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DEVICES AND METHODS OF EXTRACTING AND ACCUMULATION OF HYDROGEN AND OXYGEN
INVENTION
Patent of the Russian Federation RU2190571

METHOD FOR STORING HYDROGEN IN HARD CONDITIONS

METHOD FOR STORING HYDROGEN IN HARD CONDITIONS

The name of the inventor: Borisevich Yu.P .; Shcherbakov D.A.
The name of the patent holder: Samara State Technical University
Address for correspondence: 443010, Samara, ul. Galaktionovskaya, 141, SamSTU, the Patent Department, Yu.N.Klimochkin
Date of commencement of the patent: 1999.10.20

The method is designed for storing gases and can be used in the chemical, petrochemical and oil refining industries. The process is carried out by partially reducing the surface of gamma-alumina containing up to 1.28 × 10 18 / m 2 of adsorbed anions of hydrohalic acids and subjected to preliminary oxidation treatment at 500 ° C. in an oxygen stream, molecular, activated hydrogen or hydrogen-containing gas at 100-750 O C, a pressure of 1.0-10 atm and a gas humidity of 10 -5 -10 -1 vol.%. The partially reduced gamma alumina is then stored in an air of arbitrary humidity at a temperature of up to 125 ° C., in a vacuum or an inert gas atmosphere at a temperature 750 ° C and humidity up to 10 -5 % by volume and subsequent oxidation of the partially reduced surface of gamma-alumina with water vapor at 125-750 ° C in an inert gas atmosphere at atmospheric pressure or in a vacuum with a moisture content of 10 -5 -10 -2 volts .%. This method allows expanding the range of hydrogen storage conditions while maintaining safety and low costs.

DESCRIPTION OF THE INVENTION

The invention relates to methods for storing gases and can be used in the chemical, petrochemical and petroleum refining industries.

Methods of storing gases in a compressed, liquefied, absorbed and adsorbed state are known, but also in crystalline hydrate form and in the form of chemically transformed surfaces of solids [Fastovskii VG, Petrovskii Yu. V., Rovinsky AE. Cryogenic technology. M., 1974; Sidorenko M.V. Underground storage of gas. M.: Nedra, 1965; BSE, Moscow: Sov. Encyclopedia, 1970, vol. 2, p.467; Weller SW and Montagna AA Studies of Alumina 1. Reaction With Hudrogenat Elevated Temp. - J.Catal., 1971, v.21, 3, p.303-311; Amenomiya Y. Adsorption of Hydrogen and H 2 -D 2 Exchange Reaction on Alumina. - J.Catal., 1971, v.22, 1, p.109-122; Borisevich Yu.P., Fomichev Yu.V., Levinter ME Study of the interaction of hydrogen with the surface -Al 2 O 3 under conditions of variable humidity of the system. Academy of Sciences of the USSR. Journal of Physical Chemistry, 1985, issue 3; Borisevich Yu.P., Fomichev Yu.V., Levinter ME The study of the interaction of hydrogen with the surface -Al 2 O 3 . Journal of Physical Chemistry, 1981, Vol.55, issue 8, p. 2149-2151; Patent (Russian Federation) 2,048,435. A method for long-term storage of hydrogen. Borisevich Yu.P.].

Disadvantages of these methods with respect to hydrogen are: large technical difficulties and high costs for liquefying hydrogen due to its extremely low boiling point, large storage losses due to the same reason, increased fire and explosion hazard of liquid hydrogen, and the need to use either liquefied hydrogen or pure hydrogen , Or special devices for separating gases from it that condense at higher temperatures; Compression of hydrogen and a rather complex and expensive process, which, while minimizing storage losses, does not reduce the fire and explosion hazard, which adds considerable complexity to the operation of vessels operating under considerable pressure and characterized by high metal content, in addition, obtaining and Storage of compressed hydrogen requires its original purity; Storage of hydrogen in the adsorbed and absorbed state is practically not used in engineering (it is possible, except for the case of its dissolution in palladium), since it is characterized by low retention of all known adsorbents and absorbents, many of which are rare and precious substances (for example, noble metals) , Often incomplete reversibility during desorption and the impossibility of long-term storage of hydrogen in a similar state both as a result of technical inconveniences and because of oxygenation of air; Storage of hydrogen in the crystalline hydrate form of industrial importance (unlike hydrocarbon gases) and does not, as for obtaining and storing such a substance, difficult-to-reach conditions associated with high costs are required; The storage of hydrogen in the form of partially reduced gamma alumina for industrial use has not been obtained, since either the hydrogen storage is stored only in flowing hydrogen and only at atmospheric pressure, whereby the total amount of hydrogen "stored" is much less than the amount of hydrogen , Consumed to restore the surface, and accordingly, the amount of hydrogen "derived from the storage" is much less than the amount of hydrogen spent to restore the surface, or for the sake of increasing the "storage capacity" is sacrificed by a range of storage conditions.

The closest to the technical essence and achieved effect to the proposed method is the storage of hydrogen [Patent (Russian Federation) 2125537 Method of storage of hydrogen. Borisevich Yu.P.], based on the partial reduction of gamma-alumina containing up to 3.7 × 10 17/1 m 2 adsorbed anions of organic acids and subjected to preliminary oxidative treatment at 500 ° C in an oxygen stream, molecular or activated hydrogen, Or hydrogen-containing hydrocarbon gas, followed by surface oxidation with water vapor accompanied by evolution of hydrogen. The drawbacks of the known method are the principle limitations on the range of storage conditions for partially reduced gamma alumina, as a result of which the maximum storage temperature in the air of arbitrary humidity does not exceed 50 ° C., which clearly leaves much to be desired.

The object of the invention is to extend the range of storage conditions of partially reduced gamma alumina in an air of arbitrary humidity in the direction of tightening the thermal conditions while maintaining safety and low storage costs.

The aim is achieved by the described method of partial reduction of gamma-alumina containing up to 1.28 × 10 18/1 m 2 of adsorbed hydrogen halide anions and subjected to preliminary oxidation treatment at 500 ° C in an oxygen flow in a closed volume by molecular, activated hydrogen or hydrogen-containing Hydrocarbon gas with freezing of the water formed at a temperature of 100 to 750 ° C., a pressure of 1 to 10 atm and a gas humidity of from 10 -5 to 10-1 % by volume ("hydrogen storage deposit"), followed by oxidation of the partially reduced gamma- Alumina with water vapor ("production of hydrogen from storage") at temperatures of 100 to 750 ° C in an inert gas atmosphere at atmospheric pressure or a vacuum with a moisture content of 10 -5 to 10 -2 % by volume, carried out after a short-term or long-term storage in part (With a specific surface area of ​​200 to 400 m 2 / g) in an air of arbitrary humidity at temperatures up to 125 ° C, a vacuum or an inert gas medium at an arbitrary temperature 750 ° С and humidity up to 10 -5 % vol.

The essential difference between the proposed method and the known ones is that for the first time a partial reduction of a solid by molecular or activated hydrogen or hydrogen-containing hydrocarbon gas is carried out only after preliminary oxidative treatment at 500 ° C in an oxygen stream, having previously been applied to it by ion exchange to 1, 28 · 10 18/1 m 2 anions of hydrohalic acids.

The novelty of the claimed technical solution is that gamma-alumina, partially reduced after preliminary oxidative treatment at 500 ° C in an oxygen stream, is used as the hydrogen storage, containing on its surface up to 1,28 · 10 18/1 m 2 anions of halogenated acids , Deposited by means of ion exchange, with the freezing out of water released during the recovery, which can then be stored in air, in an inert gas or vacuum, without losing the ability to separate hydrogen in strict accordance with the enclosed volume by oxidation of the previously partially reduced surface of gamma-alumina with water vapor .

It is known that according to the law of electrostatic valence [Pauling L. The Nature of Chemical Bond, 3 rd. Ed., Cornell Univ. Press. Jthaca, New York, 1960, p. 548], the operating charge in a stable ionic structure should be equal to or approximately equal to zero. Since this requirement is better satisfied by OH groups rather than oxygen, the anionic layer which, according to the energy principles, must limit the surface of the crystalline gamma-alumina is preferably a hydroxyl layer.

It is known that molecular and activated hydrogen at a temperature of 100 to 750 o C and a gas humidity of 10 -5 to 10-1 vol% in flow conditions can partially restore the surface of gamma-alumina. [Borisevich Yu. P. The interaction of hydrogen with the surface -Al 2 O 3 and its role in the processes of dehydrogenation and dehydrocyclization. The dissertation author's abstract on competition of a scientific degree kand. Chem. N. Minsk, AN BSSR, Institute of Physical and Organic Chemistry]. Since the interaction of hydrogen with gamma-alumina is accompanied by additional dehydroxylation of the surface compared to calcination in a vacuum or an inert gas environment in the same temperature range, the resulting surface defects are fundamentally different from surface defects obtained by dehydroxylation of gamma-alumina in a vacuum or an inert gas atmosphere , Which predetermines the ability of the oxide in question to act as a "storehouse" of hydrogen. Dehydroxylation of gamma-alumina in an inert medium or vacuum, proceeding according to the mechanism proposed by Peri JB [Peri JB A Model for the Surface of - Alumina .- J. Phys. Chem. , 1965, v.69, 1, p.220-231], is accompanied by the formation of a surface layer of oxygen anions, while in dehydroxylation in a hydrogen medium, the surface hydroxyl groups are removed much more completely (in the form of H 2 O), as a result of which it is exposed Layer of positively charged aluminum ions, which allows us to consider the interaction of aluminum oxide with hydrogen as a process of surface reduction.

The deposition of gamma-alumina ions on the surface by means of ion exchange of hydrogen halide anions, which remain on the surface after oxidative treatment, will lead to a change in the nature of the defects formed, and this will inevitably change the conditions for the subsequent oxidation of the partially reduced surface, which in turn will shift the temperature range of hydrogen storage conditions , "Pledged for safekeeping". In this case, since the surface hydroxyl groups of alumina have a certain distribution in the strength of basicity, then when they are ionically exchanged with hydrohalic acids of different strength, the acid having a large dissociation constant will be less selectively adsorbed. In this case, most of the hydroxyl groups on the surface of gamma-alumina, usually stable during oxidative treatment and interaction with hydrogen, will be replaced by acid anions, and this will inevitably lead to a greater number of surface defects. An increase in the number of surface defects in this case is equivalent to an increase in the capacity of the "storage", which is explained by the partial removal of hydroxyl groups due to ion exchange, which are most stable upon reduction but unable to withstand the action of an aqueous solution of hydrohalic acids. The upper limit of the concentration of applied anion halogen acids (1.28 · 10 18/1 m 2 ) is due to the concentration on the surface of gamma-alumina hydroxyl groups, usually resistant to surface restoration. The lower limit of the concentration of applied anions of halogenated acids (0/1 m 2 ) is due to the distinctive features of the claimed method.

For each reduction temperature, the degree of removal of OH groups is determined by the humidity of the system. Reducing the humidity of the system (freezing H 2 O) shifts the equilibrium towards the stable existence of the reconstructed surface. The amount of hydrogen, which is potentially "stored for storage," is increasing. The increase in the humidity of the system shifts the equilibrium towards the hydration of the surface. The amount of hydrogen that is potentially "stored for storage" decreases. Thus, for each reduction temperature, there is a moisture limit, exceeding which makes recovery impossible. As the reduction temperature increases, the amount of hydrogen that is potentially "stored" increases up to the maximum possible system for the given humidity and the specific surface area of ​​the gamma-alumina sample. With the increase in the specific surface area of ​​aluminum oxide, the "storage capacity" naturally increases (even during the fragmentation of the sample), up to the darkening of the surface during recovery. As the hydrogen pressure increases, the "storage capacity" increases during the recovery, and the maximum capacity at the same humidity values ​​of the system and the specific surface can be reached at lower temperatures, which is explained by the greater ease of removal of OH groups with increasing hydrogen pressure.

Application for the regeneration of activated hydrogen (activation can be carried out either by means of a high-frequency discharge, or by the Shillover or Jampover phenomenon in the case of using platinum black or a platinum catalyst on a carrier, or, finally, using -radiation) further facilitates the process of reducing the surface of gamma-alumina due to the much higher reactivity of activated hydrogen compared to molecular, which allows to achieve a single "storage capacity" at the same humidity values ​​of the system, the oxide specific surface area and pressure at much lower Temperatures.

Finally, the restoration of the surface of gamma-alumina is quite possible and hydrogen-containing hydrocarbon gas (in the absence of oxygen in it, capable of causing reverse oxidation of the surface under the given conditions). The degree of reduction of the surface of gamma-alumina, other things being equal, is determined by the partial pressure of free hydrogen, with heavy hydrocarbons capable of causing partial coagulation of the gamma-alumina surface, which somewhat reduces the "storage capacity".

Of course, for the equilibrium shift, the oxidation <-> reduction of the surface of gamma-alumina, carried out in a closed volume (in order to save hydrogen) in the direction of surface restoration during the "hydrogen storage", requires freezing out the formed moisture, which is most easily done with zeolites (For example, NaX), cooled to the temperature of liquid nitrogen. In this case, if the consumption of hydrogen when restoring the surface of gamma-alumina is not a limiting factor, the process can be carried out on the duct without freezing the formed moisture. The upper temperature limit for the reduction of the surface of gamma-alumina (750 ° C) is limited by the sintering of gamma-alumina. As a result of which the specific surface area of ​​the oxide (and hence the "storage capacity") begins to decline sharply. The lower temperature limit for the reduction of the surface of gamma-alumina (100 ° C) is limited by the reactivity of hydrogen with respect to alumina. The lower limit of the moisture content of the gas in the reduction of gamma-alumina (10 -5 % by volume) is limited only by the technical difficulties of deeper dehydration of the gas. The upper limit of the moisture content of the gas in the reduction of gamma-alumina is limited by a shift in the equilibrium of the oxidation <-> surface restoration to the extreme left, in which no surface reduction becomes impossible even at the highest temperatures of the patent range. The lower limit of hydrogen pressure (or the hydrogen partial pressure in the case of hydrocarbon hydrogen-containing gas) - 1 atm - is limited by the minimum "storage capacity" at which this method is still advisable, with further pressure decrease the potentialities of gamma-alumina remain almost completely unrealized. The upper limit of hydrogen pressure (10 atm) is limited by the technical difficulties in hydrogen compression, and most importantly, by too deep reduction of the gamma-alumina surface, at which the future oxidation by water vapor becomes difficult in the patentable temperature range.

After the reduction of the gamma-alumina surface ("hydrogen storage for storage") and cooling to room temperature in the reduction medium, the oxide is completely ready to store hydrogen either in an air of arbitrary humidity at a temperature of up to 125 ° C. or in a vacuum or an inert gas environment An arbitrary temperature (up to 750 o C) and humidity up to 10 -5 vol.%.

The upper limit (125 ° C.) of the stored oxide in the air is due to the impossibility of water vapor of any concentration to cause a significant oxidation of the reduced surface of gamma-alumina (with evolution of hydrogen) to the indicated temperature because of their insufficient reactivity.

The upper limit of humidity (10 -5 % by volume) during storage of the reduced oxide in a vacuum or in an inert gas environment at an arbitrary temperature (up to 750 ° C) is caused by the impossibility of water vapor (due to their negligible concentration) to cause significant oxidation of the previously reduced surface (with evolution of hydrogen ) Until the sintering of the oxide surface begins.

The production of hydrogen from the storage facility is associated with the oxidation of the previously reduced surface of gamma-alumina with water vapor, while the original hydroxyl coating of the solid is completely restored. The amount of hydrogen "obtained from the storage" is determined by the depth of oxidation of the previously reduced surface of gamma-alumina, which is proportional to the temperature and humidity of the medium during oxidation. Moreover, for each reduction degree of gamma-alumina there is a moisture limit below which oxidation becomes impossible and a limit equal to 10 -5 % by volume above which for any reduction in the oxidation temperature range of 125-750 ° C all Hydrogen, "previously stored". The lower temperature limit for the oxidation of the surface of the pre-reduced gamma-alumina oxide (125 ° C) is due to the fact that at lower temperatures even at the highest humidities of the system the oxidation of the partially reduced oxide can not be complete, that is, the amount of hydrogen "extracted from the storage ", Will be substantially less than the amount of hydrogen" stored for storage ". The upper temperature limit for the oxidation of the surface of the pre-reduced gamma-alumina (750 ° C) is due to the thermal stability of the gamma-alumina surface to sintering, i.e. At higher temperatures, a decrease in the specific surface area of ​​gamma-alumina is observed, which means that the "storage capacity" is reduced to re-store hydrogen for storage.

The lower limit of the humidity of the system during the oxidation of the surface of the pre-reduced gamma-alumina (10 -5 vol.%) Is due to the reactivity of water vapor, which at lower concentrations is not capable of completely oxidizing the surface of gamma-alumina even at the highest temperatures (750 ° C ), I.e., the amount of hydrogen "recovered from storage" will be less than the amount of hydrogen "stored for storage".

The upper limit of the humidity of the system during the oxidation of the surface of the pre-reduced gamma-alumina (10 -2 vol%) is due to the reactivity of water vapor, which, even at this concentration, is able to completely extract hydrogen from the storage, even when heated to the maximum temperature, Simply impractical.

The above disadvantages associated with the storage of hydrogen by traditional methods can be overcome if the process of oxidation-reduction of gamma-alumina after preliminary oxidative treatment of the surface with the deposited anions of hydrohalic acids is used for storage.

Such a technical solution is provided in the proposed method.

Example 1 . The sample (50 grams) of gamma alumina (0.2-0.5 mm) with a specific surface area of ​​200 m 2 / g in a closed volume was partially reduced by molecular hydrogen (with the absorption of the produced water by clinoptilolite cooled with liquid nitrogen) under thermo-programmed heating with At a rate of 40 ° C./min to a temperature of 750 ° C. with a hold at 750 ° C. for an hour, a pressure of 1 atm, and a gas humidity of 10 -5 % by volume. When the sample of gamma alumina was held at 750 ° C. for one hour, the pressure and humidity of hydrogen were maintained at the initial level. After cooling in the reduction medium to room temperature and storing the partially reduced oxide in a humid air atmosphere (room conditions) at a temperature of up to 50 ° C for two months, the oxide was treated with water vapor in a helium medium (humidity 10-2 vol.%) At atmospheric pressure and (40 ° C./min.) Heating to 750 ° C. After about one hour at 750 ° C., 4 liters of H 2 (nu) / 1 liter of gamma-alumina were recovered from the storage. Thus, Example 1 serves as a reference (does not contain the entire set of essential features reflected in the claims) to compare the claimed invention with the already known method of storing hydrogen under mild conditions (the storage temperature did not exceed 50 ° C), without modifying the surface with anionic inorganic acids [ Patent (Russian Federation) 2125537 Method of storage of hydrogen. Borisevich Yu.P.]

Example 2 . Unlike Example 1, the storage temperature of the partially reduced sample of gamma-alumina was changed to 125 ° C. From the storage, 3.52 L H 2 (nu) / 1 L gamma alumina was obtained. Thus, Example 2 serves as a reference (does not contain the entire set of essential features reflected in the claims) to compare the claimed invention with the already known method of storing hydrogen with gamma-alumina without modifying the surface with anionic inorganic acids, but already with stricter storage conditions The storage temperature reached 125 ° C).

Example 3 . In contrast to Example 1, the surface of a sample of gamma-alumina was ionically exchanged from an aqueous solution of 1.28 × 10 18/1 m 2 anions of hydrochloric acid, and the sample itself after drying was subjected to a preliminary oxidation treatment at 500 ° C. in Flow of oxygen. From the storage, 2 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained. Thus, the "storage capacity" compared to the benchmark has decreased by 50%. Hence, the claimed invention is inferior to the known method under mild storage conditions and mild reduction conditions (1 atm).

Example 4 . Unlike Example 3, the storage temperature of the partially reduced sample of gamma alumina was changed to 125 ° C. From the storage, 2 L H 2 (nu) / 1 L gamma alumina was obtained. Thus, the "storage capacity" compared to the benchmark has decreased by 42%. Hence, the claimed invention is inferior to the known method under severe storage conditions, but still with mild reduction conditions (1 atm).

Example 5 . In contrast to Example 3, 0.64 × 10 18/1 m 2 of hydrochloric acid anions was applied to the surface of a sample of gamma-alumina. From the storage, 3 liters of H 2 (n.a.) / 1 liter of gamma-alumina were obtained. Thus, the "storage capacity" has decreased by only 25%; But this is still worse than the known method.

Example 6 . In contrast to Example 3, the surface of a sample of gamma-alumina was ionically exchanged from an aqueous solution of 1.28 × 10 18/1 m 2 of hydrofluoric acid anions. From the storage, 2.4 liters of H 2 (n.u.) / 1 liter of gamma-alumina were obtained. Thus, the replacement of inorganic anions only insignificantly increased the "storage capacity", which is still inferior to the standard.

Example 7 . In contrast to Example 1, a partial reduction of gamma-alumina was carried out at 10 atm. From the storage, 10 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained. Thus, Example 7 serves as a reference (does not contain the entire set of essential features reflected in the claims) to compare the claimed invention with the already known method of storing hydrogen under mild conditions, but under severe reduction conditions (10 atm).

Example 8 . In contrast to Example 3, a partial reduction of the gamma-alumina surface was carried out at 10 atm. From the storage, 14 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained. Thus, under the severe conditions of recovery (and still mild storage conditions), the advantages of the claimed method begin to manifest. The storage capacity increases by 40%.

Example 9 . In contrast to Example 2, a partial reduction of the gamma-alumina surface was carried out at 10 atm. From the storage, 8 liters of H 2 (n.u.) / 1 liter of gamma-alumina were obtained. Thus, Example 9 serves as a reference (does not contain the entire set of essential features reflected in the claims) to compare the claimed invention with the already known method of storing hydrogen under harsh conditions and under severe recovery conditions (10 atm).

Example 10 In contrast to Example 4, a partial reduction of the gamma-alumina surface was carried out at 10 atm. From the storage, 12 liters of H 2 (n.a.) / 1 liter of gamma-alumina were obtained. Thus, under severe recovery conditions (and harsh storage conditions), the advantages of the claimed method are fully manifested. The storage capacity is increased by 50%.

Example 11 . In contrast to Example 1, a partial reduction of gamma-alumina was carried out at 5 atm. From the storage, 7 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 12 . In contrast to Example 1, gamma alumina with a specific surface area of ​​400 m 2 / g was used for partial surface reduction. From the storage, 8 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 13 . In contrast to Example 1, gamma alumina with a specific surface area of ​​300 m 2 / g was used to partially reconstruct the surface. From the storage, 6 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 14 . In contrast to Example 1, a partial reduction of the gamma-alumina surface was carried out at a humidity of the system of 10 -1 vol.%. From the storage, 0.34 l of H 2 (nu) / 1 l of gamma-alumina was obtained.

Example 15 . In contrast to Example 1, a partial surface reduction was carried out at a humidity of 10 -3 vol%. From the storage, 1.5 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 16 In contrast to Example 1, a partial reduction of the gamma-alumina surface was carried out at 600 ° C. 0.2 L H 2 (nu) / 1 L gamma-alumina was recovered from the storage.

Example 17 In contrast to Example 1, a partial reduction of the gamma-alumina surface was carried out with hydrogen activated on a platinum catalyst at 100 ° C. From the storage, 1 L H 2 (nu) / 1 L gamma alumina was obtained.

Example 18 . In contrast to Example 14, a partial reduction of the gamma-alumina surface was carried out at 750 ° C. From the storage, 12 L H 2 (nu) / 1 L gamma alumina was obtained.

Example 19 . In contrast to Example 18, 1.28 × 10 18/1 m 2 of hydrochloric acid anions was applied to the surface of a sample of gamma-alumina. From the storage, 6.2 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 20 . In contrast to Example 1, a partial reduction of the gamma-alumina surface was carried out with a hydrogen-containing hydrocarbon gas (85 vol% H 2 and 15 vol% CH 4 ). From the storage, 3.75 L H 2 (nu) / 1 L gamma-alumina was obtained.

Example. 21 . Unlike Example 1, the reduced alumina was stored for 1.5 years. From the storage, 3.95 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 22 . Unlike Example 1, the reduced alumina was stored in a vacuum (P = 0.1 mm Hg). From the storage, 4.1 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 23 . In contrast to Example 1, the reduced alumina was stored in helium at an arbitrary (up to 750 ° C.) temperature and humidity of the system to 10 -5 % by volume. From the storage, 4.1 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 24 . In contrast to Example 1, the production of hydrogen from the storage was carried out at a humidity of the system of 10 -5 % by volume. From the storage, 0.22 L H 2 (n.u.) / 1 L gamma-alumina was obtained.

Example 25 . In contrast to Example 1, the production of hydrogen from the storage was carried out at a humidity of the system of 10 -3.5 % by volume. 1.3 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained from the storage.

Example 26 . In contrast to Example 1, the production of hydrogen from the storage was carried out by thermally programmed heating to 125 ° C and holding at 125 ° C for 1 hour. From the storage, 0.2 liters of H2 (nu) / 1 liter of gamma oxide Aluminum.

Example 27 . In contrast to Example 1, the production of hydrogen from the storage was carried out by thermally programmed heating to 400 ° C. From the storage, 1.85 L H 2 (nu) / 1 L gamma alumina was obtained.

Example 28 . Unlike Example 1, the production of hydrogen from the storage was carried out in a vacuum at the same humidity of the system. From the storage, 4 liters of H 2 (nu) / 1 liter of gamma-alumina were obtained.

Example 29 . A sample (50 g) of gamma-alumina (0.2-0.5 mm) with a specific surface area of ​​200 m 2 / g, to the surface of which 1.28 · 10 18/1 m 2 was applied to the surface by ion exchange from an aqueous solution Anions of hydrochloric acid, after drying, it was oxidized at 500 ° C in an oxygen stream followed by a partial reduction of the surface in a closed volume by molecular hydrogen (preliminarily cooled in an oxygen flow and purging with an inert gas at room temperature and absorbing the water-formed clinoptilolite, Cooled by liquid nitrogen) under thermo-programmed heating at a speed of 40 ° C./min to a temperature of 750 ° C. with a hold at 750 ° C. for an hour, a pressure of 1 atm and a gas humidity of 10 -5 % %. When the sample of gamma alumina was held at 750 ° C. for one hour, the pressure and humidity of hydrogen were maintained at the initial level. After cooling in the reduction medium to room temperature, purging with inert gas at room temperature, and storing the partially reduced oxide in an air of arbitrary humidity for a period of two months (room conditions) at a temperature of up to 125 ° C., the oxide was treated with water vapor in helium (humidity 10 -2 Vol.%) At atmospheric pressure and thermally programmed (40 ° C./min.) Heating to 750 ° C. After 1 hour at 750 ° C. and cooled in an oxidation atmosphere to room temperature, 2 liters of H 2 (n.u.) / 1 l of gamma-alumina.

The data given and examples 1-29 were obtained by laboratory studies of the oxidation processes of <-> reduction of real samples of gamma-alumina.

From the foregoing examples, it follows that if the conditions of storage and reduction of gamma-alumina are toughened, the advantages of the patented method (expressed in increasing the capacity of the storage), while maintaining safety and low costs, become OBJECTIVE.

CLAIM

A method for storing hydrogen under stringent conditions, including partial reduction of gamma-alumina with a specific surface area of ​​200-400 m 2 / g molecular, activated hydrogen or hydrogen-containing hydrocarbon gas at 100-750 ° C, a pressure of 1-10 atm and a gas humidity of 10 -5 -10 -1 vol. % With the freezing of the formed water, storage of partially reduced gamma-alumina in an air of arbitrary humidity at a temperature of up to 125 ° C., in a vacuum or an inert gas atmosphere at a temperature 750 o С and humidity up to 10 -5 vol. % And the subsequent oxidation of partially reduced gamma-alumina with water vapor at 125-750 ° C in an inert gas atmosphere at atmospheric pressure or in a vacuum with a moisture content of 10 -5 -10 -2 vol. %, Characterized in that the partial reduction is subjected to a preliminary oxidation treatment at 500 ° C. in an oxygen stream, gamma-alumina containing, on its surface, up to 1.28 × 10 18/1 m 2 anions of hydrogen halide ions supported by ion exchange, This storage of the partially reduced gamma-alumina in air is conducted at a temperature of up to 125 ° C.

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Date of publication 28.02.2007gg