RU2345829C2 - Composition for production of hydrogen, method of its preparation and device for hydrogen generation - Google Patents

Abstract

FIELD: technological processes; chemistry.

SUBSTANCE: composition includes magnesium hydride, binder, sulfuric acid and sulfuric acid sorbate. As sulfuric acid sorbate it contains material selected from group that includes aerogels of silicon dioxide, titanium dioxide, zinc oxide, aluminium oxide, and as binder it contains substance selected from the following group: fluoroplastic, polyethylene, polypropylene. Composition for hydrogen preparation is prepared by sorption of sulfuric acid by sorbate, moulding of magnesium hydride with binder in the form of tablets, pellets or granules. Sulfuric acid sorbate used is material selected from the group containing aerogels of silicon dioxide, titanium dioxide, zinc oxide, aluminium oxide, and binder used is substance selected from the group comprising fluoroplast, polyethylene, polypropylene. Device for hydrogen generation includes reactor made in the form of communicating vessels that contains composition for hydrogen generation, device for water dispensing. Specified reactor is equipped with reduction gear with feedback for hydrogen exhaust. Device is arranged in the form of U-shaped vessel that contains the above mentioned composition.

EFFECT: possibility to generate highly pure hydrogen.

3 cl, 3 dwg, 7 ex

Description

The present invention relates to the field of chemistry dealing with the production of hydrogen, compositions designed to accomplish this task, methods for producing such compositions and apparatuses for generating hydrogen, which can then be used to power fuel cells that ensure the operability of various portable devices and devices, for example cell phones, receiving and transmitting field radio equipment, laptops, etc.

A known composition for controlled and controlled hydrogen generation containing 5-10 wt.% Homogenizing liquid (mineral oil, pentane or hexane), a dispersing agent (such as oleic acid triglyceride) and 90-95 wt.% Binary or complex hydride (for example, LiH or LiAlH ₄ , NaH or NaBH ₄ and NaAlH ₄ , MgH ₂ , CaH ₂ ). Hydrogen evolution occurs during controlled decomposition of the composition in contact with water (Canadian Patent 2434650, IPC ⁷ C01B 3/08, B01J 7/00, C01B 6/04, C01B 6/24. Storage, generation, and use of hydrogen / Kondari RK , Larsen Ch. A., Rolfe JL, McClaine AW // 08.29.2002; European patent 1355849, IPC ⁷ C01B 3/08, B01J 7/00, C01B 6/04, C01B 6/24. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002; Application US 2002166286, IPC ⁷ C10J 1/00; B01J 7/00. Storage, generation, and use of hydrogen / Kondari RK , Larsen Ch. A., Rolfe JL, McClaine AW // 11/14/2002; International application 02066369, IPC ⁷ C01B 3/08; C01B 6/04, C01B 6/24, B01J 7/00. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002).

The disadvantages of this composition are alkalization of the solution and the cessation of hydrogen evolution in the case of NaBH ₄ , the possibility of a sharp increase in the rate of hydrolysis up to explosion in the case of NaH, LiAlH ₄ and NaAlH ₄ , uncontrolled interaction and gradual attenuation of the hydrolysis reaction and the rate of hydrogen evolution in the case of MgH ₂ and CaH ₂ , caused by the limited solubility of the resulting hydroxides in water (the values of the solubility product of PR for Mg (OH) ₂ and Ca (OH) ₂ are 6.0 × 10 ^-10 and 5.5 × 10 ^-6, respectively). Since the densities of a homogenizing liquid (oil, pentane or hexane) and a dispersing agent such as oleic acid triglyceride (0.7-0.9 g / cm ³ ) are noticeably lower than the hydride density (≈1.6 g / cm ³ ), sedimentation processes are quite real and caking the composition during storage. Mixing a suspension of hydride in a dispersant solution requires energy. The ingredients of the composition are a homogenizing organic liquid and a dispersing agent, which, according to the technical solution, impede the rapid sedimentation of metal hydride, and the composition foams during hydrogen generation and the carrier organic liquid enters the generated hydrogen. In addition, when using sodium borohydride, highly toxic and fire hazardous borohydrates are formed.

A known method of preparing a composition for generating hydrogen (Canadian Patent 2434650, IPC ⁷ C01B 3/08, B01J 7/00, C01B 6/04, C01B 6/24. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A ., Rolfe JL, McClaine AW // 08/29/2002; European patent 1355849, IPC ⁷ C01B 3/08, B01J 7/00, C01B 6/04, C01B 6/24. Storage, generation, and use of hydrogen / Kondari RK , Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002; Application US 2002166286, IPC ⁷ C10J 1/00; B01J 7/00. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A ., Rolfe JL, McClaine AW // 11/14/2002; International application 02066369, IPC ⁷ C01B 3/08, C01B 6/04, C01B 6/24, B01J 7/00. Storage, generation, and use of hydrogen / Kondari RK , Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002), including mixing hydride with a mixture of homogenies fluid and triglyceride, after which the composition is converted into a stable suspension.

The disadvantages of the known method of preparation of the composition are associated with the inability to obtain a stable suspension of components with different density and sedimentation of the suspension during storage.

A known apparatus for generating hydrogen, including a vessel for a suspension of a metal hydride and a mechanism for supplying a reagent (in particular water) to various portions of a suspension containing a metal hydride (Canadian Patent 2434650, IPC ⁷ C01B 3/08, B01J 7/00, C01B 6 / 04, С01В 6/24. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002; European patent 1355849, IPC ⁷ С01В 3/08, B01J 7 / 00, СВВ 6/04, СВВ 6/24. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002; Application US 2002166286, IPC ⁷ C10J 1 / 00; B01J 7/00. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A., Rolfe JL, McClaine AW // 11/14/2002; International application 02066369, IPC ⁷ C01B 3/0 8; С01В 6/04, СВВ 6/24, B01J 7/00. Storage, generation, and use of hydrogen / Kondari RK, Larsen Ch. A., Rolfe JL, McClaine AW // 08/29/2002). The reagent supply mechanism may include pipelines provided with a system for dispensing the reagent to individual portions of the suspension.

The disadvantages of this apparatus are: the inability to realize effective and controlled hydrogen evolution caused by alkalization of the reaction medium due to the formation of alkali metal hydroxides or, in the case of calcium and magnesium hydrides, the limited solubility of the resulting hydroxides in water, and the complexity of the design.

A device for producing hydrogen is also known, including a vessel filled with water and a deformable container filled with a liquid material capable of reaction with water, in particular calcium, lithium or magnesium hydrides, mixed with oil or mineral oil (UK Patent 1425590, IPC ⁷ B01J 7 / 02. Gas generating devices / France Armed Forces. // 02/18/1976; French patent 2207885, IPC ⁷ B01J 7/02. Gas generating devices / France Armed Forces. // 02/18/1976; US patent 3902425, class 120/531. Gas generator device within an enclosure / BJKurtzemann. // 02.09.1975).

The disadvantages of this technical solution are the slow uncontrolled evolution of hydrogen in the case of MgH ₂ and CaH ₂ due to the limited solubility of the resulting hydroxides in water (the values of the solubility product of PR for Mg (OH) ₂ and Ca (OH) ₂ are 6.0 × 10 ^-10 and 5.5 × 10 ^-6, respectively), foaming the suspension during the generation of hydrogen, the ingress of oil or mineral oil into the generated hydrogen and sedimentation of heavier metal hydride compared to oil or mineral oil during storage. Within the framework of this technical solution, dosed (on demand) hydrogen evolution is impossible.

A device for generating hydrogen is also known (UK Patent 2290784, IPC ⁷ C01B 3/06, B01J 7/02. Reactor for generating hydrogen from metal hydride and water / Adlhart OJ // 10.01.1996; US Patent 5514353, IPC ⁷ B01J 007 / 00. Demand responsive hydrogen generator based on hydride water reaction / Adlhart OJ // 05/05/1996), in which the supplied controlled water enters the cartridge, made in the form of a wavy perforated sheet of metal coated with a porous material (inorganic or organic fibers, plastics), in which metal hydride is dispersed (CaH ₂ , LiH, LiAlH ₄ , LiBH ₄ ). According to the technical solution, hydrogen evolution begins after water enters the capillaries of the material and ceases after the water supply ceases.

The disadvantages of this technical solution are the impossibility of a controlled evolution of hydrogen due to diffusion difficulties caused by the low solubility of calcium hydroxide, the inapplicability of the indicated technical solution to other hydrides, in particular magnesium hydride, the evolution of boron hydrogen during the hydrolysis of LiBH _4, and the hydrophilicity of a material that capillarily absorbs water in therefore, the process of hydrogen generation stops only when water is completely consumed.

A method is described for intensifying the interaction of water (or water acidified with hydrochloric acid) with nanocrystalline hydrides of elements containing at least one of the elements from the group Mg, Li, Be, Ca, Na, K, Al, Ti, V, Cr, Mn , Co, Ni, Cu, Fe, Zn, B, Zr, Y, Nb, Mo, In, Sn, Si, H, C, O, F, P, S, La, Pd, Pt, Mm and Re, where Mm is mischmetal and Re is a rare-earth metal obtained by mechanochemical processing of polycrystalline hydrides, reaction milling, gas-phase condensation, laser (plasma) processing or using sol-gel technology (US Patent 6573836, IPC ⁷ С01В 003/02, С01 B 003/04; C01B 003/08. Method for producing gaseous hydrogen by chemical reaction of metals or metal hydrides resulting to intense mechanical deformations / Schulz R., Huot J., Liang G., Boily S. // 06/03/2003) . It was shown that the high-energy effect leading to the production of nanosized MgH ₂ (average particle diameter ~ 12 nm, specific surface area ~ 9.9 m ² / g) or its composite with Ca, Li, or LiAlH ₄ improves the kinetics of hydrolysis (Huot J., Liang G., Schulz R. Magnesium-based nanocomposites chemical hydrides. // J. Alloys and Compounds. 2003. V.353. P. L12-L15.). The addition of 1% hydrochloric acid also has a beneficial effect on the kinetics of hydrogen evolution, since the resulting magnesium chloride is highly soluble in water.

The disadvantages of this technical solution are the high energy consumption (up to 1.5 kW / g) to obtain a nanocomposite and high reactivity of a substance in a metastable state, preventing its long-term storage until use. In addition, when using dilute hydrochloric acid, hydrogen chloride is inevitable in the generated hydrogen.

In terms of the composition for generating hydrogen, the closest in technical essence and the largest number of essential features to the claimed solution is a composition comprising hydrides (borohydrides, aluminum hydrides or a mixture thereof) of alkaline and alkaline-earth (Li, Na, K, Rb, Cs, Mg, Be, Ca, Al or a mixture thereof) metals or mixtures thereof, 0.1 ÷ 15 wt.% Catalyst (Ru or its compounds, cobalt, nickel or tungsten carbides or their mixture or cobalt, nickel, ruthenium and platinum acetylacetonates) and ≥ 0.5 wt.% Polymer agent (cellulosic or polyester fibers, polyac Rylamide or a mixture thereof) adopted as a prototype (International application 2005005311 WO, MKI C01B 3/00. Hydrogen generator / Salinas C., Cisar A., Clarke E., Murphy O.J., Fiebig B. // 01.20.2005 )

The disadvantages of the technical solutions of the prototype are:

- the need to use a large amount of catalyst (up to 15%);

- unproductive consumption of the catalyst due to its interaction with acids;

- the inapplicability of certain acids due to their volatility or insolubility of the salts formed;

- the interaction of organic and inorganic acids in the case of a mixture thereof;

- the impossibility of generating high-purity hydrogen when using most organic and inorganic acids, organic solvents and liquid ammonia due to their volatility.

The amount of catalyst according to the invention is quite large, and the invariability of the catalyst itself after the process has not been proved, i.e. there is no reason to call it a catalyst. Due to the high vapor pressure and the possibility of getting into hydrogen, it is doubtful whether to use organic solvents in the process. In addition, not all of these mineral and carboxylic acids are applicable in the hydrolysis of magnesium, calcium, and beryllium hydrides due to the poor solubility (e.g. phosphoric acid) of their salts or because of their volatility (hydrochloric, nitric, acetic, propionic, butyric acids) .

The closest in technical essence to the present invention in terms of the method of preparing the composition is a method of preparing a composition for generating hydrogen, selected as a prototype, comprising dissolving or suspending the hydride and catalyst in a non-reactive hydride, such as an organic solvent (tetrahydrofuran, ethylene glycol ethers, anhydrous ammonia, substituted amines, pyridine or a mixture thereof), evaporation of the solvent and removal of the composition in solid form (International application 2005005311 WO, MKI C01B 3/00. Hydroge n generator / Salinas C., Cisar A., Clarke E., Murphy O.J., Fiebig B. // 01.20.2005).

The disadvantages of this prototype method are the insolubility of most of these hydrides and catalysts in the listed solvents, the interaction of hydrides and catalysts with solvents during dissolution and the decomposition of hydride during evaporation of the solvent, which makes this method unrealizable.

The closest in technical essence to the present invention in terms of a hydrogen generator is a known hydrogen generator, including a reaction vessel for storing the composition, a vessel with an aqueous solution connected to the reaction vessel, and means for controlling the rate of supply of the aqueous solution. An aqueous or organic solvent containing mineral or organic acid (or a mixture thereof) and an antifoam agent (surfactants of various nature, glycol, polyol, or theirs) are supplied to a composition formed in the form of tablets or granules, or to a composition fixed on a porous carrier. mixture). The controlled evolution of hydrogen becomes possible as a result of the use of passive (selection of the concentration of catalyst in the composition) and active (dosed supply of solvent at a high concentration of catalyst) control (International application 2005005311 WO, MKI C01B 3/00. Hydrogen generator / Salinas C., Cisar A. , Clarke E., Murphy OJ, Fiebig B. // 20.01.2005).

The generator is not safe and convenient to use, because:

but. contains solid (molded mixture of hydride, catalyst and a binder or porous carrier) and liquid (solvent, antifoam, acid) components in one device, which does not exclude the possibility of unauthorized operation;

b. not adjustable because passive (concentration of the catalyst) regulation is possible only when preparing the composition, active (by dosing the solvent) is only possible with a high concentration of catalyst;

at. not universal, since the rate of hydrogen evolution can be provided only during the preparation of the composition, but not during its operation.

The objective of the present invention is to develop a convenient to use, safe to handle composition for controlled controlled autonomous and portable generation of high-purity hydrogen, transportable and suitable for use in the field, its preparation method and apparatus for generating hydrogen.

In the part of the composition for generating hydrogen, the task is solved in that the composition includes magnesium hydride, a binder, sulfuric acid and a sulfuric acid sorbent that does not interact with sulfuric acid, as a sulfuric acid sorbent it contains a material selected from the group consisting of silicon dioxide aerogels titanium dioxide, zinc oxide, aluminum oxide, and as a binder contains a substance selected from the group: fluoroplast, polyethylene, polypropylene, in the following ratio, wt.%:

magnesium hydride 10-22.8 binder 2.0-10.0 sulphuric acid 60-83.0 sulfuric acid sorbent 5.0-10.0

with a molar ratio of magnesium hydride to sulfuric acid equal to 1.

Magnesium hydride can be obtained by any of the possible methods and used in the form of powder or granules, tablets, pellets, formed from a mixture of magnesium hydride and a binder.

In terms of the method of preparing the composition for generating hydrogen, the problem is solved in that the method of preparing the composition for producing hydrogen includes sorption of sulfuric acid with a sorbent and the formation of magnesium hydride with a binder in the form of tablets, pellets or granules. In this method, as a sorbent of sulfuric acid, a material selected from the group consisting of aerogels of silicon dioxide, titanium dioxide, zinc oxide, aluminum oxide is used, and as a binder, a substance selected from the group comprising fluoroplastic, polyethylene, polypropylene.

In the part of the apparatus for generating hydrogen, the problem is solved in that the apparatus for generating hydrogen includes a reactor made in the form of interconnected vessels and containing the composition for producing hydrogen, and a water metering device, said reactor having a feedback reducer for producing hydrogen and in the form of a U-shaped vessel containing the specified composition. Schematically, the apparatus for generating hydrogen is shown in Fig.3. The device consists of two (in the diagram - left 1 and right) communicating vessels. The vessel 1 has a valve for the release of hydrogen with a constant flow rate 2 and a movable perforated container 4 for the composition for producing hydrogen (granules of magnesium hydride with a binder). The right vessel is equipped with a dosed water supply device 3. Hydrogen evolution is controlled in two ways: dosed water supply to the specified composition through the device 3 and controlled supply of magnesium hydride in the molded form by lowering or raising the movable tank 4. The supply of reactor 1 with a feedback reducer 2 allows achieve the specified conditions for the release of hydrogen and, if not observed, build up pressure in the reactor. The resulting hydrogen pressure in the reactor causes the liquid to be squeezed into the second elbow in the U-shaped vessel, the acid solution is not in contact with the magnesium hydride composition in the perforated container 4 with the binder, and thus the hydrogen evolution ceases.

The present invention is illustrated by drawings:

figure 1, which shows the curves of hydrogen evolution at a metered supply of water, when the required amount of water is introduced once (curve 1), at a speed of 1 ml / min (curve 2) and 0.2 ml / min, (curve 3) with the ratio magnesium hydride to sulfuric acid, equal to 1: 1 mol. and 1: 0.5 mol. (curve 4);

figure 2, which shows the dependence of the rate of hydrogen evolution on the mass of magnesium hydride in the form of granules formed from a mixture of magnesium hydride with 10 wt.% airgel of silicon dioxide;

figure 3, which schematically shows an apparatus for generating hydrogen, including a reactor 1, made in the form of communicating vessels and equipped with a valve for the release of hydrogen with a constant flow rate 2, a metering device for water 3 and a movable perforated container for granules of magnesium hydride with a binder 4.

Regulation of hydrogen evolution is carried out in two ways: dosed supply of water to the specified composition and controlled supply of magnesium hydride in a molded form.

At a dosed water supply, the regulated evolution of hydrogen is achieved due to the limited solubility of the formed magnesium sulfate (44.5 g per 100 g of water at 20 ° C). The regulation of hydrogen generation by supplying magnesium hydride molded with a binder is associated with a directly proportional dependence of the rate of hydrogen evolution on the amount of magnesium hydride in contact with the acid solution (Fig. 2) and the hydrophobicity of the binder, as a result of which the aqueous acid solution does not linger on the granules, containing magnesium hydride, after the termination of the contact of the granules with an aqueous solution of acid. The rate of hydrogen evolution when using the specified composition and the specified apparatus for generating hydrogen is also achieved by using a reactor in the apparatus made in the form of a U-shaped vessel and equipped with a feedback reducer for the release of hydrogen. The supply of reactor 1 with a gearbox with feedback 2 allows you to achieve the specified conditions for the release of hydrogen and, if not observed, build up pressure in the reactor. The pressure of hydrogen obtained by introducing water or an acid solution in the reactor causes the liquid to be squeezed into the second elbow in the U-shaped vessel, the acid solution is not in contact with 4 tablets, pellets or granules molded from magnesium hydride with a binder in a perforated vessel, and thus stopping the evolution of hydrogen.

The claimed technical solution is illustrated by the following examples of specific use.

Experiment 1. In a reaction vessel equipped with two valves, 0.207 ml of concentrated sulfuric acid with a density of 1.84 g / cm ³ (96 wt.%, Weight 0.366 g, 3.731 mmol) is added, 0.100 g of aerosil is added, thoroughly mixed and 0.132 g is added. magnesium hydride with a purity of 74.3 wt.% (3,731 mmol) with 0.03 g of a binder (polyethylene). The vessel is closed with a rubber punctured stopper and connected through a tap to a 250 cm ³ burette, purged with hydrogen, after which the stopper is pierced with a syringe filled with 5 ml of distilled water, 0.5 ml of water is introduced and the volume of hydrogen released is recorded every 0.5 min by adding every 2 min 0.5 ml of water. For 8 minutes at a temperature of 21 ° C, 180 cm ³ (7.462 mmol) of hydrogen or 2 mol of H ₂ / mol of MgH _{2 was released} (Fig. 1, curve 1).

Experiment 2. Under the conditions of experiment 1, 0.25 ml of water is introduced and the volume of hydrogen evolved is recorded every 0.5 minutes, adding 0.25 ml of water every 2 minutes. For 14.5 minutes at a temperature of 21 ° C, 180 cm ³ (7.462 mmol) of hydrogen or 2 mol of H ₂ / mol of MgH _{2 was released} (Fig. 1, curve 2).

Experiment 3. Into a reaction vessel equipped with two valves, 1 g of a composition comprising 0.83 g of sulfuric acid with a concentration of 45.4 wt.% (3.845 mmol) is introduced, 0.05 g of silica airgel is added, mix thoroughly and a tablet is introduced formed from 0.100 g of magnesium hydride (3.845 mmol) and 0.020 g of fluoroplastic. The ratio of the components of the composition is 10 wt.% MgH ₂ , 2 wt.% A binder (fluoroplast), 83 wt.% Sulfuric acid and 5 wt.% Sorbent (silicon dioxide). The vessel is closed with a rubber punctured stopper and connected through a tap to a burette with a volume of 500 cm ³ , purged with hydrogen, then the stopper is pierced with a syringe filled with 5 ml of distilled water, water is introduced and the volume of hydrogen evolved is recorded every 0.5 min. Over 5 minutes at a temperature of 22 ° C, 186.2 cm ^{3 of} hydrogen or 7.69 mmol were released.

Experience 4. In a reaction vessel equipped with two valves, inject 1 g of a composition comprising 0.600 g of sulfuric acid with a density of 1.84 g / cm ³ (96 wt.%, 5.88 mmol), add 0.100 g of titanium dioxide airgel, mix thoroughly and administering a tablet formed from 0.228 g of magnesium hydride with a purity of 67 wt.% (5.88 mmol) and 0.072 g of polyethylene. The vessel is closed with a rubber punctured stopper and connected through a tap to a burette with a volume of 500 cm ³ , purged with hydrogen, then the stopper is pierced with a syringe filled with 5 ml of distilled water, water is introduced and the volume of hydrogen evolved is recorded every 0.5 min. For 7 minutes at a temperature of 22 ° C, 284.5 cm ^{3 of} hydrogen or 11.75 mmol were released.

Test 5. 1 g of a composition comprising 0.700 g of sulfuric acid (100 wt%, 7.143 mmol) is introduced into a reaction vessel equipped with two valves, 0.050 g of zinc oxide airgel is added, the mixture is thoroughly mixed and a tablet formed of 0.186 g of magnesium hydride is introduced. purity of 99.5 wt.% (7.143 mmol) and 0.064 g of polypropylene. The vessel is closed with a rubber punctured stopper and connected through a tap to a burette with a volume of 500 cm ³ , purged with hydrogen, then the stopper is pierced with a syringe filled with 5 ml of distilled water, water is introduced and the volume of hydrogen evolved is recorded every 0.5 min. For 7 minutes, at a temperature of 22 ° C, 345.8 cm ^{3 of} hydrogen or 14.27 mmol were released.

Experiment 6. 0.700 g of sulfuric acid (7.143 mmol) is introduced into the reaction vessel (FIG. 3), 0.070 g of aluminum oxide airgel is added and mixed thoroughly. A tablet formed of 0.186 g of magnesium hydride (7.143 mmol) and 0.044 g of fluoroplastic is introduced into a movable perforated container 4. The vessel is closed with a rubber punctured stopper and connected through a tap to a burette with a volume of 500 cm ³ , purged with hydrogen, after which the stopper is pierced with a syringe filled with 5 ml of distilled water, 1 ml of water is introduced and the volume of hydrogen released is recorded every 0.5 min. After 2 minutes, the selection of hydrogen is stopped (valve 2 is shut off). The liquid is squeezed into the second elbow and removed from the perforated container 4. After 3 minutes, valve 2 is opened, the liquid moistens the tablet, but hydrogen is practically not released. Another 0.25 ml of water is introduced, the volume of hydrogen evolved is recorded by adding 0.25 ml of water every 2 minutes. For 30 minutes at a temperature of 22 ° C, 345.8 cm ^{3 of} hydrogen or 14.27 mmol were released.

Experiment 7. 0.700 g of sulfuric acid (7.143 mmol) is introduced into the reaction vessel (FIG. 3), 0.070 g of aluminum oxide airgel is added and mixed thoroughly. A tablet formed from 0.186 g of magnesium hydride (7.143 mmol) and 0.044 polypropylene is introduced into a movable perforated container 4. The vessel is purged with hydrogen, after which 1 ml of water is introduced and the volume of hydrogen generated is recorded every 0.5 minutes. After 2 minutes, the selection of hydrogen is stopped (valve 2 is shut off). The liquid is squeezed into the second elbow and removed from the perforated container 4. After 3 minutes, valve 2 is opened, the liquid moistens the tablet, but hydrogen is practically not released. Another 0.25 ml of water is introduced, the volume of hydrogen evolved is recorded by adding 0.25 ml of water every 2 minutes. For 30 minutes at a temperature of 22 ° C, 345.8 cm ^{3 of} hydrogen or 14.27 mmol were released.

Claims (3)

1. A composition for producing hydrogen, comprising magnesium hydride, a binder, sulfuric acid and a sulfuric acid sorbent that does not interact with sulfuric acid, as a sulfuric acid sorbent, it contains a material selected from the group consisting of silicon dioxide, titanium dioxide, zinc oxide aerogels, aluminum oxide, and as a binder it contains a substance selected from the group: fluoroplastic, polyethylene, polypropylene in the following ratio of components, wt.%:
magnesium hydride 10-22.8 binder 2.0-10.0 sulphuric acid 60-83.0 sulfuric acid sorbent 5.0-10.0
with a molar ratio of magnesium hydride to sulfuric acid equal to 1. 2. A method of preparing a composition for producing hydrogen, comprising sorption of sulfuric acid by a sorbent and molding magnesium hydride with a binder in the form of tablets, pellets or granules, characterized in that as the sulfuric acid sorbent a material selected from the group consisting of silicon dioxide, dioxide aerogels is used titanium, zinc oxide, alumina, and as a binder, a substance selected from the group comprising fluoroplast, polyethylene, polypropylene. 3. Apparatus for generating hydrogen, including a reactor made in the form of communicating vessels, containing a composition for producing hydrogen, a water dosing device, characterized in that said reactor is equipped with a feedback reducer for hydrogen release, made in the form of a U-shaped vessel containing the composition according to claim 1.

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