Aluminum-based reagent for generation of hydrogen and method for producing said reagent

Abstract

The invention relates to a reagent developed for use in the generation of hydrogen gas, said reagent releasing the hydrogen gas in a controlled manner upon contact with water or a similar medium, said reagent being obtained via a mechano-chemical method, and said reagent comprising a mixture of aluminum, sodium stannate (Na2SnO3) and / or potassium stannate (K2SnO3), and an inorganic hydroxide.

Description

[0001] DESCRIPTION

[0002] ALUMINUM-BASED REAGENT FOR GENERATION OF HYDROGEN AND METHOD FOR PRODUCING SAID REAGENT

[0003] TECHNICAL FIELD

[0004] The present invention relates to an aluminum-based reagent developed for use in the generation of hydrogen gas, said reagent releasing the hydrogen gas in a controlled manner upon contact with water or a similar medium.

[0005] STATE OF THE ART

[0006] The hydrogen gas is considered as one of the future energy sources in terms of high energy density and environmental sustainability. Today, hydrogen has a wide field of use including the energy generation, industrial processes, and fuel cells. The methods commonly employed for generating hydrogen include biomass gasification, natural gas reformation, coal gasification, electrolysis, and photobiological transformation. However, most of these methods have various disadvantages like high energy consumption, costly equipment requirements, and adverse environmental impacts. In particular, the methods based on the fossil fuels generate an extra environmental load by increasing the carbon emissions.

[0007] Although biomass gasification enables the generation of hydrogen from the organic wastes, the problems such as complex process equipment and low efficiency are faced. While natural gas reformation is one of the most common methods in the generation of hydrogen, it is an energy-intensive process due to the its requirement for high temperature and pressure. Electrolysis is a method effective for obtaining pure hydrogen; however, it is limited in economical terms because of high electricity consumption. The innovative methods like photobiological transformation, despite being promising from the perspective of sustainability, have not yet attained the use on the commercial scale. All these methods indicate that it is necessary to improve the hydrogen generation in terms of cost effectiveness and environmental sustainability.

[0008] Not only generating hydrogen, but also transporting and storing the same involve significant technical and logistic difficulties. These difficulties are considered as one of the greatest obstacles before the extension of the use of hydrogen. Hydrogen is a low-density gas and its storage or transport in great volumes need special systems. This requires the compression ofhydrogen to be transported in high-pressure tanks or the liquefaction of the same (at extremely low temperatures such as -253°C) to be stored in cryogenic tanks. Both methods consume significant amounts of energy and have high cost. Particularly, the energy required to transport hydrogen during the liquefaction process may reach the levels as high as 30-40% of the energy content of the hydrogen being transported.

[0009] Another major issue encountered in the transport of hydrogen is safety. Hydrogen is a very flammable gas and carries the serious risk of explosion in case of leakage, due its low ignition energy. The expansion ratio and the invisible flames of the gas make the containment and response processes even more complicated. These characteristics necessitate high safety standards for the hydrogen transport infrastructure, which increases the costs even further.

[0010] The installation and maintenance of the special equipment used for the transport and the storage is another factor limiting the use of hydrogen. Transport of hydrogen via the pipelines is an expensive and long-term process due to the technical difficulties like the weakening of the metallic pipes by the hydrogen molecules (hydrogen embrittlement). T ransport of hydrogen in the tubes or tanks as an alternative provides the ability to transport only limited amounts of hydrogen, which in turn leads to inefficiencies especially in the large-scale practices.

[0011] For all these reasons, generating hydrogen directly at a place of use, instead of transporting it from a place of generation to a place of use, provides great advantages. On-site generation eliminates the problems of energy, cost, and safety associated with the transport and the storage of hydrogen. Moreover, this method increases the overall process efficiency by preventing the energy loss likely to occur during the transport of hydrogen. On-site generation of hydrogen is preferred more especially for remote areas, portable energy sources, emergencies, and small-scale applications. This method not only enables hydrogen to be used in a rapid and safe manner, but also minimizes the possible environmental risks during the transport. Consumption of hydrogen at a place where it is generated reduces the infrastructure investments and logistic costs, thereby enhancing the economic sustainability of the technology.

[0012] In terms of the use of hydrogen at the place of use as well as the generation of hydrogen at low cost, a reaction between aluminum and water stands out as a good alternative for the hydrogen generation. In this chemical reaction, hydrogen gas and aluminum oxide or aluminum hydroxide form as a result of the interaction of aluminum with water. Owing to the high reactivity of aluminum, this process may take place even at temperature and, this in turn,minimizes the energy consumption. However, the effectiveness of this method is severely limited due to the passivation layer formed on the surface of aluminum.

[0013] The passivation layer is a thin layer of aluminum oxide (AI2O3), which forms as a result of the reaction of aluminum with oxygen or humidity in the air and which coats the surface. This layer prevents the progress of the reaction by protecting the surface of aluminum from the chemical attack of the water. Lowering the reaction rate and reducing the efficiency, this layer is one of the greatest technical barriers before the use of aluminum for the generation of hydrogen. Various methods are usually employed to eliminate the passivation layer. These include processing aluminum at elevated temperature, treating aluminum with strong alkaline solutions, or adding special catalysts. On the other hand, these methods may render the process more complicated and costly, thus eliminating the economic advantage.

[0014] Another disadvantage of the passivation layer on the surface of aluminum is that it delays the initiation stage of the reaction and renders the generation of hydrogen uncontrollable. This layer, by acting not only as a chemical barrier but also a physical barrier, restricts the access of the water to the surface of aluminum. The thickness and the strength of the passivation layer may vary depending on the purity of aluminum, the method of generation, and the environmental conditions. This complicates the standardization and the scaling of the processes.

[0015] In addition, the alkaline solutions used to decrease the effect of the passivation layer bring about some challenges in environmental terms. The use of strong bases entails extra costs and liabilities from the points of view of waste management and environmental safety. On the other hand, although this layer may be partly overcome by the use of the catalysts, the production and reuse of the catalysts is another limiting factor for the commercial practices.

[0016] EP1301433A1 relates to the generation of the hydrogen gas at the ambient temperature by using aluminum, water, and sodium hydroxide (NaOH) catalyst, and to a device, which realizes this process in a safe and practical manner. This patent document aims, in particular, at effectively removing the protective oxide layer on aluminum and achieving the ability to continuously control the reaction, in the process of hydrogen generation. The device disclosed in the patent document consists of a dilatable chamber for regulating the reaction, a pressure control mechanism, a timer, and the fuel elements.

[0017] US2009252671A1 relates to a system generating the hydrogen gas by using aluminum, alkali metal oxide (e.g., NaOH), and water. The object of the document is to provide an alternativefuel source against the energy crisis and the carbon emissions, by proposing a solution where hydrogen may be generated in a safe, economical, and on-demand manner. This object is achieved by combining aluminum, water, and NaOH in a controlled manner in a reactor, based on the principle of limited reactants.

[0018] Consequently, it is necessary to develop new methods, which will deactivate the passivation layer or minimize the adverse effects of said layer in order to render the reaction between aluminum and water more efficient and economical in the hydrogen generation and via which the generated hydrogen is able to be stored in a state ready for use. The existing technologies lack a sufficiently effective and practical solution for preventing or overcoming the passivation layer and this limits the efficiency and the cost effectiveness of the hydrogen generation processes. Therefore, it is an urgent need to develop the innovative methods that optimize the physical and chemical properties of aluminum, prevent the passivation, or reduce the impacts of this barrier.

[0019] OBJECT OF THE INVENTION

[0020] An object of the invention is to effectively eliminate the problem of passivation layer encountered in the generation of hydrogen via the reaction between aluminum and water, thereby improving the efficiency and the rate of said reaction.

[0021] Another object of the invention is to develop a reagent, which prevents the formation of the passivation layer on the surface of aluminum and is thus able to readily react with water.

[0022] Another object of the invention is to develop a reagent, which releases hydrogen by reacting with water at atmospheric pressure and room temperature without requiring high temperature and / or pressure.

[0023] Another object of the invention is to develop a reagent with a homogeneous structure.

[0024] Another object of the invention is to develop a reagent with a pellet structure, which is ready for reaction with water and enables the initiation of the hydrogen generation as a result of the contact thereof with water.

[0025] Another object of the invention is to develop a reagent, which, owing to its pellet structure, makes it possible for the reaction with water to take place at stoichiometric ratios.DETAILED DESCRIPTION OF THE INVENTION

[0026] The invention relates to a reagent developed for use in the generation of hydrogen gas, wherein said reagent comprises aluminum, an inorganic hydroxide, and sodium stannate (Na2SnO3) and / or potassium stannate (K2SnO3) and said reagent releases the hydrogen gas in a controlled manner upon contact with water or a similar medium.

[0027] The reagent according to the invention comprises a mixture of 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnO3) and / or potassium stannate (K2SnO3), and 10-20% by mass an inorganic hydroxide. In a preferred embodiment of the invention, said mixture is a mixture in pellet form. In a preferred embodiment, the reagent is a reagent comprising said mixture at a ratio of 70-100% by mass.

[0028] In a preferred embodiment of the invention, said inorganic hydroxide is sodium hydroxide (NaOH).

[0029] In a preferred embodiment of the invention, said mixture of 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnO3) and / or potassium stannate (K2SnO3), and 10-20% by mass an inorganic hydroxide is a mixture, which is prepared via mechano-chemical method, i.e., a mixture, which is mechano-chemically activated. In a preferred embodiment, said mixture is prepared by grinding the ingredients contained in said mixture in a ball mill. Said grinding process is performed preferably under the cryogenic conditions. During the grinding process in the ball mill, the size of the aluminum powders is reduced and the surface area of the same is increased, thereby enabling aluminum to become more available for the chemical reactions. The small particle size provides wider active surfaces that increase the reaction rate and the effectiveness. The mechanical grinding process leads to disruptions in the crystalline structure of the aluminum powders and these micro- structural changes enable the formation of more reactive surfaces, thus increasing the chemical reactivity of aluminum. Sodium hydroxide (NaOH) in the mixture dissolves the natural oxide layer on the surface of aluminum to enable the active aluminum atoms to become exposed, wherein this interaction increases the rate of the reactions between aluminum and sodium hydroxide (NaOH) and facilitates the chemical conversions.

[0030] Upon the contact of aluminum with water, the following reaction takes place and the hydrogen gas is released:

[0031] 2AI + 6H2O 2AI(OH)3+ 3H2Under normal conditions, the reaction will not take place during the contact of aluminum with water at neutral pH, unless the existing passivation layer is dissolved. Passivation refers to the formation of a thin protective oxide layer (generally AI2O3) on the surface of the reactive metals like aluminum. This layer substantially prevents aluminum from undergoing further oxidation or from undergoing other reactions. Despite being rather thin, more specifically, having a thickness of only a few nanometers, this layer is very strong and prevents the direct contact of aluminum with water or other chemicals. The reaction progresses and the hydrogen gas forms only when the passivation layer is abraded mechanically or is dissolved via chemical activation. Within the scope of the invention, the passivation layer is enabled to be effectively abraded via a combination of mechanical and chemical methods, wherein it is desirable to enable the generation of the hydrogen gas to continue with high efficiency, and for this purpose, sodium stannate (Na2SnO3) and / or potassium stannate (I^SnOs) and sodium hydroxide (NaOH) are used.

[0032] Sodium hydroxide (NaOH) is included in the mixture mainly for the purposes of generating a basic medium and initiating the reaction of aluminum with water. It dissolves the layer of aluminum oxide (AI2O3) that naturally forms on the surface of aluminum and aluminum becomes active owing to the dissolution of said layer. In a basic medium, aluminum rapidly reacts with water to generate the hydrogen gas (H2).

[0033] Sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs) is / are included in the mixture for the purposes of supporting the degradation of the passivation layer, increasing the rate of hydrogen generation, and reducing the side reactions. Sodium stannate (Na2SnOs) and / or potassium stannate (t^SnCh) enable / s the oxide layer on the surface of aluminum to weaken and the surface of aluminum to remain continuously available for the reaction. In the experiments conducted within the scope of the invention, it was determined that sodium stannate (Na2SnOs) and / or potassium stannate (t^SnCh) ions catalyze the reactions on the surface of aluminum and increase the rate of hydrogen generation in the reaction of aluminum with water. Moreover, sodium stannate (Na2SnOs) and / or potassium stannate (t^SnCh) prevent / s the formation of the undesired side products that are possible to be generated during the reaction and enable / s the reaction to progress in a more controlled manner.

[0034] It was observed that sodium stannate (Na2SnOs) and / or potassium stannate (t^SnCh) and sodium hydroxide (NaOH) mixed with aluminum produce a synergistic action whereby sodium hydroxide (NaOH) increases the alkalinity of the medium while sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs) provide / s a catalytic effect, as a result of which thereaction becomes faster and more efficient, the generation rate of the hydrogen gas increases, and the reaction of aluminum with water is facilitated to enable the process to be completed in a shorter time.

[0035] The reagent according to the invention is a reagent, which comprises a mixture of 70-85% by mass aluminum powder, 10-20% by mass an inorganic hydroxide, and 5-10% by mass sodium stannate (Na2SnO3) and / or potassium stannate (I^SnOs). These are not ordinarily selected percentages; they are the ratios at which a surprising effect is achieved where the generation of the hydrogen gas is enabled by maximizing the efficiency and the reaction rate, without posing a safety risk.

[0036] In case sodium hydroxide (NaOH) is used at a ratio greater than the one specified, the reaction becomes very fast and uncontrollable, which in turn leads to excessive heating and poses safety risks. Besides, the viscosity of the mixture increases and it becomes difficult to manage said mixture. On the other hand, when the amount of sodium hydroxide (NaOH) drops below the specified ratio, it is not possible to fully dissolve the passivation layer, the progress of the reaction becomes difficult, and the efficiency decreases.

[0037] It was observed that, in case sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs) is / are used at a ratio greater than the one specified, the reaction rate does not increase, and besides, side reactions are triggered. In case of using the same at a ratio lower than the one specified, it was observed that the desired efficiency increase is not realized and the continuity of the reaction is not possible to ensure.

[0038] In a preferred embodiment, the reagent according to the invention comprises

[0039] o 70-80% by mass of a mixture including

[0040] 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (t^SnCh), and 10-20% by mass an inorganic hydroxide, and

[0041] o 20-30% by mass of a mixture including

[0042] 30-50% by mass an alkali metal chloride and 50-70% by mass aluminum.

[0043] In a preferred embodiment of the invention, the mixture of 30-50% by mass an alkali metal chloride and 50-70% by mass aluminum is a mixture prepared via mechano-chemical method. In the preferred embodiment, said mixture is prepared by mechanically grinding aluminum and alkali metal chloride. In a preferred embodiment, said mixture is prepared by grinding in a ballmill the ingredients contained in said mixture. Said grinding process is preferably performed under the cryogenic conditions.

[0044] In a preferred embodiment, said alkali metal chloride is sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI). In said embodiment, sodium chloride (NaCI) or potassium chloride (KCI) or mixture of sodium chloride (NaCI) and potassium chloride (KCI) physically breaks the passive layer on the surface of aluminum during the process of mechanical grinding with aluminum, thereby increasing the reaction surface, and provides local passages, thereby facilitating the contact of the water molecules with aluminum and increasing the generation rate of the hydrogen gas.

[0045] In an embodiment where sodium chloride (NaCI) is used as the alkali metal chloride, a synergistic effect is produced between sodium chloride (NaCI) and sodium hydroxide (NaOH). While sodium hydroxide (NaOH) breaks down the passivation layer of aluminum, enables said passivation layer to be dissolved, and initiates the generation of the hydrogen gas, sodium chloride (NaCI) increases the ionic conductance, prevents the passivation, and accelerates the reaction kinetics. In this way, owing to said synergistic effect, the reaction is enabled to take place in a faster, more efficient, and continuous manner, wherein these two compounds, by complementing the effects of one another, provide a significant advantage in the process of generation of the hydrogen gas.

[0046] In a preferred embodiment of the invention,

[0047] o the mixture including 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (^SnCh), and 10-20% by mass an inorganic hydroxide, and

[0048] o the mixture including 30-50% by mass an alkali metal chloride and 50-70% by mass aluminum

[0049] are pelletized.

[0050] In a preferred embodiment of the invention, said pellet is a pellet with a two-layer structure. In said embodiment, one layer of the pellet contains the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI), while the other layer thereof contains the mixture of aluminum, sodium hydroxide (NaOH), and sodium stannate (Na2SnOs) and / or potassium stannate (K2SnO3).

[0051] In the preferred embodiment of the invention, said two-layer pellet is obtained by first casting the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixtureof sodium chloride (NaCI) and potassium chloride (KCI) in a mold, then casting on the former the mixture of aluminum, sodium hydroxide (NaOH), and sodium stannate (Na2SnOs) and / or potassium stannate (^SnCh), and pressing the same.

[0052] The reagent according to the invention is a reagent, which enables the generation of the hydrogen gas at a minimum efficiency of 90% when said reagent encounters water at a temperature of 25°C and at the atmospheric pressure.

[0053] The reagent in pellet form according to the invention is obtained by a method comprising the process steps of;

[0054] o grinding together aluminum powder, inorganic hydroxide, and sodium stannate (Na2SnOs) and / or potassium stannate (^SnOs) to obtain a homogeneous powder form via the mechano-chemical method,

[0055] o grinding the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI) via mechano-chemical method, i.e. , grinding said mixture mechanically, to obtain a powder mixture, and casting said powder mixture in a mold,

[0056] o casting the homogeneous mixture, which is obtained by grinding together aluminum powder, inorganic hydroxide, and sodium stannate (Na2SnOs) and / or potassium stannate (^SnOs), i.e., obtained via the mechano-chemical method, on the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI), and

[0057] o pressing the mixture inside the mold and obtaining a two-layer pellet.

[0058] In a preferred embodiment of the invention,

[0059] o after casting in a mold 20-30% by mass of a mixture including

[0060] 30-50% by mass an alkali metal chloride and 50-70% by mass aluminum, o 70-80% by mass of a mixture including

[0061] 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (^SnQj), and 10-20% by mass an inorganic hydroxide

[0062] is cast on the former and the mold is pressed.

[0063] In a preferred embodiment of the invention, the grinding process is performed under the cryogenic conditions to achieve homogeneous distribution and maximum reactivity.

Claims

CLAIMS1. A reagent developed for use in the generation of hydrogen gas, said reagent releasing the hydrogen gas upon contact with water, characterized in that said reagent comprises a mixture of 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (t^SnCh), and 10-20% by mass an inorganic hydroxide.

2. A reagent according to Claim 1 characterized in that said reagent comprises the mixture including 70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs), and 10-20% by mass an inorganic hydroxide, at a ratio of 70-100% by mass.

3. A reagent according to Claim 1 or 2 characterized in that said inorganic hydroxide is sodium hydroxide (NaOH).

4. A reagent according to Claim 3 characterized in that said inorganic hydroxide is sodium hydroxide (NaOH), which enables the formation of a basic medium, the dissolution of the aluminum oxide layer, and the initiation of the reaction of aluminum with water.

5. A reagent according to any one of the preceding claims characterized in that the mixture of aluminum, sodium hydroxide (NaOH), and sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs) is a mixture, which is prepared via mechanochemical method, i.e. , a mixture, which is mechano-chemically activated.

6. A reagent according to Claim 5 characterized in that aluminum, sodium hydroxide (NaOH), and sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs) are aluminum, sodium hydroxide (NaOH), and sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs), which are ground in a ball mill.

7. A reagent according to Claim 5 or 6 characterized in that the mixture of aluminum, sodium hydroxide (NaOH), and sodium stannate (Na2SnOs) and / or potassium stannate (K2SnOs) is a mixture, which is prepared via mechano-chemical method in a cryogenic medium.

8. A reagent according to any one of the preceding claims characterized in that said reagent comprises the mixture of alkali metal chloride and aluminum at a ratio of 20- 30% by mass.

9. A reagent according to Claim 8 characterized in that the mixture of alkali metal chloride and aluminum is a mixture of alkali metal chloride and aluminum prepared via mechano-chemical method.

10. A reagent according to Claim 8 or 9 characterized in that said reagent comprises ° 70-80% by mass of a mixture including70-85% by mass aluminum powder, 10-20% by mass an inorganic hydroxide, and 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (^SnCh), and° 20-30% by mass of a mixture including30-50% by mass an alkali metal chloride and 50-70% by mass aluminum.

11. A reagent according to any one of Claims 8-10 characterized in that alkali metal chloride is is sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI), which physically breaks the passive layer on the surface of aluminum during the process of mechanical grinding with aluminum, thereby increasing the reaction surface, and provides local passages, thereby facilitating the contact of the water molecules with aluminum and increasing the generation rate of the hydrogen gas.

12. A reagent according to any one of the preceding claims characterized in that the mixture of 70-85% by mass aluminum powder, 10-20% by mass an inorganic hydroxide, and 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (K2SnOs) is a mixture in pellet form.

13. A reagent according to Claim 12 characterized in that said pellet is a two-layer pellet, one layer of which contains the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) ora mixture of sodium chloride (NaCI) and potassium chloride (KCI) and the other layer of which contains the mixture of aluminum, sodium stannate (Na2SnOs) and / or potassium stannate (^Sn j), and sodium hydroxide (NaOH).

14. A reagent according to Claim 12 characterized in that said pellet is a pellet obtained by first casting the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI) in a mold, then casting on the former the mixture of aluminum, sodium stannate (Na2SnOs) and / or potassium stannate (^SnCh), and sodium hydroxide (NaOH), and pressing the same.

15. A method for producing a reagent in two-layer pellet form developed for use in the generation of hydrogen gas, said reagent releasing the hydrogen gas upon contact with water, characterized in that said method comprises the process steps ofo grinding together aluminum powder, inorganic hydroxide, and sodium stannate (Na2SnOs) and / or potassium stannate (I^SnOs) to obtain a homogeneous powder form via the mechano-chemical method,o grinding the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI) via mechano-chemical method, i.e. , grinding said mixture mechanically, to obtain a powder mixture, and casting said powder mixture in a mold, o casting the homogeneous mixture, which is obtained by grinding together aluminum powder, inorganic hydroxide, and sodium stannate (Na2SnOs) and / or potassium stannate (^SnCh), i.e., obtained via the mechano-chemical method, on the mixture of aluminum with sodium chloride (NaCI) or potassium chloride (KCI) or a mixture of sodium chloride (NaCI) and potassium chloride (KCI), ando pressing the mixture inside the mold and obtaining a two-layer pellet.

16. A reagent production method according to Claim 15 characterized in that said method comprises the process steps ofo after casting in a mold 20-30% by mass of a mixture including30-50% by mass an alkali metal chloride and 50-70% by mass aluminum,o casting on the former 70-80% by mass of a mixture including70-85% by mass aluminum powder, 5-10% by mass sodium stannate (Na2SnOs) and / or potassium stannate (^SnCh), and 10-20% by mass an inorganic hydroxide, andpressing the mold.

17. A reagent production method according to Claim 15 or 16 characterized in that the grinding process is performed under the cryogenic conditions.