RU2410325C2 - Aluminium-based composite material for producing hydrogen and preparation method thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: aluminium-based composite material for producing hydrogen contains aluminium or alloy thereof, which contains not less than 85% aluminium in form of granules, powder or wastes from aluminium mechanical processing: filings, shavings in amount of not less than 90%, anhydrous hydroxide of an alkali metal which decomposes an oxide film when reacting with water, up to 6% copper, silicon, magnesium additives, so that this composite material contains a total of up to 10% of these additives together with the alkali. The components are mixed in a mixer to obtain the composite material. The obtained mixture is blind pressed in a rigid container at pressure not lower than 650-700 MPa using a die which simultaneously rotates and moves to and from.

EFFECT: easy preparation of composite material.

2 cl

Description

The invention relates to the fields of energy and ecology. According to this invention, an aluminum-based composite is prepared for producing hydrogen by reaction with water. Moreover, the resulting hydrogen is used in various sectors of the economy, including transport, as an alternative fuel. A known method for the production of hydrogen using energy storage substances (EAS), emitting energy during chemical interaction with water [Warsaw I. Energy storage substances and their use. - Kiev: Naukova Dumka, 1980. - S.79-105 p.].

The closest analogue of the invention to paragraph 1 of an aluminum-based composite is the invention “Method for the production of hydrogen”. / Bulashevich E.A. et al. SU 111165, IPC С01В 3/08, published on January 1, 1957. It uses a mixture of aluminum, alkali and water to produce hydrogen. However, when using these components, this method has an insufficient reaction rate, moreover, the method does not imply use on an industrial scale, since the reaction is carried out in a flask. For the method according to paragraph 2, the prototype is the invention "Alloy based on aluminum to generate hydrogen. The method of its production and hydrogen generator ”/ B.C. Tereshchuk. - RF patent №2253606, IPC С01В 3/08. Publ. 2005, Bull. No. 16.]. The method consists in producing hydrogen from an aluminum alloy, anhydrous alkali metal hydroxide and copper in a gas generator. The disadvantages of this invention is the need to create a special protective atmosphere, the complexity of the process and high energy consumption.

The objective of the present invention is to develop the optimal composite to accelerate the reaction and a simpler, cheaper way to produce hydrogen, including on an industrial scale, as well as expanding the arsenal of tools.

SUMMARY OF THE INVENTION (SUMMARY OF THE INVENTION)

The chemical composition of the proposed composite is similar to the prototype alloy [RF Patent No. 2253606] and the mixture SU 111165.

However, in the present invention, unlike SU 111165, additives of copper, silicon and magnesium are used to improve the reaction rate. Thus, the addition of copper creates a galvanic pair with aluminum, as a result of which an electric potential arises and the reaction rate increases. Magnesium and silicon additives also accelerate the process as a result of foci of corrosion of the composite. When foci of corrosion occur inside the composite, they begin to “tear” the composite from the inside, which further increases the reaction area. In addition, the optimal percentage of reaction components was selected. All this in total increases the reaction yield,

In contrast to the method described in RF patent No. 2253606, an advantage of the present invention is that mechanical waste is used in the form of chips, powder, sawdust from aluminum of any grade or its alloys, preferably with an A1 content of at least 85% (meaning silumin, AMG, etc.) in a weight quantity in composite A1 or its alloy is not less than 90%, which reduces the cost of such a material.

The second advantage, in contrast to the prototype, is that the composite is made not by melting in an induction furnace, but by the method of press pressing with preliminary mixing of its components, which greatly simplifies the manufacture of such material compared to the melting process provided for in the prototype.

The implementation of the invention

An aluminum-based composite is used for the production of hydrogen, including aluminum or its alloy containing at least 85% aluminum, in the form of granules, powder or mechanical waste of any type of aluminum: sawdust, shavings in a weight quantity of at least 90%, dehydrated hydroxide alkali metal, which destroys the oxide film when interacting with water, as well as additives of copper, silicon, magnesium up to 6%, so that this composite contains these additives together with alkali in the amount of up to 10%. The composite forms a mixture intended for subsequent compartmentalization.

A method of manufacturing a composite is as follows.

The components of the composite are weighed in the above ratio. For example, aluminum is mixed in the form of mechanical waste of any type of aluminum: sawdust in a weight quantity of 91% in a mixer with dehydrated alkali metal hydroxide, for example NaOH, which destroys the oxide film when interacting with water, in a weight quantity of 6% and with the addition of copper, magnesium and silicon in a weight amount of 3%. The mixture of aluminum or its alloy with dry alkali and additives is carried out in a mixer. The resulting mixture is pressed by pressing in a rigid container at a pressure of at least 650 ÷ 700 MPa with a punch that simultaneously performs translational and rotational motion.

To reduce the pressure during pressing in order to achieve a compaction coefficient of 100%, the stamp can be equipped with a heating device with the possibility of heating 250 ÷ 650 ° C.

These differences from the prototypes provide the following advantages:

1. Copper, silicon and magnesium additives are added to the composition to improve the reaction rate. Thus, the addition of copper creates a galvanic pair with aluminum, as a result of which an electric potential arises and the reaction rate increases. Additives of magnesium and silicon also accelerate the process as a result of foci of corrosion of the composite. When foci of corrosion occur inside the composite, they begin to “tear” the composite from the inside, which further increases the reaction area. In addition, the optimal percentage of reaction components was selected. All this in total increases the yield of the reaction.

2. Various industrial wastes are used in the processing of A1 and its alloys, which significantly reduces the cost of manufacturing composites for hydrogen production.

3. It is not required to create a special protective atmosphere, which also reduces the cost of the manufacturing process of composites.

4. This method allows you to mix any components and in any combination in percentage terms, because during smelting, this is a serious obstacle preventing, for example, making alloy A1 with sodium, which in metallurgy belongs to the class of immiscible components (NC).

Thus, the claimed method and composition can be successfully implemented day hydrogen generation.

Claims (2)

1. An aluminum-based composite for the production of hydrogen, including aluminum or its alloy containing at least 85% aluminum, in the form of granules, powder or waste from machining aluminum: sawdust, shavings, in a weight quantity of at least 90%, anhydrous alkali metal hydroxide , destroying the oxide film when interacting with water, additives of copper, silicon, magnesium up to 6%, so that this composite contains these additives together with alkali in the amount of up to 10%. 2. The method of producing a composite according to claim 1 for the production of hydrogen, comprising mixing aluminum or its alloy containing at least 85% aluminum, in the form of granules, powder or waste from machining aluminum: sawdust, shavings, in a weight amount of at least 90%, with dehydrated alkali metal hydroxide, which destroys the oxide film when interacting with water, and with additives of copper, silicon, magnesium up to 6%, so that this composite contains these additives together with alkali in the amount of up to 10%, in a mixer, the resulting mixture is pressed by dull pressing in a rigid container at a pressure of at least 650-700 MPa with a punch that performs both translational and rotational movements.