RU2376522C1 - Hydrogen accumulator - Google Patents

Abstract

FIELD: machine building, distribution of liquids and gases.

SUBSTANCE: invention relates to field of hydrogenous energetics and can be used for storing, transportation and distribution (feeding) of hydrogen in fuel elements and other electric power installations. In hydrogen accumulator, containing hollow microspheres and alloy, forming with hydrogen the metal hydride, inner cavity of microsphere is implemented as free. Metal alloy is applied on external surface of microsphere. Wall of microsphere is implemented as permeable for hydrogen at room temperature.

EFFECT: providing simultaneously of high weight and high volume content of hydrogen, allowing high-speed control properties at filling of accumulator and at its discharge (feeding to consumer), and safety keeping and transportation of hydrogen.

2 dwg, 1 tbl

Description

The invention relates to the field of hydrogen energy and can be used for storage, transportation and distribution (supply) of hydrogen in fuel cells and other power plants.

One of the main problems hindering the development of hydrogen energy is the lack of reliable, safe and energy-intensive devices for storing and transporting hydrogen.

Hydrogen accumulators are known which are made in the form of hollow microspheres, mainly made of glass, into the internal cavity of which hydrogen is pumped under pressure and at an elevated temperature of about 400 ° C, and for subsequent hydrogen extraction, the microspheres are again heated to 400 ° C, and hydrogen from the internal the cavity through the capillaries in the wall enters the space between the microspheres and further to the consumer (See International Application WO 2008/019414, no classification, publ. 02.21.2008).

The disadvantage of this type of battery is the insufficient volumetric content of hydrogen and the complexity of controlling the process of extracting hydrogen from the internal cavity, because it is necessary to heat microspheres to a temperature of 400 ° C to increase the permeability of the wall, the difficulty of regulating heating to obtain a given amount of hydrogen, a long time to create the required hydrogen flow.

Another area in this area is the use of metals that form metal hydrides (metal hydrides) with hydrogen. Metal hydrides are usually placed on substrates, which use various microparticles.

The use of metal hydrides makes it possible to achieve a volumetric hydrogen content of up to 13%, i.e. 13 kg of hydrogen per 100 liters of metal hydride. But the weight content of hydrogen when using metal hydrides is very low, which limits their use as hydrogen accumulators. (See p. USA No. 7279222, B22F 1/00, С01В 3/00, published on October 28, 2004)

The closest in technical essence to the claimed invention is a hydrogen accumulator containing hollow microspheres, the internal cavities of which contain grains of metal hydride, such as palladium. For the introduction of a solution of palladium salt and the penetration of hydrogen into the internal cavity in the wall of the microsphere, pores with a size of 10 to 1000 Angstroms are made, the density of the microsphere is from 1 to 2 kg / cm ³ . Hydrogen is accumulated and stored in a metal hydride (palladium) located in the inner cavity of the microsphere and is extracted from the grains of the metal hydride by heating the microsphere and passing through the pores in the wall. The pores are primarily used for the penetration of a solution of palladium salt into the internal cavity of the microsphere and subsequent deposition of palladium in the form of grains (See International Application WO 2007/050362, published 03.05.2007, MKI C03C 11/00).

The technical task of the proposed invention is the creation of a hydrogen accumulator that provides both high weight and high volumetric hydrogen content, which has high-speed regulatory properties when filling the battery and when it is discharged (supplied to the consumer), ensuring safe storage and transportation of hydrogen, eliminating its ignition and explosion.

The US Department of Energy presents the basic requirements for the parameters of hydrogen storage batteries, the implementation of which provides government support for this area of hydrogen storage and transportation devices. (See Table 1.)

The claimed solution combines the properties of microspheres - a high weight content of hydrogen and the properties of metal hydrides - a high volume content of hydrogen. At the same time, metal hydride performs several functions, namely: it is a barrier to the release of hydrogen from the microsphere, it is a regulator of the supply of hydrogen from the microsphere when the temperature changes. The temperature operating mode of the battery is significantly lower (about 100 ° C) than in known batteries (400 ° C).

The shell (wall) of the microsphere allows it to be filled without heating, but it is also a strong barrier to the perception of the load - the internal pressure of hydrogen, ensuring high battery safety. The internal cavity of the microspheres and the metal hydride simultaneously contain hydrogen.

The invention is illustrated by drawings, where:

figure 1 - schematically shows the proposed battery;

figure 2 - microsphere in the context.

The proposed battery consists of a cylindrical housing 1 with nozzles 2 for charging with hydrogen and nozzles 3 for supply (discharge). The inner space of the housing is filled with microspheres 4. The battery is equipped with a heater 5 for heating the microspheres. Each of the microspheres has an internal cavity 6, which is made free, i.e. does not contain any solid or liquid materials. In the wall (shell) 7 there are capillaries 8, providing the wall with hydrogen permeability at room temperature. A metal (alloy) layer 9 is deposited on the outer surface of the wall, forming a metal hydride with hydrogen, for example nickel lanthanate.

During operation, the battery is charged with hydrogen, which is supplied under pressure through the nozzles 2 into the battery. Hydrogen through the metal hydride layer 9 and capillaries 8 enters the inner cavity 6 of the microspheres, and is also sorbed by the metal hydride layer 9. Thus, in the inner cavity of the microsphere and on its surface in the layer 9 is hydrogen. To produce hydrogen (discharge), the microspheres in the battery are heated to a temperature of 100 ° C, at which hydrogen is released from the metal hydride layer 9. Hydrogen released from the layer 9 is continuously fed with hydrogen from the inner cavity 6 of the microsphere 4 until an equilibrium state is reached at this temperature.

This: eliminates the need for heating the wall of the microsphere to a high temperature of 400 ° C to increase its permeability and obtain the required amount of hydrogen; system performance increases since the mass of microspheres is rather inertial (in the thermal sense) due to the low thermal conductivity of the microspheres at elevated temperatures, i.e. the control action is carried out on the outer layer of the microsphere, where the metal hydride is located, and not on the wall itself, because there is no neobodimosti; hydrogen and at a low temperature (even at room temperature) enters from the internal cavity into the metal hydride layer.

Example

The hydrogen accumulator is filled with microspheres with the following parameters:

the diameter of the microspheres (R ₁ ) - 100 microns;

wall (shell) thickness - 1 micron (R ₂ -R ₁ );

the thickness of the coating layer of the metal hydride is 0.2 microns (R ₃ -R ₂ );

At a hydrogen pressure that fills the microsphere equal to 1000 atm, the hydrogen density inside the microspheres is 50 g / l.

We calculate the weight content of hydrogen in the microsphere, for which we determine the volumes of the microsphere, hydrogen and the shell (wall).

4/3 i (51 ³ -50 ³ ) - 4 / 3π (132651-12500) = 4 / 3π 7651.

The weight of hydrogen is 4 / 3π 125000 × 50 = 4 / 3π 6250000.

shell weight - 4 / 3π 7651 × 2200 = 4 / 3π 16832200.

The ratio of the weight of hydrogen to the weight of the shell = 6250000/16832200 = 0.37 i.e. 37%

For metal hydride, we take a volumetric hydrogen content of 80 g / l, a weight content of 4%, for LaNi, the density is 9.0. We apply a coating thickness of 0.2 microns. The amount of coverage is

4 / 3π (51.2 ³ -51 ³ ) = 4 / 3π (134217.7-132651) = 4 / 3π1566.7.

Coating weight 4 / 3π 1566.7 × 9000 = 4 / 3π 14100300.

Determine the mass (weight) hydrogen content in the microsphere

37 × 132651 + 4 × 1566.7 / 134217.7 = 0.366, i.e. 36.6%.

Determine the volumetric hydrogen content in the microsphere

80 × 1566.7 + 50 × 125000 / 134217.7 = 47.5 g / l.

A comparison of the results with the data in the table shows that in all respects the proposed solution exceeds the requirements of the US Department of Energy for hydrogen batteries.

Table Parameter 2007 year 2010 year 2015 year The weight content of hydrogen, kg / H ₂ / kg 0,045 0.06 0.09 The volumetric content of hydrogen, kg / N ₂ / l 0,036 0,045 0,081 Time to create a complete hydrogen flow at 20 ° С, s four four 0.5 Battery filling time, min 10 3 2.5

Similar calculations were performed for the prototype, i.e. for microspheres with a diameter of 100 microns, with a wall thickness of 10 microns, (density from 1 to 2 g / cm ³ ) grains of tantalum and nickel alloys are located in the inner cavity.

The weight content of hydrogen in such a microsphere is 5%, the volume content of 17%. With the same battery filling time equal to 3 minutes, the time to create a full working stream of hydrogen in the proposed solution was 3 seconds, and in the known 8 seconds.

Thus, on the basis of technical characteristics, the claimed technical solution exceeds the solutions known in the art.

Claims (1)

A hydrogen accumulator containing hollow microspheres and an alloy forming a metal hydride with hydrogen, characterized in that the inner cavity of the microsphere is made free, a metal alloy is deposited on the outer surface of the microsphere, and the wall of the microsphere is permeable to hydrogen at room temperature.

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