MXPA96003258A - Combination of gas adsorbing materials and device to contain my mis - Google Patents

Abstract

A combination of gas adsorbent materials particularly suitable for maintaining the vacuum in devices that can not be heated to temperatures greater than about 200 ° C comprises: a) a MO / Pd mixture between a metal transition oxide MO chosen from cobalt oxide, oxide of copper or its combinations, and metallic palladium, where the latter is present up to about 2% by weight, and b) a moisture adsorbing material, in particular applications, it is possible to add to this combination also a barium-based alloy based on lithium, preferably BaLi4; gas adsorbing devices are also described to contain said combination

Description

COMBINATION OF GAS ADSORBING MATERIALS AND DEVICE TO CONTAIN THEMSELVES FIELD OF THE INVENTION 5 The present invention relates to a new combination of gas adsorbing materials and gas adsorbing devices containing them. In particular, the present invention relates to a gas adsorber combination suitable for maintenance in devices that can not be heated to temperatures greater than about 200 ° C. Gas adsorbing materials have been found that are practically necessary in all applications related to industry and commerce in which a vacuum is required.

BACKGROUND OF THE INVENTION 0 Until a few years ago, in all the devices that require vacuum for their operation, the walls designed to confine the vacuum are made of metal or glass. The volumes evacuated by metal walls are present, e.g., in "thermos" or "Deward flasks", in thermally insulated tubes for the transport of biogenic fluids, or in scientific applications, such as particle accelerators. Instead, evacuated volumes defined by glass walls present, e.g., in cathode ray tubes for television or computer screens and in lamps. In these applications, the gas adsorbing material is inactivated into the device before they are subsequently activated, when the device is sealed, by means of heating from the outside, such as with radio frequency waves. The activated adsorber of gases adsorbs the last traces of gases still present in the device and realizes the absorption of those gases that, through various mechanisms, enter the volume evacuated during the life of the device itself. The minimum temperatures required by conventional adsorber gases for activation are of the order of 350 ° - 400 ° C and in some cases even temperatures up to 900 ° C can be reached. Gas adsorbing materials of this type are, for example, alloys based on zirconium or titanium. However, in more recent years the use of vacuum in the industrial field has been removed to evacuated devices made at least in part from plastic materials, which can not be heated to temperatures greater than about 200 ° C; This is for example the case of thermally insulated sleeves under vacuum, where the plastic materials can be used to form the walls of the filling materials or both. Filling materials (hereinafter defined as "fillers") are usually in the form of fibers, powders or foams and are used on shirts to maintain the shape thereof. A typical example of such shirts are evacuated panels, mainly used in the production of refrigerators. The wrapping of these panels is usually made of laminated plastic-metal films thermally sealed at their edges through a plastic to plastic contact, metal-to-metal sealing is avoided to break the thermal bridge between the two faces of the panel. Plastic materials can not be heated to temperatures higher than approximately 200 ° C to prevent the chemical and metallic stability of them from being annulled. Therefore, conventional gas adsorbing materials are unsuitable for this type of use. This has created the demand for the availability of gas adsorbing materials with a low activation temperature or, what is better, they do not require thermal activation. International patent application UO 94/18876 describes the use in combination of an oxide of a noble metal, in particular palladium oxide (PdO) and a moisture-adsorbing material, such as vario oxide (BaO), for maintenance of vacuum in shirts evacuated from flasks of Dewar, thermos, etc. However, the oxide of p > Aladio, through a reaction with hydrogen, is converted to metallic Pd in a finely pulverized form, which has pyrophobic properties. Consequently, the use of this combination of materials is not recommended for safety reasons. The patents of E.U.A. Nos. 5,312,606 and 5,312,607 in the name of the applicant describe a family of alloys based on barium and lithium with other elements added such as aluminum or alkaline earth elements; These alloys are the only known gas adsorbing materials able to adsorb virtually all gases at room temperature without requiring thermal activation. Specific applications of these materials are described, e.g., in the U.S. patent. 5,408,832 in and in the patent application 'International UO 96/1966. In particular, the preferred alloy is the BaLi alloy «. To ensure the nitrogen adsorption capacity of this alloy, which could be depleted by the adsorption of water vapor, U.S. Patent No. 5,408,832 describes the use of BaLi "in combination with a moisture adsorbing material, such as oxide. barium. This combination of materials shows very good performance with respect to the removal of O2, N2 and H2O, thus eliminating the main atmospheric gases of the gaseous environment inside the shirts. However, the gaseous composition within these liners depends mainly on the degassing of the materials forming said liners, in particular the fillers which are generally in the form of powder, foam or wool, and consequently they are provided with a large specific surface area. The main gases that are present in the shirts made of plastic material are CO and CO2 in the case of polymeric filler and H2 in the case of eg glass wool. The charge of these gases can be important, mainly provided that in the shirt manufacturing process there are heating steps; for example, there is the case of the manufacture of refrigerators, where the vacuum insulation panels are fixed to the walls of the apparatuses by means of polymeric foams, generally polyurethanes obtained by reacting suitable chemical compounds in an in situ foaming process. , during which temperatures close to 100 ° C can be reached for a few minutes. Another important contribution to the gas atmosphere within the panels is from organic compounds, i.e., hydrocarbons or substituted hydrocarbons in which hydrogen can be partially or completely replaced by halogen atoms. Compounds in which halogen atoms completely replace hydrogen are known as CFCs and have been used for decades in the production of thermal insulation panels for refrigerators. It has been recognized that these gases are the ones that cause the depletion effect of the ozone layer, and their production and use have been discontinued. However, recirculation of old panels containing CFC is being studied through its reduction to powders of the polymeric foams they contain and the use of these powders in the production of new panels. Small amounts of CFCs could enter thermal insulation panels freshly produced in this way. Halogen-substituted hydrocarbons, generally known as HCFCs and hydrocarbons, have replaced CFC in this field, and are used as foaming agents both in the production of panels and in the step of fixing the panels to the walls of the refrigerator by means of foams very similar to those that are inside the panels. The most important gases in this application are cyclopentane, C5 Hio, V 1.1, -chloro-l-fluoroethane, Cl-2 FC-CH-3, the latter known in the art as 141-b. These last gases can enter the panels through the edges, in the area where the laminated plastic-metal films of which the envelope is made are sealed through a thermal seal from plastic to plastic: this results in an increase in the pressure inside the panel and the worsening of its thermal insulation properties. The BaO / BaLi * combination described above can adsorb CO, CO2 and particularly H2, but at a relatively low speed; however, it is known that the gas adsorbing materials of the prior art are capable of effectively adsorbing organic compounds. ThusAnother object of the present invention is to provide a combination of gauze adsorbing materials of improved absorption properties for CO2 and H2 and capable of adsorbing organic compounds, which do not require thermal activation and therefore are compatible with devices in which less one component can not be heated to temperatures greater than about 200 ° C. Another object of the invention is to provide a device for using that combination of gas adsorbing materials. In accordance with the present invention, these and other objects are obtained with a combination of gas adsorbing materials composed of: a mixture of a transition metal oxide selected from cobalt oxide, copper oxide or. its combinations and metallic palladium containing up to about 2% by weight of palladium metal; a moisture adsorbing material having a vapor pressure of HO2 less than 1 Pa at room temperature. Although there are several cobalt oxides, in accordance with the oxidation number of the metal, the only one that is useful for the invention is the oxide having the empirical form C03O4, where the cobalt is present at the same time under the oxidation state II and the oxidation state III; in the following specification and in the claims with cobalt oxide will be understood the compound as co-defined herein. Similarly, with copper oxide in the following of the specification and claims the compound of CUO will be understood, wherein the copper is present under the oxidation state II. In addition, the abbreviation MO will be used in general to mark in general one of the two oxides of transition metals with a combination thereof and the abbreviation MO / Pd to indicate the mixture between MO and metallic palladium. The properties of these oxides were already known, for example in an article by Belousov et al., Ukrainskij Chimiceskij Zurnal, 1986, 52, No. 8, but only for the absorption of hydrogen. During the preparation of the transition metal oxide, a metal palladium precursor is added to the latter in an amount such that it has a final mixture containing about 2% by weight of the MO / Pd mixture. Palladium can be co-precipitated with the transition metal oxide by its introduction into the same stock solution, in the form of a soluble salt, e.g., PdCl2; since an alternative palladium can be deposited from a solution on grains of transition metal oxides being previously formed. The transition metal oxide is used in powder form with a particle size less than 500u, preferably a compound between 1 and 200 u. The moisture adsorbing material can be chosen among the chemical moisture adsorbers; These materials, known in the art, fix the water in an irreversible manner through a chemical reaction. Suitable for this application are chemical dryers having a vapor pressure of HO2 less than one Pa at room temperature, as described in the U.S. patent. No. 5,408,832 for the applicant. For example, the calcium, strontium, barium and phosphorus oxides of their combinations are considered suitable for the objects of the invention. The use of barium oxide or calcium oxide is particularly preferred. The moisture adsorbing material is preferably used in the form of a powder having a particle size of between about 50 and 500 microns. With a larger particle size, an excessive reduction of the surface area of the powder is expressed, whereas with a smaller particle size there is a risk that, due to the absorption of moisture, the powders become excessively compacted, thus making it difficult the passage of gases through the powders themselves. To overcome the problem of wet powder compaction, it is also possible to add to the moisture adsorbing material powder of an inert material, such as alumina, described in the aforementioned International patent application IO 96/01966. The weight ratio between the materials of the combination of the invention can vary within wide limits, depending also on the type of use that is foreseen and in particular of the mixture of gases to be adsorbed. However, in general, the weight ratio between the MO / Pd mixture and the moisture adsorbing material can vary between 5: 1 and 1:20, and preferably between 1: 1 and 1: 5. If in a particular application it is foreseen that the vacuum initially present in the jacket can be subject to degradation also due to the contribution of atmospheric gases such co or O2 and 2, to the combination MO / Pd with moisture adsorber as described above, it is also possible to add a barium-based and lithium-based alloy between those described in US Pat., 312,606 and 5,312,607 mentioned above, to which reference will be made for details about the preparation and properties of these alloys. The barium-based and lithium-based alloy is preferably used in powder form with a particle size of less than about 500 microns, and preferably less than about 150 microns, to increase the surface area. The powder may also be slightly compressed as indicated in the abovementioned WO 96/01966 application. The preferred alloy is that of BaLi "composition, mentioned above. The barium and lithium alloys and the cobalt or copper oxides have a mutual reaction and therefore should be kept separate so as not to cause alterations in the performance of the gas adsorber combination. The weight ratios between the barium-based and lithium-based alloy and the other components of the combination according to the invention can vary within wide ranges. The weight ratio between the MO / Pd mixture and the barium-based and lithium-based alloy can generally vary between 10: 1 and 1: 5 and preferably between 5: 1 and 1:12. The weight ratio between the moisture adsorbing material and the barium-based and lithium-based alloy can vary between about 50: 1 and 1: 5 preferably between 20: 1 and 1: 1.

DESCRIPTION OF THE DRAWINGS In a second aspect, the invention relates to gas adsorbing devices that contain a combination of materials as described heretofore. In the following description reference is made to the drawings in which: Figure 1 shows a possible embodiment of a gas adsorber device of the invention; the figure shows a possible alternative embodiment of a gas adsorber device of the invention. Figure 2 shows a possible mode of the gas adsorber device of the invention in the case of a mixture with three components MO / Pd, moisture adsorbing material and alloy based on barium and based on lithium; Figure 3 shows the preferred embodiment of the gas adsorber device according to the invention in the case of a mixture with three components MO / Pd, moisture adsorbing material and alloy based on barium and based on lithium; Figure 4 shows a graph related to the adsorption of a gas mixture by a gas adsorber device containing a combination of materials of the invention, as compared to the adsorption of the same gas mixture by a gas adsorber device of the invention. previous technique; Figure 5 shows a graph related to the adsorption of a gas mixture by a gas-containing device containing a combination of materials of the invention including the barium-based alloy and optional lithium-based; Figure 6 shows the comparison between the adsorption of carbon dioxide (CO2) by a gas adsorber device containing a combination of materials of the invention that includes an alloy based on barium and optional lithium base and an adsorber device gases of the prior art; Figure 7 shows a graph related to the adsorption of cyclopentane by a gas adsorber device containing a combination of materials of the invention; Figure 8 shows a graph related to the adsorption of an HCFC gas by a gas adsorber device containing a combination of materials of the invention; Figure 9 shows a graph related to the adsorption of a CFC gas by a gas adsorber device containing a combination of materials of the invention; Figure 10 shows a graph related to the adsorption of nitrogen by a gas adsorber device containing a combination of materials of the invention, including the barium-based alloy and optional lithium base, after adsorption of cyclopentane. The combination of gas adsorbing materials according to the invention is preferably used by placing it within a container, to have a compact, easy-to-handle gas adsorber device. The container is preferably made of a material that is gas impermeable and has an opening of a size such that the gases have access to the various gas adsorbing materials according to a given order. This is because it has been found that water vapor alters the properties of the MO / Pd mixture. The container is generally made of metals, which are impervious to gases. The preferred metals are aluminum, which has a light weight and is easy to machine at low cost; and stainless steel, when superior mechanical strength is desired, mainly for automated handling of gas adsorbing devices. A possible embodiment is illustrated in Figure 1, wherein a gas adsorber device 10 according to the invention is shown being formed of a container 11 made of aluminum, whose lower portion contains a mixture layer of MO / Pd 12, and the upper portion a dust layer of moisture adsorbing material 13. These materials can be introduced into the container in various ways, for example by emptying the powder into the container and subjecting it to light compression or by introducing some pre-formed pellets into the container. In both cases it is also possible that on the adjacent surface between the layers of different materials there are elements of mechanical separation that allow an easy passage of gaeee, such as redeems from plastic material, gauze, discs or porous paper (not shown in the figure). These elements help to keep the materials separated from each other and to contain fragments of material that can be produced as a result of impacts or eg, by swelling of the powders due to the adsorption of gases. Finally, the upper edge of the container 11 is slightly bent inwards, thus forming a retaining element 14 which keeps the gas adsorbing surface in the desired position. In another possible mode, the upper edge of the container does not bend inward. This embodiment is preferred when the gas adsorbing device is designed to be used in applications where the filler is a polymeric foam eg, polyurethane. In this case, a straight upper edge performs a cutting action and facilitates the insertion of the device into the p >; compressive foam anel, mainly in automated productions. This embodiment is shown in FIG. 1, in which the elements constituting the device are designated by the same numbers as in FIG. 1, with the exception of the element 15, which is the upper edge which is not bent. If the ternary combination of materials, which also includes a barium-based and lithium-based alloy, is used in the manufacture of the device, it must be considered that these alloys can react with the MO / Pd mixture, and in this way these two materials have to be kept separate; In addition, like the MO / Pd mixture, also the alloys based on barium and lithium are sensitive to water, so they must be protected from it. To carry out these conditions, various constructions of the gas adsorbing devices are possible. In the simplest embodiment, as shown in FIG. 2, a device 20 is used, composed of a container 21 that includes inside, when going from bottom to top, a layer 22 of MO / Pd mixture, a layer 23 of moisture dampening material, a layer 24 of a barium-based alloy and based on lithium and finally in contact with the external environment, a second layer 25 of moisture-adsorbing material. As in the device of figure 1, the upper edge of the container 21 can be bent inwards to thereby define a retaining element 26 which keeps the layers of various materials in the desired position. Alternatively, the upper edge of the container may be of the non-folded type, as in figure (not shown). Material layers 22 to 25 can now be introduced in the form of loose powders into the container 21 where they can possibly be subjected to a slight pressure to increase the mechanical stability of the layer, or pellets of the materials can be prepared separately for its subsequent introduction to the container 21. In both cases, it is possible to separate the different layers by means of mechanical separation elements such as polymeric gauzes or the like, not shown in the drawings, as described in the case of a device Figure 1. A preferred embodiment of the gas adsorber device also containing the barium-based and lithium-based alloy is shown in Figure 3. In this case, the gas adsorbing device 30 is composed of a first container 31 made of stainless steel or aluminum, which contains on its lower part a layer or a pellet 33 of mixture or pole of MO / Pd, a second fastener 32 made of stainless steel able is placed on layer 33 and filled with a barium-based alloy and lithium-based alloy 34. The assembly formed of powder mix of MO / Pd 33, fastener 32 and barium-based powder alloy based on lithium 34 is then coated with powder of a moisture adsorbing material 35. On the upper portion of the powder 35 exposed to the outside, a mechanical retention element is preferably placed to allow easy gas passage, such as a polymer network or gauze 36. As in structure 1, these polyrnical gauzes can also be placed on the MO / Pd layer and on the barium-based and lithium-based alloy powder to prevent the powders from mixing and to increase the stability mechanics of the resulting structure (these additional polyrnery gauzes are not shown in the drawing).

Finally, the upper edge of the container can be folded slightly into the interior thereby forming a retaining element 37 to maintain the resulting gas adsorbing structure in its position or it can be of the non-folded type to assist in the introduction of the device into polymer foam panels , as shown in the figure (the latter possibility is not shown in the drawings). Objects and advantages of the present invention will be more apparent to those skilled in the art from the following examples which have a merely explanatory purpose and do not limit the scope of the invention.

EXAMPLE 1 This example relates to the preparation of a gas adsorber device according to the invention. One gram of mixture of C? 3? <; / Pd which includes 10 rn of Pd, is placed on the bottom of a cylindrical stainless steel container that has a diameter of 28 rnm and a height of 4 rnm and is slightly pressed; on the layer of C? 3?; / Pd thus obtained, a gauze of a polymeric material is placed to keep the powder in the desired position. 4.5 g of BaO are introduced into the container, on this first layer, and then lightly pressed. The upper edge of the container is finally deformed by bending inwards so that both layers are maintained in their initial configuration, thus obtaining a device corresponding to that shown in Figure 1.

EXAMPLE 2 This example relates to the preparation of a second gas adsorber device of the invention comprising, in addition to the MO / Pd mixture and the moisture adsorption material, also a barium-lithium based alloy. Place 1 g of the mixture C? 3? .j / Pd, which contains 10 rng of Pd, on the bottom of a first cylindrical stainless steel support having a diameter of 28 mm and a height of 6 mm and is slightly squeezed on the layer obtained from C? 3? A / Pd a gauze of polymeric material is placed to keep the powder in the desired position. A second cylindrical steel support, having a diameter of 15 nm and a height of 3 mm, is prepared separately and filled with 0.25 g of BaLi alloy, slightly compressed and covered with a gauze of polymeric material. The support of the BaLÍ4 alloy is introduced into the first support, on the gauze that holds the mixture C? 3? «/ Pd. Then 4 g of powdered BaO are emptied to the first support until it completely covers both the mixture C 3 3 / Pd and the support with the BaL 4 alloy. The sprayed BaO is leveled, lightly compressed and covered with a gauze of polymeric material to keep it in position. Finally, the upper edge of the first support is slightly inclined internally to keep the entire structure in position, thus obtaining a gas adsorber device corresponding to that shown in Figure 3.

EXAMPLE 3 This example concerns the gas adsorption test by the gas adsorber device of example 1. The device according to example 1 is placed in a measuring chamber having a volume of 1.5 1, which is connected to a pressure gauge. capacity and, through interception valves, to gas inlet and outlet pipes. A gaseous mixture is introduced into the measuring chamber, which comprises 50% CO and 50% H2, as a simulation of a possible gaseous medium in a plastic jacket containing a filler, until it reaches a total chamber pressure of 0.32. mbarias. Finally, the chamber is closed and the pressure variations (barias) are monitored as a function of time (minutes). The result of the test, which is carried out at room temperature, is plotted in Figure 4 as curve 1.

EXAMPLE 4 (COMPARATIVE) The test of Example 3 is repeated, but using a gas adsorber device of the prior art instead of a gas adsorber device of the invention. The comparator gas adsorber device has a structure similar to that of Example 1, but contains 0.25 g of BaLIA and 4.5 g of BaO. The result of this test is plotted in Figure 4 as curve 2.

EXAMPLE 5 This example concerns the gas adsorption test by the gas adsorber device of example 2. The test of example 3 is repeated, except for the introduction, in the measuring chamber, of a gaseous mixture comprising 33.3% CO, 33.3 % H2 and 33.3% N2. The variations of pressure in the chamber are monitored as a function of time in the presence of the device of example 2. The result of the test is plotted in figure 5 as in curve 3, giving the total pressure in the chamber (mbarias) as a function of time (minutes).

EXAMPLE 6 This example concerns the gas adsorption test with a gas adsorber device similar to that of Example 1, where BaO is replaced by CaO. A gas adsorber device containing 2 g of CaO, 1 g of C03 O4 and 10 rn of Pd is introduced into a measuring chamber similar to that of Example 3, with a total volume of 0.74 1. The chamber is evacuated at a pressure of 1.33. • IQ-s mbarias. CO2 is then left in the chamber until a pressure of 0.86 mbar is reached, and pressure variations (mbarias) are monitored as a function of time (minutes). The result of this test is plotted in figure 6 as curve 4.

EXAMPLE 7 (COMPARATIVE) The test of example 6 is repeated, but using the gas adsorber device of the prior art of example 4. The result of this test is plotted in figure 6 as curve 5.

EXAMPLE 8 This example concerns the gas adsorption test with the gas adsorber device of example 2. The test of example 3 is repeated, except for the introduction of cyclopentane as the test gas in the measuring chamber. The variations in pressure in the chamber are monitored as a function of time in the presence of the device of example 2. The result of the test is plotted on a semilogarithmic graph in Figure 7 as curve 6, as the pressure (mbarias) as a function of the time (minutes) EXAMPLE 9 This example concerns the gas adsorption test with the gas adsorber device of example 1. The test of example 3 is repeated, except for the introduction of gas 141-b in the measuring chamber. The variations of the pressure in the chamber are monitored as a function of time in the presence of the device of example 1. The result of the test is plotted on a semilogarithmic graph in Figure 8 as curve 7, as the pressure (mbarias) in function of time (minutes).

EXAMPLE 10 This example concerns the gas adsorption test with the gas adsorber device of example 1. The test of example 3 is repeated, except for the introduction into the measuring chamber of the CFC gas, known as CFC 11. The variations of the pressure in the chamber are monitored as a function of time in the presence of the device of example 1. The result of the test is plotted on a semilogarithmic graph in Figure 9 as curve 8, as the pressure (mbarias) as a function of time (minutes) EXAMPLE 11 This example concerns the gas adsorption test with the gas adsorber device of example 2. After the completion of example 8, nitrogen is left in the chamber until a pressure of about 1.45 mbariae is reached. The camera closes and the pressure variations (mbarias) are monitored as a function of time (minutes). The result of this test is plotted in Figure 10 as the curve 9. Examining the results of Examples 3 to 10 it is clear that the combination of materials of the invention effectively absorbs all gases expected to enter the insulation shirts. thermal, and particularly to the panels for refrigerators, during its operation. In particular, it is seen that gases such as hydrogen and carbon onoxide are absorbed in a few minutes, whereas gas adsorbents of the prior art of low activation temperature require longer times; it is also seen that the combinations of the invention are unexpectedly capable of adsorbing organic gases, from hydrocarbons to hydrocarbons completely substituted by halogen, CFCs, through intermediate HCFCs; finally, the results of the tests show that nitrogen adsorption, representative of atmospheric gases, is not impaired by prior absorption (or, in operation, simultaneous) of organic gases. The combinations of materials of the invention and the devices containing them represent in this way a reliable solution to the problem of preserving the desired degree of vacuum inside thermal insulation jackets that can not withstand thermal treatment above 150 ° C and that They work at room temperature.

Claims (5)

1. NOVELTY OF THE INVENTION CLAIMS 1. A combination of gas adsorbing materials consisting of: a MO / Pd mixture of an oxide of a transition metal MO chosen from cobalt oxide, copper oxide or combinations thereof and palladium metal containing up to about 2% by weight of palladium metal; a moisture adsorbing material having a vapor pressure of H2O of less than 1 Pa at room temperature.
2. 2. A combination of gas adsorbing materials, according to claim 1, wherein the MO / Pd mixture is used in the form of a powder with a particle size of less than 500 μm.
3. 3. A combination of materials suitable for adsorbing. gases, according to claim 2, wherein the MO / Pd mixture is used in powder form with particle size between 1 and 200 μm.
4. 4. A combination of gas adsorbing materials, according to claim 1, wherein the moisture adsorbing material is chosen from the calcium, strontium, barium and phosphorus oxides or combinations thereof.
5. 5. A combination of gas adsorbing materials, according to claim 4, wherein the moisture adsorbing material has a particle size comprised between about 50 and 500 μm 6.- A combination of gas adsorbing materials, according to claim 4, in which pulverized alumina is added to the moisture adsorbing material. 7. A combination of gas adsorbing materials, according to claim 4, wherein the moisture adsorbing material is barium oxide. 8. A combination of gas adsorbing materials, according to claim 4, wherein the moisture adsorbing material is calcium oxide. 9. A combination of gas adsorbing materials, according to claim 1, wherein the weight ratio between the MO / Pd mixture and the moisture adsorbing material can vary between about 5: 1 and 15 1:20. 10. A combination of gas adsorbing materials, according to claim 9, wherein the ratio between the MO / Pd mixture and the moisture adsorbing material can vary between 1: 1 and 1: 5. 11. A combination of gas adsorbing materials, according to claim 1, further characterized in that it contains an alloy based on barium and lithium. 12. A combination of gas adsorbing materials, according to claim 11, wherein the • The alloy based on barium and lithium has a particle size of less than about 500 μm. 13. - A combination of gas adsorbing materials, according to claim 12, wherein the barium-lithium based alloy has a particle size of less than 150 μ. 14. A combination of gas adsorbing materials, according to claim 11, wherein the alloy based on barium and lithium is BaLi ". 15. A combination of gas adsorbing materials, according to claim 11, wherein the weight ratio between the mixture MO / Pd and the alloy based on barium and lithium can vary between approximately 10: 1 and 1: 5. 16. A combination of gas adsorbing materials, according to claim 15, wherein the weight ratio between the mixture MO / Pd and the alloy based on barium and lithium can vary between approximately 5: 1 and 1: 2. 17. A combination of gas adsorbing materials according to claim 11, wherein the weight ratio between the moisture adsorbing material and the lithium barium alloy can vary between about 50: 1 and 1: 5. . 18. A combination of gas adsorbing materials, according to claim 17, wherein the weight ratio between the moisture adsorbing material and the lithium barium alloy can vary between about 20: 1 and 1: 1 . 19. A gas adsorber device comprising: - a MO / Pd mixture between an oxide of a transition metal MO chosen from cobalt oxide, copper oxide or combinations thereof and metallic palladium, comprising up to 2% by weight of palladium metal; - a moisture adsorbing material having a vapor pressure of H2O of less than 1 Pa at room temperature; characterized in that only the moisture adsorbing material is directly in contact with the external medium. 20. A gas supply device, according to claim 19, formed as an open upward support (11), made of a gas-impermeable material and containing, when going in order from the bottom of the support towards the open end of the same support: - one layer of the MO / Pd mixture (12); -a layer of moisture adsorbing material (13). 21. A gas adsorber device, according to claim 20, in which the upper edge 14 of the support 11 is inclined internally. 22. A gas adsorber device, according to claim 20, in which the upper end 15 of the support (11) is not inclined internally. 23. A gas adsorber device, according to claim 20, characterized in that the support is made of a metal chosen between stainless steel and aluminum. 24. A gas adsorber device, according to claim 20, characterized in that the two different gas adsorbing materials are separated by mechanical separation members that allow the gases to flow easily therethrough. 25. A gas adsorber device comprising: - a MO / Pd mixture between an oxide of a transition metal MO chosen from cobalt oxide, copper oxide or its combinations and metallic palladium, including up to about 2% by weight of palladium metal; -an alloy based on barium and lithium; - a moisture adsorbing material having a vapor pressure of H2O of less than 1 Pa at room temperature; characterized in that only the moisture adsorbing material is directly in contact with the external medium. 26. A gas adsorber device, according to claim 25, being formed as an open upward support (21), made of a material impermeable to gases and comprising, going from the bottom of the support to the open end of the same: a layer (22) of a MO / Pd mixture; - a first layer (23) of moisture adsorbing material; - a layer (24) of an alloy based on barium and lithium; - a second layer (25) of moisture adsorbing material. 27. A gas adsorber device according to claim 26, in which the upper edge (26) of the support (21) is inclined internally. 28. A gas adsorber device, according to claim 26, wherein the upper edge The support surface (21) is not inclined internally. 29. A gas adsorber device, according to claim 25, consisting of: - a first support (31) open upwards and made of a gas-impermeable material; - a layer (33) of the MO / Pd mixture placed in the bottom of the first support; a second support (32) open upwards and positioned on the layer (33) so that the height of the second support added at the height of the layer (33) is smaller than the height of the first support, being measured on its inner side; - a barium-lithium based alloy (34) within the second support; - a moisture adsorbing material (35) within the first support (31) to completely cover the second support (32) and the layer (33) of the MO / Pd mixture. 30. A gas adsorber device, according to claim 29, further characterized in that the upper edge (37) of the first support (31) is inclined internally. 31.- A gas adsorber device, according to claim 29, characterized in that the upper edge of the first sop > orte (31) is not inclined internally. 32. A gas adsorber device, according to claim 29, characterized in that the first support (31) is made of aluminum and the second support (32) is made of stainless steel. 33.- A gas adsorber device, according to claim 29, characterized in that a mechanical retaining member (36) is placed on the layer (35) of moisture adsorbing material. 34.- A thermal insulation jacket made at least partially of plastic material containing a combination of gas adsorbing materials comprising: - a MO / Pd mixture between an oxide of a transition metal MO chosen from cobalt oxide, oxide copper or metallic combinations and palladium, including up to 2% by weight of palladium metal; and - a moisture adsorbing material having a vapor pressure of H2O of less than 1 Pa at room temperature. 35.- A thermal insulation jacket made at least partially of plastic material containing a combination of gas adsorbing materials comprising: - a MO / Pd mixture between an oxide of a transition metal MO, chosen among cobalt oxide, oxide of copper or its combinations and metallic palladium, including up to about 2% by weight of metallic palladium; - a moisture adsorbing material having a vapor pressure of H2O of less than 1 Pa at room temperature; and - an alloy based on barium and lithium.