OXYGEN GENERATOR AND METHOD FOR STARTING OR ACCELERATING THE OXYGEN PRODUCTION OF AN OXYGEN GENERATING COMPOSITION

Abstract

An oxygen generator has a composition for generating oxygen and a basic compound. The composition for generating oxygen includes an oxygen source, an ionic liquid, a metal salt, and an optional basic compound. The oxygen source is a peroxide compound, the ionic liquid is in the liquid state at least in a temperature range from −10° C. to +50° C., the metal salt has one single metal or two or more different metals, and an organic and/or an inorganic anion. There is also described a method for starting or accelerating the oxygen production of an oxygen generating composition, and a device for generating oxygen in a controlled manner.

Claims

1. An oxygen generator, comprising: a composition for generating oxygen including an oxygen source, an ionic liquid, and a metal salt, and a basic compound for starting or accelerating oxygen production; said oxygen source comprising a peroxide compound; said ionic liquid being in the liquid state at least in a temperature range from −10° C. to +50° C.; and said metal salt having one single metal or two or more different metals, and an organic and/or an inorganic anion.

2. The oxygen generator according to claim 1, wherein said oxygen source is selected from the group consisting of alkali metal percarbonates, alkali metal perborates, urea hydrogen peroxide, and mixtures thereof.

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

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

5. The oxygen generator according to claim 1, further comprising an acidic compound for decelerating or stopping oxygen production.

6. The oxygen generator according to claim 5, wherein said acidic compound is selected from the group consisting of inorganic acids, organic acids, acidic salts and ionic liquids having acidic functionality.

7. The oxygen generator according to claim 6, wherein said acidic compound is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, succinic acid, citric acid, benzoic acid, sodium hydrogen sulfate, monopotassium phosphate, 1-ethyl-3-methylimidazolium hydrogen sulfate, trimethylammonium propane-sulfonic acid hydrogen sulfate, 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate, and diethylmethylammonium methanesulfonate.

8. The oxygen generator according to claim 1, wherein said basic compound is selected from the group consisting of hydroxides, basic oxides, basic salts and ionic liquids having basic properties.

9. The oxygen generator according to claim 1, wherein said basic compound is selected from the group consisting of sodium hydroxide, potassium hydroxide, potassium phosphate, sodium acetate, sodium percarbonate, potassium carbonate, calcium hydroxide, calcium oxide, 1-ethyl-3-methylimidazolium acetate, tetrabutylammonium arginine, and tetraethylammonium but-3-enoate.

10. The oxygen generator according to claim 1, wherein a pK.sub.b-value of said basic compound is below 10, and/or wherein the oxygen generator further comprises an amount of said basic compound sufficient for allowing complete oxidation of said metal ion of said metal salt by at least one oxidation state.

11. The oxygen generator according to claim 10, wherein the pK.sub.b-value of said basic compound is below 9.5 and said basic compound is present in an amount sufficient for allowing the complete oxidation of said metal ion by two oxidation states.

12. The oxygen generator according to claim 5, wherein said acidic compound is provided in solid form or in a solution or dispersion or as a pure liquid substance, and/or wherein said basic compound is provided in solid form or in a solution or dispersion or as a pure liquid substance.

13. The oxygen generator according to claim 12, wherein said acidic compound is a tuner compact.

14. A composition for generating oxygen, comprising: an oxygen source, an ionic liquid, a metal salt, and a basic compound; or if the ionic liquid is a basic ionic liquid or the oxygen source is basic, an oxygen source, an ionic liquid and a metal salt; wherein: the oxygen source comprises a peroxide compound; the ionic liquid is in a liquid state in a temperature range from −10° C. to +50° C.; and the metal salt comprises one single metal or two or more different metals, and an organic and/or an inorganic anion.

15. A method of starting or accelerating an oxygen production of an oxygen generating composition, the method comprising: providing an oxygen source comprising a peroxide compound; providing an ionic liquid, which in a liquid state in a temperature range from −10° C. to +50° C.; providing a metal salt, the metal salt having one single metal or two or more different metals, and an organic and/or an inorganic anion; contacting the oxygen source, the ionic liquid and the metal salt; and starting or accelerating the oxygen production by adding a basic compound to the oxygen source, the ionic liquid, and/or the metal salt.

16. The method according to claim 15, which comprises decelerating or stopping the oxygen production after a desired time interval by adding an acidic compound, once or multiple times.

17. The method according to claim 15, wherein a pK.sub.b-value of the basic compound and/or a further basic compound is below 10.

18. The method according to claim 15, which comprises setting an amount of the basic compound to be sufficient for allowing complete oxidation of the metal ion of the metal salt by at least one oxidation state.

19. The method according to claim 18, wherein a pK.sub.b-value of the basic compound and/or a further basic compound is below 9.5 and an amount of the basic compound is sufficient to completely oxidize the metal ion of the metal salt by at least two oxidation states.

20. A device for generating oxygen in a controlled manner, the device comprising: a reaction chamber for housing a composition for generating oxygen, the composition being a combination of constituents including of an oxygen source, an ionic liquid, and a metal salt; at least one dosing device housing a basic compound and being configured for introducing the basic compound into said reaction chamber, and, optionally, at least one dosing device housing an acidic compound and being configured for introducing the acidic compound into said reaction chamber; a separator device for maintaining at least one of the oxygen source, the ionic liquid, and the metal salt physically separated from remaining constituents of the composition for generating oxygen; a device for establishing physical contact between the oxygen source, the ionic liquid, and the metal salt; and a device for allowing oxygen to exit the reaction chamber; or a reaction chamber housing a composition for generating oxygen, the composition comprising a combination of constituents including of an oxygen source, an ionic liquid, and a metal salt; a device for allowing oxygen to exit the reaction chamber; at least one dosing device housing a basic compound and being configured for introducing the basic compound into said reaction chamber, and, optionally, at least one dosing device housing an acidic compound and being configured for introducing the acidic compound into said reaction chamber; wherein: the metal salt comprises a single metal or two or more different metals, and an organic and/or an inorganic anion; the oxygen source comprises a peroxide compound, the ionic liquid is in the liquid state at least in the temperature range from −10° C. to +50° C.; and a control device for controlling an oxygen production rate by selectively adding the basic compound or, optionally, the acidic compound to the composition for generating oxygen.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0137] FIGS. 1-6 are graphs illustrating start of decomposition of UHP (urea hydrogen peroxide) by addition of basic compounds which decomposition is catalyzed by dissolved metal salts as catalysts,

[0138] FIG. 7 is a graph summarizing data deducted from the results given in FIGS. 1 to 6 showing the amount of basic composition required for starting reaction in dependence from strength of the basic compound,

[0139] FIG. 8 is a graph summarizing data deducted from further experiments for determination of the amount of basic composition required for starting reaction in dependence from strength of the basic compound,

[0140] FIGS. 9 and 10 are graphs illustrating acceleration of decomposition of UHP, which decomposition is catalyzed by dissolved metal salts and started by addition of a basic compound and which acceleration is caused by further basic compound,

[0141] FIG. 11 is a sectional view of an embodiment of a device for generating oxygen according to this invention, and

[0142] FIG. 12 is a sectional view of another embodiment of a device for generating oxygen according to this invention.

DETAILED DESCRIPTION OF THE INVENTION

[0143] In all graphs illustrating oxygen release, oxygen flow rate and volume are plotted against runtime, wherein runtime is the time which starts running at the time point of contacting the oxygen source, the ionic liquid, the metal salt with a basic compound. “Volume” is the oxygen volume released in total. Oxygen flow rate (I/h) and volume released (I) by each decomposition reaction where measured with a drum gas meter in each of the experiments of examples 1 to 3, throughout the experiments.

Example 1

[0144] In example 1 different basic compounds were added to oxygen generating compositions comprising ionic liquid, a Mn.sup.2+-salt and UHP for evaluating conditions required for starting oxygen generation. In general, 100 g urea hydrogen peroxide (UHP) were mixed with 1 mol % MnCl.sub.2 with respect to the amount of UHP which MnCl.sub.2 was dissolved in 30 g of an ionic liquid which was [EMIM][EtSO.sub.4] or [MMIM][PO.sub.4Me.sub.2]. The resulting mixture generated no oxygen. After 10 minutes given for equilibration a solution of a basic compound in 10 g [EMIM][EtSO.sub.4] or [MMIM][PO.sub.4Me.sub.2] was added to the mixture. The kind of basic compound and the amount of basic compound were varied in these experiments. Volume of the oxygen produced in the reactions was measured by means of the gas meter.

[0145] Since the oxygen generating mixture needed some time for starting in some cases released volume of oxygen was only assessed 50 minutes after addition of the basic compound. The reaction was considered as started when more than 0.5 g UHP were degraded after 50 minutes. The amount required for starting the reaction was determined from the experimental data by linear approximation.

[0146] In experiments 1 to 17 the types and amounts of compounds given in below tables have been used.

TABLE-US-00001 TABLE 1 Catalyst Peroxide IL Base n(Base)/ n(Base)/ Experiment (Mass) (Mass) (Mass) (Mass) n(IL) n(MnCl.sub.2) 1 MnCl.sub.2 UHP [MMIM][PO.sub.4Me.sub.2] TRIS (325.0 mg) in 10 g 0.0149 0.252 (1.34 g) (100 g) (30 g) [MMIM][PO.sub.4Me.sub.2] 2 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] TRIS (81.3 mg) in 10 g 0.00390 0.0630 (1.34 g) (100 g) (30 g) [MMIM][PO.sub.4Me.sub.2] 3 MnCl.sub.2 UHP [MMIM][PO.sub.4Me.sub.2] TRIS (40.6 mg) in 10 g 0.00190 0.0315 (1.34 g) (100 g) (30 g) [MMIM][PO.sub.4Me.sub.2]
Results are given in FIG. 1.

TABLE-US-00002 TABLE 2 Catalyst Peroxide IL Base n(Base)/ n(Base)/n Experiment (Mass) (Mass) (Mass) (Mass) n(IL) (MnCl.sub.2) 4 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] Imidazole (340 mg) in 10 g 0.0295 0.469 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4] 5 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] Imidazole (170 mg) in 10 g 0.0148 0.234 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4] 6 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] Imidazole (85 mg) in 10 g 0.00738 0.117 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4]
Results are given in FIG. 2.

TABLE-US-00003 TABLE 3 Catalyst Peroxide IL Base n(Base)/ n(Base)/n Experiment (Mass) (Mass) (Mass) (Mass) n(IL) (MnCl.sub.2) 7 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] 2-Methylpyridine (3 g) 0.190 3.02 (1.34 g) (100 g) (30 g) in 10 g [EMIM][EtSO.sub.4] 8 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] 2-Methylpyridine (0.6 g) 0.0381 0.605 (1.34 g) (100 g) (30 g) in 10 g [EMIM][EtSO.sub.4] 9 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] 2-Methylpyridine (0.3 g) 0.0190 0.302 (1.34 g) (100 g) (30 g) in 10 g [EMIM][EtSO.sub.4] 10 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] 2-Methylpyridine (0.1 g) 0.00634 0.101 (1.34 g) (100 g) (30 g) in 10 g [EMIM][EtSO.sub.4]
Results are given in FIG. 3.

TABLE-US-00004 TABLE 4 Catalyst Peroxide IL Base n(Base)/ n(Base)/n Experiment (Mass) (Mass) (Mass) (Mass) n(IL) (MnCl.sub.2) 11 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] p-Toluidine (4 g) in 10 g 0.221 3.51 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4] 12 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] p-Toluidine (2 g) in 10 g 0.110 1.75 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4] 13 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] p-Toluidine (1 g) in 10 g 0.0551 0.876 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4]
Results are given in FIG. 4.

TABLE-US-00005 TABLE 5 Catalyst Peroxide IL Base n(Base)/ n(Base)/n Experiment (Mass) (Mass) (Mass) (Mass) n(IL) (MnCl.sub.2) 14 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] Aniline (5 g) in 10 g 0.317 5.04 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4] 15 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] Aniline (2 g) in 10 g 0.127 2.02 (1.34 g) (100 g) (30 g) [EMIM][EtSO.sub.4]
Results are given in FIG. 5.

TABLE-US-00006 TABLE 6 Catalyst Peroxide IL Base n(Base)/n n(Base)/n Experiment (Mass) (Mass) (Mass) (Mass) (IL) (MnCl.sub.2) 16 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] 2,6-Dimethylaniline (8 g) 0.390 6.20 (1.34 g) (100 g) (30 g) in 10 g [EMIM][EtSO.sub.4] 17 MnCl.sub.2 UHP [EMIM][EtSO.sub.4] 2,6-Dimethylaniline (5 g) 0.244 3.87 (1.34 g) (100 g) (30 g) in 10 g [EMIM][EtSO.sub.4]
Results are given in FIG. 6.

[0147] From the results of experiments 1 to 17 a relation between the strength of the added basic compound and the amount required for starting oxygen production by peroxide decomposition according to the above definition can be seen. The stronger the basic compound, e.g. the lower the pK.sub.b-value, the smaller is the amount of the basic composition required for starting the reaction. Basic compounds having a pK.sub.b-value above 10 are only able to accelerate oxygen production but not to start oxygen production. The results are summarized in FIG. 7 and below Table 7.

TABLE-US-00007 TABLE 7 pK.sub.b- n(Base) n(Base)/ n(Base)/ Base Value [mmol] n(IL) n(MnCl.sub.2) TRIS 5.94 0.250 1.38E−3 0.0233 Imidazole 6.95 2.07 12.6E−3 0.194 2-Methylpyridine 8.06 1.51 9.25E−3 0.147 p-Toluidine 8.92 15.8 0.0932 1.48 Aniline 9.13 19.4 0.115 1.83 2,6-Dimethylaniline 10.05 66.0 0.390 6.20 Dimethylphosphate 12.71 180 1.00 16.9

[0148] FIG. 7 shows as a function of the strength of the basic compound how many equivalents of the basic compound in relation to MnCl.sub.2 are required for starting peroxide decomposition. Filled squares symbolize start of peroxide decomposition by addition of the given amount of basic compound. Crosses indicate that the amount of the added basic compound did not result in a start of the reaction. The dotted curve is a calculated curve fitted to the calculated values.

Example 2

[0149] In example 2 another approach for determining the influence of the strength of a basic compound on peroxide decomposition has been used. In general, 20 g UHP were given in a flask. In 10 g of ionic liquid [MMIM][PO.sub.4Me.sub.2] 1 mol % MnCl.sub.2 with respect to the amount UHP and a defined amount of a basic compound were dissolved. This solution was then given into the flask containing the UHP. Kind and amount of the basic compound dissolved in the ionic liquid were varied. 3 days after start of reaction a sodium hydroxide solution was added to the reaction mixture. If not-degraded peroxide was still present in the flask it was then degraded. The volume of produced oxygen was measured by means of the gas meter. The reaction was considered as started if no peroxide could be detected in the flask 3 days after start of the reaction. The amount of basic compound required for start of the reaction has been determined from experimental data by linear approximation.

[0150] FIG. 8 shows the amount of basic compound required for start of the reaction according to the above definition in dependence from the strength of the basic compound. Filled circles symbolize the amount of basic compound in relation to the amount of ionic liquid sufficient for start of the oxygen generation. The empty circle refers to a start of peroxide decomposition, wherein the amount of basic compound is given for the first pK.sub.b-value of the dibasic disodium malonate.

[0151] The results show the relation between the pK.sub.b-value of the basic compound and the amount of this basic compound required for start of the reaction. The results confirm the results obtained with experiment 1.

Example 3

[0152] For determining the effect of addition of a basic compound to a running oxygen production 2 g Sodium acetate and 1.57 g Mn(OAc).sub.2*4H.sub.2O were dissolved in 30 g of ionic liquid [MMIM][PO.sub.4Me.sub.2] and given to 100 g UHP in a flask. This resulted in peroxide decomposition and release of oxygen within a short time. Oxygen production rate rose up to 25 I/h and then decreased continuously. 16:30 minutes after start of the reaction a solution containing 16.5 mmol of a basic compound in 10 g of ionic liquid [MMIM][PO.sub.4Me.sub.2] were added. Type and amount of the different compounds of the compositions are given in below table 8.

TABLE-US-00008 TABLE 8 Catalyst Peroxide 1.sup.st Base 2.sup.nd Base strength of Base Experiment (Mass) (Mass) (Mass) (Mass) (pK.sub.b) 18 Mn(OAc).sub.2*4 UHP [MMIM][PO.sub.4Me.sub.2] TRIS (2.00 g) 5.94 H.sub.2O (100 g) (30 g) + in 10 g (1.57 g) Sodium acetate (2 g) [MMIM][PO.sub.4Me.sub.2] 19 Mn(OAc).sub.2*4 UHP [MMIM][PO.sub.4Me.sub.2] Imidazole (1.12 g) 6.95 H.sub.2O (100 g) (30 g) + in 10 g (1.57 g) Sodium acetate (2 g) [MMIM][PO.sub.4Me.sub.2] 20 Mn(OAc).sub.2*4 UHP [MMIM][PO.sub.4Me.sub.2] Pyridine (1.30 g) 8.94 H.sub.2O (100 g) (30 g) + in 10 g (1.57 g) Sodium acetate (2 g) [MMIM][PO.sub.4Me.sub.2] 21 Mn(OAc).sub.2*4 UHP [MMIM][PO.sub.4Me.sub.2] Sodium acetate 9.25 H.sub.2O (100 g) (30 g) + (1.35 g) (1.57 g) Sodium acetate (2 g) in 10 g [MMIM][PO.sub.4Me.sub.2]

[0153] The volume of oxygen produced is shown in FIG. 9 and the flow rate is shown in FIG. 10. The data show that basic compounds having a bigger strength of base, i.e. a smaller pK.sub.b-value, result in a bigger acceleration of peroxide decomposition.

[0154] FIG. 11 illustrates an exemplary device 1 for generating oxygen in a controlled manner, the device 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 can be enclosed in a receptacle in order to avoid contact with the remaining constituents of the composition contained in the reaction chamber 2. The device is particularly suitable for use with neutral and basic ionic liquids. In the embodiment shown in FIG. 11, 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 or metal oxide compounds) in the ionic liquid. This 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.

[0155] 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 molds, 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.

[0156] 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. 11, 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.

[0157] 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.

[0158] 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. 11, or there may be more than one opening.

[0159] In exemplary embodiments, the oxygen generated in the device described herein may be passed through a filter or other purification means as known in the art. The device may be equipped with such means.

[0160] 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 plastics. 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.

[0161] The exemplary device illustrated in FIG. 11 is equipped with two injection devices 11, 11′, for examples syringes or other dosing devices. Openings 17, 17′ fluidly connect the interior spaces of reaction chamber 2 and of injection devices 11, 11′ respectively.

[0162] The injection device 11 comprises a receptacle 12, a slide bar 13 and a spike 14. The injection device 11′ comprises a receptacle 12′, a slide bar 13′ and a spike 14′. Spikes 14, 14′ are held in place by fixtures 15, 15′. Receptacles 12, 12′ are made from a material which can easily be ruptured, for example bags made from plastic foils. Receptacle 12 contains an acidic compound and receptacle 12′ contains a basic compound.

[0163] In the exemplary embodiment illustrated in FIG. 11, slide bars 13, 13′ can be actuated in an analogous manner as the braking device 18. Once actuated, slide bar 13 pushes receptacle 12 towards spike 14, receptacle 12 is ruptured and acid is injected through opening 17 into reaction chamber 2. Similarly, once actuated, slide bar 13′ pushes receptacle 12′ towards spike 14′, receptacle 12′ is ruptured and base is injected through opening 17′ into reaction chamber 2.

[0164] Actuation of braking device 18 starts the peroxide decomposition reaction in reaction chamber 2. Without interference, the decomposition reaction proceeds until all peroxide compound has been decomposed. The device illustrated in FIG. 11 allows a user to stop the peroxide decomposition reaction by actuating slide bar 13, and to save the peroxide not yet decomposed for later use. Whenever oxygen is needed again, the user may actuate slide bar 13′, thus starting the peroxide decomposition reaction again.

[0165] The device illustrated in FIG. 11 has only one injection device 11 containing an acidic compound, and one injection device 11′ containing a basic compound. Such a device allows to stop and to restart the peroxide composition reaction only once. Providing reaction chamber 2 with several injection devices containing an acid, and with several injection devices containing a base allows to stop and to restart the peroxide decomposition several times. For example, a device 1 for generating oxygen having three injection devices containing acidic compounds and having three injection devices containing basic compounds, allows a user to interrupt and to restart the oxygen production three times, or at least until all of the oxygen source has been decomposed.

[0166] If desired, a device as illustrated in FIG. 11 can be also used for reducing or increasing the oxygen flow rate by injecting an acidic compound or a basic compound, respectively into reaction chamber 2, for example when leveling out increasing or decreasing or fluctuating oxygen flow rates shall be achieved.

[0167] It is also possible to provide only injection devices filled with acid, or only injection devices filled with base. In such a case, oxygen generating device 1 will only allow to reduce the oxygen flow rate, or to increase the oxygen flow rate, respectively.

[0168] An alternative exemplary device for generating oxygen in a controlled manner is illustrated in FIG. 12. In FIG. 12 the same reference numerals as in FIG. 11 are used for designating components which correspond to components already illustrated in FIG. 11.

[0169] The device illustrated in FIG. 12 is suitable for use with acidic ionic liquids. In the illustrated embodiment, reaction chamber 2 contains a mixture of acidic ionic liquid 8, oxygen source 7 and decomposition catalyst 9, for example pellets comprising a peroxide/catalyst mixture dispersed within the ionic liquid. Of course, the acidic ionic liquid, the oxygen source and the catalyst may be provided in any different manner, for example in the form of a dispersion of oxygen source powder in a solution of the catalyst within the ionic liquid.

[0170] The exemplary device illustrated in FIG. 12 is equipped with two injection devices 11, 11′, which are identical to the injection devices 11, 11′ of the device illustrated in FIG. 11. Injection device 11 contains an acidic compound, and injection device 11′ contains a basic compound. Injection device 11 may be omitted. An oxygen generating device 1 having only injection device 11′ allows to start the peroxide decomposition reaction by destroying receptacle 12′ and injecting the basic compound through opening 17′ into reaction chamber 2. The peroxide decomposition reaction will then proceed until all peroxide compound has been decomposed, and the oxygen generated by the composition reaction will leave reaction chamber 2 through gas permeable membrane 16.

[0171] A device for generating oxygen in a controlled manner needs at least one further injection device, for example injection device 11 containing an acidic compound, as illustrated in FIG. 12. Injecting the acidic compound contained in injection device 11 into reaction chamber 2 allows to decelerate the peroxide decomposition reaction and to reduce a too high oxygen flow rate.

[0172] In alternative embodiments, the oxygen generating device illustrated in FIG. 12 may be provided with one or more additional injection devices containing basic compounds and/or with one or more additional injection devices containing acidic compounds. Such additional injection devices allow to increase or decrease the oxygen production rate, respectively, or to stop and restart the oxygen production several times.

[0173] The oxygen produced according to this invention is pure and at a low temperature and, therefore, ideal for applications in airplanes, in self-rescuers and in rebreathers. However, the use for technical purposes such as in portable welding devices in mining and submarine applications, and in spaceflight, e.g. in control nozzles is also contemplated.

[0174] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.