18. A use of an ionic liquid as a dispersant or solvent and as a heat sink in a composition for generating oxygen, the composition further comprising: at least one oxygen source formulation, and at least one metal salt formulation, wherein the oxygen source formulation comprises a peroxide compound, the ionic liquid is in the liquid state at least in a temperature range from 10 C. to +50 C., and the metal salt formulation comprises a metal salt which comprises one single metal or two or more different metals, and an organic and/or inorganic anion.

19. The use according to claim 18, wherein the oxygen source formulation comprises a peroxide compound as defined in claim 2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0192] The invention will be further illustrated by the following non-limiting examples with reference to the accompanying drawings, wherein:

[0193] FIG. 1 is a graph illustrating oxygen release from different amounts of UHP by MnCl.sub.2 in BMIMOAc,

[0194] FIG. 2 is a graph illustrating reaction temperatures for the decomposition reactions illustrated in FIG. 1,

[0195] FIG. 3 is a graph illustrating oxygen release from different amounts of UHP by Mn(OAc).sub.3 in BMIMOAc,

[0196] FIG. 4 is a graph illustrating reaction temperatures for the decomposition reactions illustrated in FIG. 3,

[0197] FIG. 5 is a graph illustrating oxygen release from UHP in different ionic liquids by catalytic amounts of IrCl.sub.3,

[0198] FIG. 6 is a graph illustrating oxygen release from UHP in different ionic liquids by catalytic amounts of Co(OAc)2,

[0199] FIGS. 7 and 8 are graphs illustrating oxygen release from UHP in BMIMOAc by different inorganic metal salts,

[0200] FIGS. 9 and 10 are graphs illustrating oxygen release from UHP in BMIMIOAc by different organic metal salts,

[0201] FIG. 11 is a graph illustrating oxygen release from UHP in BMIMOAc by different concentrations of MnCl.sub.2,

[0202] FIG. 12 is a graph illustrating oxygen release from UHP in BMIMOAc by different concentrations of Mn(OAc).sub.2,

[0203] FIG. 13 is a graph illustrating oxygen release from mixtures of SPC and UHP in MMIMPO.sub.4Me.sub.2 by CoSO.sub.4,

[0204] FIG. 14 is a graph illustrating oxygen release from SPC in BMIMOAc by COSO.sub.4,

[0205] FIG. 15 is a graph illustrating oxygen release from UHP and from mixtures of UHP and SPC in BMIMOAc by Mn(OAc).sub.3,

[0206] FIG. 16 is a graph illustrating oxygen release from SPC in BMIMOAc by Co(OAc).sub.2,

[0207] FIG. 17 illustrates oxygen release from UHP powder and from mixtures of UHP powder and UHP powder compacts in BMIMOAc by Mn(OAc).sub.3,

[0208] FIG. 18 illustrates oxygen release from UHP in BMIMOAc and MMIMPO.sub.4Me.sub.2 by different insoluble or partially soluble inorganic metal salts,

[0209] FIG. 19 illustrates oxygen release from UHP in MMIMPO.sub.4Me.sub.2 by different insoluble or partially soluble organic metal salts, and

[0210] FIGS. 20 to 24 schematically illustrate several embodiments of devices for generating oxygen from compositions according to the invention.

DETAILED DESCRIPTION

[0211] In all graphs illustrating oxygen release or reaction temperature, oxygen release (or reaction temperature, respectively) is plotted against runtime, wherein runtime is the time which starts running at the time point of contacting the oxygen source, the ionic liquid and the catalyst. In the tables, volume is the oxygen volume released in total, and time is the time until complete release of the releasable oxygen.

Example 1

[0212] Urea hydrogen peroxide (UHP) adducts in the amounts listed in table 1 were added to solutions of 0.5 mol % (relative to UHP) MnCl.sub.2 in BMIMOAc (amounts listed in table 1) contained in a glass flask. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. In addition, the reaction temperature was measured. The results are illustrated in FIGS. 1 and 2.

TABLE-US-00001 TABLE 1 peroxide mass 2 1 g 13.4 mg 155 ml 1.30 min 5 2.5 g 33.5 mg 345 ml 5.78 min 10 5 g 67.0 mg 1205 ml 11.94 min 20 10 g 134.0 mg 2810 ml 9.84 min

[0213] FIG. 1 shows that when varying amounts of peroxide compound are added to equivalently varying amounts of an ionic liquid and a soluble metal salt having an inorganic anion as a catalyst, the amount of oxygen released by the decomposition reaction increases essentially proportionally, thus proving that the decomposition reaction is scalable for different sizes of devices for generating oxygen.

[0214] FIG. 2 shows that the reaction temperatures increase with increasing amounts of reaction mixture, but remain below 100 C. even for the sample containing 20 g UHP.

Example 2

[0215] Urea hydrogen peroxide (UHP) adduct in the amounts listed in table 2 was added to solutions of 1.25 mol % (relative to UHP) Mn(OAc).sub.3 in BMIMOAc (amounts listed in table 2) contained in a glass flask. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. In addition, the reaction temperature was measured. The results are illustrated in FIGS. 3 and 4.

TABLE-US-00002 TABLE 2 peroxide mass mass IL mass catalyst volume tim UHP 6 g 3 g 213.8 mg 405 ml 7.87 min UHP 10 g 5 g 365.3 mg 910 ml 10.16 min UHP 14 g 7 g 498.8 mg 1520 ml 12.80 min UHP 20 g 10 g 712.5 mg 2685 ml 15.42 min

[0216] FIG. 3 shows that when varying amounts of a peroxide compound are added to equivalently varying amounts of an ionic liquid and a soluble metal salt having an organic anion as a catalyst, the amount of oxygen released by the decomposition reaction increases proportionally, thus proving that the decomposition reaction is scalable for different sizes of devices for generating oxygen.

[0217] FIG. 4 shows that the reaction temperatures increase with increasing amounts of reaction mixture, but remain below 120 C. even for the sample containing 20 g UHP.

Example 3

[0218] 2.0 g urea hydrogen peroxide adduct compound (UHP) were added to a solution of 2 mol % (relative to UHP) IrCl3 catalyst in 1.0 g of different ionic liquids (IL) contained in a glass flask each. The ionic liquids used are listed below. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The results are listed in table 3, and are illustrated in FIG. 5.

[0219] Ionic Liquids: [0220] 1-butyl-3-methylimidazoliumdimethylphosphate (BMIMPO.sub.4Me.sub.2) [0221] 1,3-dimethylimidazoliumdimethylphosphate (MMIMPO.sub.4Me.sub.2) [0222] 1-butyl-3-methylimidazoliumacetate (BMIMOAc) [0223] tetraethylammonium but-3-enoate (NEt.sub.4but-3-enoate)

TABLE-US-00003 TABLE 3 peroxide mass adduct IL catalyst volume time UHP BMIMPO.sub.4Me.sub.2 127 mg 20 ml 80 min UHP MMIMPO.sub.4Me.sub.2 127 mg 10 ml 40 min UHP BMIMOAc 127 mg 170 ml 1.21 min UHP NEt.sub.4but-3-enoate 127 mg 45 ml 60 min

[0224] In the cases of BMIMPO.sub.4Me.sub.2, MMIMPO.sub.4Me.sub.2, and NEt.sub.4but-3-enoate the reaction was terminated after 80 minutes, 40 minutes, and 60 minutes, respectively, although not complete.

[0225] FIG. 5 reveals that the ionic liquid used as a solvent has a pronounced influence on the reaction speed of the decomposition reaction, on the amount of oxygen released, and also on the time of onset of the decomposition reaction.

Example 4

[0226] 2.0 g urea hydrogen peroxide adduct compound (UHP) were added to a solution of 0.25 mol % (relative to UHP) Co(OAc).sub.2 catalyst in 1.0 g of different ionic liquids (IL) contained in a glass flask each. The ionic liquids used are listed below. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The results are listed in table 4, and are shown in FIG. 6

[0227] Ionic Liquids: [0228] 1-butyl-3-methylimidazoliumdimethylphosphate (BMIMPO.sub.4Me.sub.2) [0229] 1,3-dimethylimidazoliumdimethylphosphate (MMIMPO.sub.4Me.sub.2) [0230] 1-butyl-3-methylimidazoliumacetate (BMIMOAc) [0231] 1-ethyl-3-methylimidazoliumethylsulfate (EMIMEtSO.sub.4)
tetraethylammonium but-3-enoate (NEt.sub.4but-3-enoate)

TABLE-US-00004 TABLE 4 peroxide mass adduct IL catalyst volume tim UHP BMIMPO.sub.4Me.sub.2 13.3 mg 90 ml 30.0 min UHP MMIMPO.sub.4Me.sub.2 13.3 mg 125 ml 3.15 min UHP BMIMOAc 13.3 mg 310 ml 1.90 min UHP EMIMEtSO.sub.4 13.3 mg 10 ml 30.0 min UHP NEt.sub.4but-3-enoate 13.3 mg 75 ml 1.34 min

[0232] In the cases of BMIMPO.sub.4Me.sub.2 and EMIMEtSO.sub.4 the reaction was terminated after 30 minutes, although not complete.

[0233] FIG. 6 reveals that the ionic liquid used as a solvent has a pronounced influence on the reaction speed of the decomposition reaction and on the amount of oxygen released by the decomposition reaction. The ionic liquid also exerts some influence on the time when the decomposition reaction starts.

Example 5

[0234] 2.0 g UHP were added to solutions of different inorganic metal salts in 1.0 g BMIMOAc contained in a glass flask. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The types and amounts of catalysts used are listed in table 5, and some of the reaction profiles of the decomposition reaction are shown in FIGS. 7 and 8.

TABLE-US-00005 TABLE 5 peroxide catalyst mass catalyst volume UHP PbCl.sub.2 118.3 mg 295 ml UHP CrCl.sub.3 113.3 mg 650 ml UHP K.sub.2Cr.sub.2O.sub.7 183.7 mg 565 ml UHP CoCl.sub.2 101.2 mg 295 ml UHP CoCO.sub.3 50.6 mg 320 ml UHP CoSO.sub.4 119.5 mg 285 ml UHP IrCl.sub.3 127.0 mg 165 ml UHP MnCl.sub.2 53.5 mg 310 ml UHP VCl.sub.2 103.6 mg 440 ml UHP KCr(SO.sub.4).sub.2 212.3 mg 590 ml UHP FeCl.sub.2 123.6 mg 390 ml UHP FeCl.sub.3 114.9 mg 380 ml UHP Fe(NO.sub.3).sub.3 42.9 mg 275 ml UHP CuCl.sub.2 57.2 mg 460 ml

[0235] FIGS. 7 and 8 reveal that the catalyst has an influence on the amount of oxygen released, on the reaction speed, and also on the time of onset of the decomposition reaction.

Example 6

[0236] 2.0 g UHP were added to solutions of different organic metal salts in 1.0 g BMIMOAc contained in a glass flask. This flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The types and amounts of catalysts used are listed in table 6, and some of the reaction profiles are shown in FIGS. 9 and 10.

TABLE-US-00006 TABLE 6 peroxide catalyst mass catalyst volume UHP Mn(OAc).sub.2 104.2 mg 320 ml UHP Mn(OAc).sub.3 114.0 mg 250 ml UHP Mn(acac).sub.2 107.6 mg 300 ml UHP Mn(oxalate) 76.1 mg 75 ml UHP Pb(acac).sub.2 172.4 mg 210 ml UHP Pb(OAc).sub.2 161.3 mg 305 ml UHP Pb(OAc).sub.4 188.5 mg 15 ml UHP Pb3(citrate).sub.2 149.4 mg 20 ml UHP Pb(tartrate) 151.1 mg 15 ml UHP Co(OAc).sub.2 13.3 mg 310 ml UHP MoO2(acac).sub.2 138.7 mg 395 ml UHP Ru(acac).sub.3 63.5 mg 135 ml

[0237] FIGS. 9 and 10 reveal that the amount of oxygen released by decomposition reaction strongly depends on the particular catalyst used. The catalyst also influences the reaction speed of the decomposition reaction.

Example 7

[0238] 2.0 g UHP were added to solutions of different amounts of MnCl.sub.2 catalysts in 1.0 g BMIMOAc contained in a glass flask. The amounts and concentrations (relative to UHP) of MnCl.sub.2 are indicated in table 7. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The reaction profiles are shown in FIG. 11.

TABLE-US-00007 TABLE 7 peroxide adduct mass/concentration volume time UHP 13.4 mg 130 ml 10 min UHP 26.8 mg 165 ml 10 min UHP 53.5 mg 310 ml 2.62 min UHP 107 mg 305 ml 1.66 min

[0239] In the cases of 0.5 mol % and 1 ml % catalyst the reaction was terminated after 10 minutes.

[0240] FIG. 11 reveals that the catalyst concentration exerts a strong influence on the reaction velocity, the onset of the decomposition reaction, and on the amount of oxygen released. On the other hand, there is a catalyst saturation concentration, i.e. the amount of oxygen which can be produced is limited by the amount of oxygen available. Even very high amounts of catalyst can not achieve more than decompose the peroxide completely.

Example 8

[0241] 5.0 g UHP were added to solutions of different amounts of Mn(OAc).sub.2 catalysts in 2.5 g BMIMOAc contained in a glass flask. The amounts and concentrations (releative to UHP) of Mn(OAc).sub.2 are indicated in table 8. The flask was closed, and the oxygen volume released by the decomposition reactions was measured with a drum gas meter. The reaction profiles are shown in FIG. 12.

TABLE-US-00008 TABLE 8 mass/concentration peroxide adduct catalyst volume time UHP 92.0 mg 345 ml 6.96 min UHP 114.9 mg 635 ml 5.22 min UHP 138.0 mg 725 ml 4.43 min UHP 183.9 mg 740 ml 3.27 min

[0242] FIG. 12 reveals that the catalyst concentration influences the reaction speed of the decomposition reaction, and exerts a strong influence on the amount of oxygen released. However, there is a saturation concentration. The amount of oxygen released is, of course, limited by the amount of oxygen provided by the amount of peroxide adduct compound.

Example 9

[0243] Mixtures of UHP and sodiumpercarbonate (SPC) in the amounts listed in table 9 (total amount 2.0 g) were added to solutions of CoSO.sub.4 in 1 g MMIMPO.sub.4Me.sub.2. Then, the reaction vessel was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The results are illustrated in FIG. 13.

[0244] In the same manner, 2.00 g SPC was added to a solution of 107.4 mg CoSO.sub.4 in 1 g BMIMOAc (2 mol % catalyst relative to SPC). The reaction profile is shown in FIG. 14.

TABLE-US-00009 TABLE 9 mass UHP masse SPC mass catalyst volume time 1.25 g 0.75 g 13.4 mg 240 ml 0.98 min 1.00 g 1.00 g 13.4 mg 210 ml 1.14 min 0.75 g 1.25 g 13.4 mg 180 ml 1.44 min 0.50 g 1.50 g 13.4 mg 145 ml 2.23 min 0.25 g 1.75 g 13.4 mg 30 ml 10 min / 2.00 g 107.4 mg 32 ml 840 min

[0245] It is evident from FIGS. 13 and 14, that the nature of the peroxide compound influences the velocity of the decomposition reaction, and the amount of oxygen released. As an oxygen source, UHP is clearly preferable over SPC, since the amount of oxygen released increases with increasing UHP ratio.

Example 10

[0246] Urea hydrogen peroxide (UHP) and mixtures of UHP and sodiumpercarbonate (SPC) in the amounts listed in table 10 were added to solutions of 35.6 mg (0.5 mol % relative to the peroxide compound) Mn(OAc).sub.3 in 2.5 g BMIMOAc. Then, the reaction vessel was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The results are illustrated in FIG. 15.

[0247] In the same manner, 2 g SPC were added to a solution of 105.9 mg (2 mol % relative to SPC) Co(OAc).sub.2 in 1 g BMIMOAc. The reaction profile is shown in FIG. 16.

TABLE-US-00010 TABLE 10 mass UHP mass SPC mass catalyst volume tim 5 g / 35.6 mg 365 ml >30 min 3.5 g 1.67 g 35.6 mg 580 ml 5.08 min 2 g 3.34 g 35.6 mg 425 ml 3.08 min 1 g 4.45 g 35.6 mg 390 ml 4.52 min

[0248] It is evident from FIGS. 15 and 16 that the nature of the peroxide compound influences the course of the decomposition reaction. In principle, it appears that UHP as an oxygen source is preferable over SPC because the amount of oxygen released increases with increasing UHP ratio. From pure UHP, however, less oxygen is released than from mixtures of UHP and SPC. At least, the reaction speed is considerably delayed.

Example 11

[0249] In a first experiment, 10 g UHP in powder form were added to a solution of 1.25 mol % (relative to UHP) Mn(OAc).sub.3 in 5 g BMIMOAc contained in a glass flask.

[0250] In a second experiment, 4 g UHP powder, which was used in experiment 1, were substituted by compressed (compaction pressure about 220 MPa) UHP tablets weighing 1 g each. The tablets and 6 g of the same UHP powder of experiment 1 were added to a solution of Mn(OAc).sub.3 in BMIMOAc, as used in experiment 1.

[0251] In a third experiment, 6 g of the same UHP powder, which was used in experiment 1, were substituted by compressed (compaction pressure about 220 MPa) UHP tablets weighing 1 g each. The tablets and 4 g of the same UHP powder which was used in experiment 1, were added to a solution of Mn(OAc).sub.3 in BMIMOAc, as used in experiment 1.

[0252] The flasks were closed, and the oxygen volumes released by the decomposition reactions were measured with a drum gas meter. The results are shown in table 11 and FIG. 17.

TABLE-US-00011 TABLE 11 peroxide mass adduct peroxide mas mass volume time UHP 1 powder 5 229.8 mg 1500 ml 3.71 min UHP 10 g (4 g 5 229.8 mg 1380 ml 7.08 min tablets) UHP 10 g (6 g 5 229.8 mg 1245 ml 9.10 min tablets)

[0253] The reaction speed was reduced and the time of oxygen production was somewhat extended, respectively, by compacting the hydrogen peroxide adduct compound.

Example 12

[0254] In this example, inorganic metal salts, which were insoluble in the respective ionic liquids of the compositions for generating oxygen, were used.

[0255] 2.0 g UHP were added to dispersions of different metal salts in 1.0 g ionic liquid contained in a glass flask. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The ionic liquids and the type and amounts of catalysts used are listed in table 12, and the reaction profiles are shown in FIG. 18.

TABLE-US-00012 TABLE 12 peroxide mass adduct catalyst catalyst Ionic IL volume UHP KCr(SO.sub.4).sub.2 212.3 mg [BMIM][OAc] 580 ml UHP PbSO.sub.4 193.5 mg [BMIM][OAc] 210 ml UHP VCl.sub.2 103.6 mg [BMIM][OAc] 440 ml UHP CuCl 57.2 mg [MMIM][PO.sub.4Me.sub.2] 460 ml UHP FePO.sub.4 21.8 mg [BMIM][OAc] 12.5 ml

[0256] FIG. 18 reveals that the insoluble metal salt catalysts behave similar to the soluble metal salt catalysts. The onset of the decomposition reaction, the reaction velocity, and the total amount of oxygen released depend on the particular catalyst used.

Example 13

[0257] In this example, organic metal salts, which were insoluble in the ionic liquid of the composition for generating oxygen, were used.

[0258] 2.0 g UHP were added to dispersions of different metal salts in 1.0 g MMIMPO.sub.4Me.sub.2 contained in a glass flask. The flask was closed, and the oxygen volume released by the decomposition reaction was measured with a drum gas meter. The type and amounts of the catalysts used are listed in table 13, and the reaction profiles are shown in FIG. 19.

TABLE-US-00013 TABLE 13 peroxide mass adduct catalyst catalyst mass IL volume UHP Pb(acac).sub.2 172.4 mg [MMIM][PO.sub.4Me.sub.2] 180 ml UHP Pb(OAc).sub.22 171.7 mg [MMIM][PO.sub.4Me.sub.2] 255 ml Pb(OH).sub.2 UHP Ru(acac).sub.3 65.0 mg [MMIM][PO.sub.4Me.sub.2] 280 ml

[0259] FIG. 19 reveals that the insoluble metal salt catalysts behave similar to the soluble metal salt catalysts. The onset of the decomposition reaction and the total amount of oxygen released depend on the particular catalyst used.

[0260] An exemplary device for generating oxygen from compositions as described above which use ionic liquids for dissolving or dispersing a hydrogen peroxide adduct compound as an oxygen source, and for dispersing or dissolving a catalyst and bringing the catalyst into contact with the oxygen source, is specifically designed. An exemplary device for generating oxygen has at least one reaction chamber for storing the composition in a condition where not all constituents of the composition are in physical contact. Such physical contact of all constituents of the composition is established at the very moment when oxygen is required. The device is equipped with suitable means for allowing the constituents to contact each other at that very moment. Furthermore, the device allows that the generated oxygen exits the reaction chamber. Some exemplary devices are illustrated in FIGS. 20 to 24, wherein like reference numerals designate like components. The description of such exemplary embodiments shall not be construed as limiting the invention in any manner.

[0261] FIG. 20 illustrates an exemplary device for generating oxygen 1 having one single reaction chamber 2 for storing the composition for generating oxygen. In such a single reaction chamber 2 at least one of the constituents of the composition for generating oxygen must be enclosed in a receptacle in order to avoid contact with the remaining constituents of the composition contained in the reaction chamber 2. In the embodiment shown in FIG. 20, two receptacles 5, 6 are arranged in the reaction chamber. Receptacle 5 contains an intimate mixture of the oxygen source 7 and the decomposition catalyst 9, for example in powder form or compressed into pellets, in a thoroughly dried condition. Receptacle 6 contains the ionic liquid 8. Alternatively, there may be only one receptacle for enclosing the peroxide/catalyst mixture, while the ionic liquid is free within reaction chamber 2, or ionic liquid 8 may be enclosed within a receptacle, while the peroxide/catalyst mixture is not enclosed in a separate receptacle. Further alternatively, the catalyst may be dissolved (soluble metal salts) or partly dissolved (partly soluble metal salts) or dispersed (insoluble metals salts) in the ionic liquid. The alternative is particularly advantageous. It is, in principle, also possible to enclose only the catalyst within a separate receptacle, while the ionic liquid and the peroxide are not enclosed. It is only necessary to avoid contact between all three constituents during storage of the device for generating oxygen.

[0262] It is desirable to store the peroxide 7, the ionic liquid 8 and the catalyst 9 within the reaction chamber 2 in such an arrangement that all constituents will be able to get intimately mixed once oxygen generation is required. When, for example, an insoluble or only partly soluble metal salt is used as a catalyst, and this catalyst and the ionic liquid are provided in one receptacle, and the peroxide in another receptacle, the catalyst may settle within the ionic liquid during storage. In such a case proper mixing with the peroxide may be inhibited. Quick and perfect mixing of all constituents can be achieved when the peroxide and the soluble or insoluble catalyst are intimately mixed in advance in a dry condition, optionally compacted into moulds, and filled either into the reaction chamber 2 or into a separate receptacle 5 to be placed within the reaction chamber 2, and the ionic liquid is provided in a separate receptacle 6. Quick and perfect mixing can also be achieved when the catalyst is soluble in the ionic liquid, and is essentially dissolved therein. Placing the ionic liquid (or the ionic liquid and the catalyst) in a separate receptacle, although this is not absolutely necessary in a case where peroxide and catalyst (or the peroxide alone) are placed in a receptacle 5, constitutes an advantageous precautionary measure against accidental mixing of the constituents in case of receptacle 5 leakage or breakage. Care must be taken, when UHP and catalyst are mixed, because UHP is highly hygroscopic.

[0263] In a situation where oxygen shall be generated, receptacle 5, or receptacles 5 and 6, respectively, are destroyed by a breaking device 18. In FIG. 20, breaking device 18 has the form of a plate, however, means for destroying the receptacle(s) are not limited to plates, and other means are known to persons skilled in the art, for example firing pins or grids. Movement of plate 18 can be achieved by a spring 19 or another activation mechanism. During storage of the device for generating oxygen, spring 19 is under tension and holds plate 18 at a position distant from receptacles 5, 6. Once the tension is released by a suitable trigger mechanism (not shown), spring 19 moves plate 18 towards receptacles 5, 6, and plate 18 destroys receptacles 5, 6. Such a trigger may be, for example, pulling an oxygen mask towards a passenger in an airplane. Another exemplary trigger mechanism is an oxygen sensor sensing a low oxygen condition.

[0264] Receptacles 5, 6, and plate 18 are made from materials which guarantee that receptacles 5, 6 will be broken or ruptured when hit by plate 18. Exemplary materials are plastic foils or glass for receptacles 5, 6, and thicker plastic material or metal for plate 18.

[0265] Destruction of receptacles 5, 6 causes mixing of peroxide, ionic liquid, and catalyst, and initiates oxygen generation. In order to allow that the oxygen exits reaction chamber 2, reaction chamber 2 has an opening. In the illustrated embodiment, the opening is sealed with a gas permeable membrane 16. The opening may be at a different position than shown in FIG. 20, or there may be more than one opening. This applies analogously to all devices for generating oxygen of the invention.

[0266] In exemplary embodiments, the oxygen generated in the devices of this invention may be passed through a filter or other purification means as known in the art. The devices may be equipped with such means.

[0267] The oxygen generating reaction is an only slightly exothermic process, and proceeds at low temperature, i.e. below 150 C., or even below 120 C. or below 100 C. Therefore, reaction chamber 2 does not need to resist high temperatures, and may be made from lightweight, low melting materials such as plastic. In addition, any bulky insulation is not required. This is particularly advantageous in all cases where weight must be saved and/or space is limited, for example in the case of oxygen masks which shall be installed in an aircraft.

[0268] FIG. 21 illustrates an alternative embodiment of an exemplary device 1 for generating oxygen. In the exemplary embodiment of FIG. 21, the reaction chamber 2 has two compartments, a first compartment 3, and a second compartment 4, which are separated by a gastight membrane 17. The first compartment 3 contains one or more constituents of the composition for generating oxygen. Compartment 3 is equipped with a cutting device 20 having cutting edge 20, and the cutting device is arranged in a position that allows cutting edge 20 to cut through membrane 17 separating the first compartment 3 and the second compartment 4.

[0269] Compartments 3, 4 have openings sealed by membranes 15 and 16, respectively. Membranes 15, 16 are gas permeable, thus allowing the oxygen generated during the oxygen generating reaction to exit reaction chamber 2.

[0270] An activation mechanism 19, for example a spring, is provided for moving cutting device 20 towards membrane 17, and through membrane 17. Such a mechanism is described in DE 10 2009 041 065 A1. As explained in connection with FIG. 20, spring 19 is under tension during storage of device 1, and once the tension is released by a trigger mechanism (not shown), spring 19 moves receptacle 5 towards membrane 17, cutting edge 20 destroys membrane 17, and first compartment 3 and second compartment 4 are combined into one single reaction chamber 2.

[0271] In the exemplary embodiment illustrated in FIG. 20, a mixture of peroxide 7 and catalyst 9 is contained in the first compartment 3, and ionic liquid 8 is contained in second compartment 4. Upon destruction of membrane 17, the peroxide/catalyst formulation falls into the second compartment 4, and mixes with ionic liquid 8. The oxygen generated exits the reaction chamber 2 through membranes 15, 16.

[0272] Of course, it is also possible to place ionic liquid 8 into the first compartment 3 and the peroxide/catalyst formulation into the second compartment 4, or to use any other arrangement wherein at least one of the constituents is separated from the remaining constituents. For example, the catalyst may be provided in the form of a solution, i.e. dissolved in the ionic liquid.

[0273] As a material for the cutting device 20, any material may be used which may cut membrane 17, for example a metal sheet. The first compartment 3 and the second compartment 4 can be formed from the same materials as the single reaction chamber 2 illustrated in FIG. 20.

[0274] Another exemplary embodiment of an inventive device 1 for generating oxygen is illustrated in FIG. 22. In the embodiment of FIG. 22, the reaction chamber 2 is equipped with an injection device 21, for example a syringe or another dosing device.

[0275] Reaction chamber 2 and injection device 21 are connected, or constitute separate units which can be connected, to form one single unit. An opening, or several openings, in the wall of reaction chamber 2 allow that oxygen generated during the peroxide decomposition reaction exits reaction chamber 2. The openings are sealed in the embodiment shown by gas permeable membranes 16. In the exemplary embodiment illustrated in FIG. 22, the openings are provided at the junction of reaction chamber 2 and injection device 21.

[0276] The exemplary injection device of FIG. 22 comprises a slide bar 22, a spike 23, and an injection lance 24. The injection device is adapted for holding one or several constituents of the composition for generating oxygen, in the illustrated example the ionic liquid 8. Ionic liquid 8 is contained in a receptacle 5 made from a material which can be easily ruptured, for example a bag made from a plastic foil. A mixture of peroxide 7 and catalyst 9 is contained in reaction chamber 2. Alternatively, catalyst 9 may be contained in ionic liquid 8, dissolved or partly dissolved or dispersed therein, depending on the solubility of the inorganic or organic metal salt in the ionic liquid. In a device as illustrated in FIG. 22, any settlement of the catalyst within the ionic liquid during storage does not constitute a disadvantage because the catalyst will be re-dispersed during the injection step.

[0277] In the exemplary embodiments, slide bar 22 can be actuated in an analogous manner as the breaking device 18 in FIG. 20, and the cutting device 20 in FIG. 21. Once actuated, slide bar 22 pushes receptacle 5 towards spike 23, receptacle 5 is ruptured, and ionic liquid 8 is injected through injection lance 24 into reaction chamber 2. Preferably, injection lance 24 is provided with several holes (not shown) in order to provide uniform distribution of ionic liquid 8. Ionic liquid 8 soaks the mixture of peroxide 7 and catalyst 9, or alternatively the mixture or solution of ionic liquid 8 and catalyst 9 soaks peroxide 7, and the peroxide decomposition reaction starts, generating oxygen. The oxygen leaves reaction chamber 2 via membranes 16.

[0278] Analogously to the embodiments described above, the arrangement of peroxide 7, ionic liquid 8, and metal salt catalyst 9 may be different from the arrangement illustrated in FIG. 22. In particular, if not a liquid, but solid matter is contained in the injection device or dosing unit 21, no receptacle 5 is required, and means for destroying the receptacle, such as spike 23, and an injection lance are also not required.

[0279] FIG. 23 depicts an exemplary embodiment of the device 1 for generating oxygen which is similar to the embodiment depicted in FIG. 20. Different from the embodiment of FIG. 20, the device for generating oxygen of FIG. 23 is contained in a container 10 surrounding and protecting reaction chamber 2. In this case, the oxygen generated is not directly released into the environment, but rather enters into a gas space 11 between gas permeable membrane 16 and an upper wall of container 10. The oxygen exits gas space 11 via a gas outlet 12 which may be, for example, provided with a filter.

[0280] A device 1 as shown in FIG. 23 typically does not need any further thermal insulation. Rather, container 10 provides for sufficient insulation. If desired, a thin layer (for example, having a thickness of about 1 to 3 mm) of an insulating material may be placed between the outer wall of reaction chamber 2 and the inner wall of container 10. Such an insulating material may also serve the additional purpose of holding reaction chamber 2 tightly fixed in place within container 10. No insulating material should be provided between membrane 16 and the container wall opposite to membrane 16, i.e. in gas space 11.

[0281] Housing the reaction chamber within a container is advantageous both in devices for generating oxygen having only one reaction chamber, and in devices for generating oxygen having more than one reaction chamber, for example two reaction chambers or a plurality or multitude of reaction chambers 2. An embodiment having eight reaction chambers 2 is illustrated in FIG. 24.

[0282] In the exemplary device for generating oxygen illustrated in FIG. 24, reaction chambers 2 are shown schematically. Generally, the construction of reaction chambers 2 is not limited in any manner. For example, reaction chambers as illustrated in FIGS. 20 to 22 can be used. Furthermore, the arrangement of the reaction chambers is not limited to the arrangement shown in FIG. 24. Rather, the reaction chambers may be arranged within the container 10 in any appropriate manner.

[0283] Oxygen generation within reaction chambers 2 is initiated upon activation of reaction chambers 2. In the exemplary embodiment shown in FIG. 24, all reaction chambers 2 are activated simultaneously by a common activation mechanism 19, such as a spring, designed for pushing a plate 18 towards reaction chambers 2, as described in connection with FIG. 20. Alternatively, each reaction chamber may be activated individually, i.e. may have its own activation mechanism, or several reaction chambers may be arranged to groups, each group having its own activation mechanism. For example, in the embodiment of FIG. 24, the eight reaction chambers might be arranged into two groups of four chambers, each group having its own activation mechanism.

[0284] Container 10 provides a gas space 11 receiving oxygen from all reaction chambers 2, and the oxygen collected within gas space 11 exits gas space 11 via gas outlet 12. Alternatively, gas space 11 may be divided into a plurality of compartments. A separate compartment, having its own gas outlet, may be attributed to each reaction chamber 2, or one compartment may provide a common gas space for a group of reaction chambers 2. For example, container 10 may provide two gas spaces 11, and each gas space 11 may collect oxygen from four reaction chambers 2.

[0285] A device for generating oxygen having several reaction chambers 2 allows to extend oxygen generation over a long time span. As explained above, the reaction time of the peroxide decomposition reaction as well as the onset of the decomposition reaction can be manipulated by choosing appropriate metal salts as catalysts, by varying catalyst amounts and, in particular, by minimizing or maximizing the accessible surface area of the peroxide compound, for example by milling the peroxide compound to a fine powder or by pressing the peroxide compound into powder compacts. The higher the compacting pressure, the higher the density of the resulting powder compacts will be, thus minimizing the accessible surface area of the peroxide compound.

[0286] In the exemplary device illustrated in FIG. 24, each of the eight reaction chambers 2 may be charged with a different composition for generating oxygen. A first chamber may be charged, for example, with a composition comprising the peroxide compound in fine powdered form, and a high catalyst concentration. This chamber will generate oxygen immediately upon activation, and with a high reaction rate. Thus, breathable oxygen will be available immediately, but only for a short time span.

[0287] Three further reaction chambers 2 may be charged also with peroxide compound in fine powdered form, and with catalyst concentrations decreasing from chamber to chamber. In these reaction chambers oxygen generation will be slower, thus extending the time span wherein breathable oxygen is available.

[0288] The remaining four reaction chambers may be charged with peroxide compound which has been pressed into powder compacts, the compacting pressure increasing from chamber to chamber. In these chambers, the onset of the decomposition reaction will be delayed, the delay increasing with increasing compaction pressure. In another embodiment, the remaining four reaction chambers may be charged with peroxide compound both in powder and in compressed form, with an increasing ratio of powder compacts. This measure further extends the time span wherein breathable oxygen is available.

[0289] A similar result can be achieved with only one reaction chamber 2 by charging the single reaction chamber with different oxygen generating compositions, for example with different metal salts as catalyst and/or with oxygen sources in powder form and/or compressed with different compacting pressures.

[0290] Since the decomposition reactions are scalable to different reactor sizes, it is easily possible to charge an oxygen generating device according to this invention with an oxygen generating composition in a sufficient amount to provide for the desired oxygen flow rate. For emergency systems it is generally desired to produce at least 4 l oxygen per minute.

[0291] Of course, also different numbers of reaction chambers than those disclosed by way of example can be advantageously used.

[0292] The devices for generating oxygen of this invention may be designed as disposable devices (single use) filled with a composition for generating oxygen or compositions for generating oxygen, respectively, or as reusable devices which can be recharged after use with another composition for generating oxygen. Therefore, the constituents of the compositions for generating oxygen can be provided in the form of components suitable for recharging a device for generating oxygen, for example in cartridges.

[0293] In an exemplary embodiment, one component comprises a metal salt formulation and an ionic liquid formulation, and another component comprise an oxygen source formulation.

[0294] In an alternative exemplary embodiment, one component comprises an oxygen source formulation and an ionic liquid formulation, and another component comprises a metal salt formulation.

[0295] In another exemplary embodiment one component comprises an oxygen source formulation and a metal salt formulation, and another component comprises an ionic liquid formulation.

[0296] In a further exemplary embodiment, one component comprises an oxygen source formulation, another component comprises an ionic liquid formulation, and still another component comprises a metal salt formulation.

[0297] The term oxygen source formulation means that the oxygen source may be one single peroxide compound, but may be as well a combination of two or more peroxide compounds, and may optionally contain any additives not detrimentally interacting with the peroxide decomposition reaction.

[0298] The term ionic liquid formulation means that the ionic liquid may be one single ionic liquid, but may be as well a combination of two or more ionic liquids, and may optionally contain any additives not detrimentally interacting with the peroxide decomposition reaction. The ionic liquids themselves shall not react with any of the constituents of the compositions for generating oxygen, or with any intermediate products generated during the decomposition reaction.

[0299] The term metal salt formulation means that the catalyst may be one single metal salt, but may be as well a combination of two or more metal salts, and may optionally contain any additives not detrimentally interacting with the peroxide decomposition reaction. The metal salts are salts having organic and/or inorganic anions, and are soluble, partly soluble, or insoluble in the ionic liquid (formulation).

[0300] The devices for generating oxygen according to the present invention are not sensitive to interruptions of the oxygen production process, in contrast to chlorate candles which can be easily destabilized, for example by shaking. Shaking a device for generating oxygen according to the present invention enhances mixing of the constituents of the oxygen generating composition and, therefore, promotes the oxygen generation reaction.

[0301] In embodiments wherein the metals salt is provided in a dissolved state, i.e. dissolved in the ionic liquid, there is the additional advantage that even during long term storage no sedimentation of the metal salt can be take place. The catalyst remains homogenously distributed in the ionic liquid, and contacts the peroxide compound at the very moment when the ionic liquid contacts the peroxide compound.

[0302] The inventive devices can be construed in such a manner that the orientation of the inventive devices for generating oxygen in the gravity field of the earth is arbitrary. To this end, several oxygen outlets (sealed by gas permeable membranes or other structures allowing passage of oxygen, while blocking passage of non gaseous substances) must be provided in the walls of reaction chamber(s) 2, and the openings must be arranged in such a manner, that there is always an opening which is not covered by ionic liquid, irrespective of the orientation of the device.

[0303] The oxygen produced according to this invention is pure and at a low temperature and, therefore, ideal for applications such as self-rescuers. The use for technical purposes such as in portable welding devices and control nozzles, however, is also contemplated.