SU681674A1 - Method of hydrogen production - Google Patents

Description

The invention relates to methods for producing hydrogen and may find application in processes using hydrogen for oxidation in internal combustion engines or in fuel cells.

There is a method of producing hydrogen by reacting water with an amalgam of aluminum or a metal selected from the group — beryllium, zirconium, manganese, titanium, chromium at elevated temperature [1].

The main disadvantage of this method is the low rate of hydrogen evolution and a long contact time.

Closest to the described invention in technical essence and the achieved result is a method of producing hydrogen by reacting water with metal alloys containing aluminum and gallium, indium and tin additives in an amount of 1-5 weight. % at a temperature of ~ 90 ° C [2].

The main disadvantage of this method is the relatively low rate of interaction of the alloys with water, component 0.1 l / g min, as well as the presence of expensive and rare metals as additives.

The aim of the invention is to increase the rate of interaction of water with the alloy.

The goal is achieved by the method of producing hydrogen by the interaction of water with metal alloys containing aluminum, in which alloys containing lithium, sodium or potassium and aluminides of an element standing in a series of voltages to the left of hydrogen are used.

In this case, as an aluminide of an element, a substance is taken from a grappa containing 10 Mg, B, Si, Ti. Cr, V, Kb, W, Zr, Hi, Μη, Sb, and Fe.

In addition, lithium, sodium or potassium and the aluminide of the element are taken in a weight ratio of 1–5: 5–20, 75–84, and 15 contains 10–40 weight. % aluminum.

This method allows to increase the rate of interaction of water with the alloy from 0.1 l / g min to 0.68-0.91 l / g min, that is, 7-20 9 times.

The above aluminides in powder form are fused at a temperature of 150-200 ° C with 1-5% lithium and 25 5-20% sodium or potassium without a protective atmosphere and flux with vigorous stirring. The resulting powder is pressed into specific forms and stored in sealed vessels or under a layer of inert 30 organic solvent.

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These alloys intensively, some with an explosion, interact with water, releasing hydrogen. Some aluminides containing boron, silicon, germanium, antimony, in addition to produce hydrogen up to 100 weight. %, respectively, boron hydrogen, silanes, germanic hydrogen, antimony hydrogen. Their content decreases when a maximum specified amount of sodium or potassium is introduced into the alloy.

In the process of interaction of the alloy with water, it heats up to several hundred degrees, which brings water to a boiling state. For this reason, the initial water temperature does not affect the rate of hydrogen evolution.

Example 1. In an arc furnace in an argon medium, 18 g of amorphous powdered boron is fused, wrapped in aluminum foil to a fine powder. In a porcelain crucible, 1 g of lithium metal is melted and 20 g of the diluted alloy is poured into it with vigorous stirring, then 2.5 g of sodium metal are introduced and the whole mixture is thoroughly triturated. After cooling the mixture, the powder is compressed in the form of tablets 0 20 mm and a length of 30 mm

The interaction time of the alloy with water is about 15 s. At the same time, about 3 liters of hydrogen are released per 1 g of alloy.

Example 2. In an arc furnace in an argon medium, 18 g of elemental silicon are fused with 2 g of aluminum. The resulting aluminum silicide is triturated in a cast-iron mortar to a fine powder. 1 g of lithium metal is melted in a porcelain crucible and 20 g of crushed alloy is poured into it with vigorous stirring, then 2 g of sodium metal is added and the whole mixture is thoroughly triturated. After cooling the mixture, the powder is compressed in the form of tablets 0 20 mm and a length of 30 mm

The reaction time of the alloy with water for 10 s with the release of about 1.5 l of hydrogen per 1 g of alloy.

Experiments with this alloy were carried out in an inert atmosphere (argon), since partially formed silanes spontaneously ignite in air.

Example 3. In an arc furnace in an argon medium, 16 g of metallic chromium and 4 g of aluminum are fused. The obtained chromium aluminide is triturated in a cast-iron mortar, then 1 g of lithium metal is melted in a porcelain crucible and 20 g of the alloy is poured into it with vigorous stirring, after which 2 g of sodium metal are added to the crucible and the whole mixture is carefully ground 5. After cooling, the powder is compressed in the form of tablets of 0 to 20 mm and a length of 30 mm.

The alloy interacts with water for about 14 s, releasing about 1 liter of hydrogen per 1 g of alloy.

Example 4. In an arc furnace in an argon medium, 16 g of titanium metal and 4 g of aluminum are fused. The titanium aluminide obtained is triturated in a cast-iron mortar, then 15 g of molten lithium metal is melted in a porcelain crucible and 20 g of alloy are poured into it with vigorous stirring, after which 2 g of sodium metal are added to the crucible and the whole mixture is carefully ground 20. After cooling, the powder is compressed in the form of tablets of 0 to 20 mm and a length of 30 mm.

The resulting alloy is reacted with water for about 4 s with the release of 1.2 g of hydrogen 25 per 1 g of alloy.

Claims (3)

Claim 1. A method of producing hydrogen by reacting water with metal alloys containing aluminum, characterized in that, in order to increase the rate of interaction, alloys containing lithium, sodium or potassium and aluminides of an element standing in a series of voltages to the left of hydrogen are used. 2. The method according to π. 1, characterized in that as an aluminide of an element, a substance is used from the group consisting of elements of Mg, B, Si, Ti, Cr, V, Nb, W, Zr, Hf, Mn, Sb and Fe. 3. The method according to PP. 1 and 2, characterized in that the lithium, sodium or potassium and aluminide of the element are taken in a weight ratio of 1-5: 5-20: 75-94, and the latter contains 10-40% by weight. aluminum.