TW201925081A - Method and container tank of mobile-producing hydrogen by added water - Google Patents

Abstract

A method and container tank of mobile-producing hydrogen by added water. The method introducing placing an aluminum powder and a solid sodium aluminate powder in a container jar; a certain amount of water into the container jar at room temperature; producing a hydrogen gas and an aluminum hydroxide; and outputting the hydrogen until the Aluminum powder completely converted to the aluminum so far.

Description

Mobile water adding method for generating hydrogen and container tank

The present invention relates to a process for producing hydrogen gas and a container can, and more particularly to a method and container for low-cost mobile water addition to produce hydrogen.

Water is the most abundant element in nature. It is stable and safe in nature. The hydrogen atoms in its composition can form hydrogen as a clean energy source for human use. For decades, the industry has struggled to find an economically safe and effective way to make cheap and easy-to-use hydrogen as an energy source.

At present, a fixed large-scale hydrogen storage system is suitable for the end of a pipeline of a hydrogen production plant for storing a large amount of hydrogen, usually using a high-pressure gas cylinder to store 1.5 wt% of hydrogen at 150 atmospheres; and a low-temperature liquid freezing method at a temperature It can store 13.0wt% hydrogen by weight below 252.8 degrees Celsius or 20.4K, but this cryogenic storage system does not contain equipment such as compressors and cooling systems; small or mobile hydrogen storage methods, including low pressure A hydrogen absorbing alloy having a storable pressure of less than 10 atm and a hydrogen weight of 1.045 wt%; a carbon nanotube adsorbing hydrogen at a pressure of 54 atm, minus 160 degrees Celsius or 113 K, and a hydrogen weight percentage of 7.22 wt%. In addition, the formation of hydrogen by the Chemical Hydride Hydrolysis Reaction can also greatly reduce the volume and/or weight of hydrogen storage.

Metal hydroxides such as sodium borohydride (NaBH4) have proven to be safe and capable of achieving a weight percent hydrogen capacity of 21.3 wt%. The hydrolysis reaction of a chemical hydride such as sodium borohydride can significantly accelerate the reaction by adding an acid (Acid) or some catalytic metal salt. However, the use of sodium borohydride and its corresponding chemical hydrides in the production of hydrogen has its own major drawbacks: (1) it is very unstable and sensitive to moisture in the air; with current fossil fuels Compared to the price of the material, it is very expensive.

On the other hand, different active metals, such as lithium, sodium, magnesium, aluminum and the like, can react with aqueous solutions to produce hydrogen, of which aluminum, magnesium and their alloys have been considered to be the most suitable materials for the development of future hydrogen production processes. One gram of aluminum and magnesium reacted with the aqueous solution to produce hydrogen (100%) having values of 1.245 liters (L) and 0.95 liters (L), respectively. The corresponding chemical hydrides of aluminum and magnesium, such as aluminum hydride (AlH ₃ ) and magnesium hydride (MgH ₂ ), produce 2.24 liters (L) and 1.88 liters (L) per gram, respectively.

Aluminum can be stored and transported in a safer and cheaper way than hydrogen. Aluminum, which is stable under normal conditions, is comparable to magnesium, but is 10-20 times lower than metal hydrides such as sodium borohydride. In addition, aluminum can be recycled from waste, such as aluminum cans, and reused as a source of hydrogen and electricity.

The reaction of aluminum with aqueous sodium hydroxide is as follows: 2Al+6H ₂ O+2NaOH→2NaAl(OH) ₄ +3H ₂ (1)

NaAl(OH) ₄ →NaOH+Al(OH) ₃ (2)

2Al+6H ₂ O→2Al(OH) ₃ (3)

Initially, the hydrogen production reaction formula (1) consumes sodium hydroxide, but when the aluminate concentration in the aqueous solution exceeds the saturation limit, the aluminate undergoes decomposition reactions (4) and (5), which produce crystals of aluminum hydroxide. The precipitate was regenerated with sodium hydroxide.

NaAl(OH) ₄ →Na ⁺ +Al(OH) ₄ ^- (4)

Na ⁺ +Al(OH) ₄ ^- →NaOH+Al(OH) ₃ (5)

In aluminum/air battery applications, the electrochemical reaction also includes the reaction formula (2), and finally the hydrogen production reaction of aluminum in an aqueous sodium hydroxide solution can be described by the reaction formula (3).

US Patent No. 6,638,493 demonstrates that the entire aluminum does not consume sodium hydroxide during the aqueous sodium hydroxide solution and is capable of regenerating hydroxyl ions from the aluminum to produce hydrogen. The main reason for producing hydrogen by corrosion reaction is aluminum watch The surface is easily passivated, but passivation optimizes several parameters such as temperature, sodium hydroxide concentration, aluminum material form, and promoter composition minimization.

Since the aluminum corrosion is an exothermic reaction, the hydrogen generation system by the corrosion reaction with aluminum does not need to be externally heated. In addition, the chemical corrosion reaction can be achieved under mild temperature and pressure conditions to provide a stable and compact source of high purity hydrogen. As a result, the price of hydrogen produced by the corrosion reaction is cheaper than that of the chemical hydride. Assuming a 100% hydrogen generation efficiency is achieved, a weight percent hydrogen of 11.2 wt.% can be achieved, which is greater than the US Department of Energy's 2020 research target of 4.5 wt.% hydrogen weight percent. If necessary, 11.2wt.% To 21.3wt% of aluminum and sodium borohydride (NaBH ₄₎ and then hydrogenated to further improve the composition in the form of hydrogen storage capacity. Table 1 shows the weight and volume percentage of hydrogen production by hydrolysis of aluminum.

Although it is feasible to produce high-purity hydrogen by reacting aluminum powder with aqueous sodium hydroxide solution, there is still sodium hydroxide as a corrosive strong alkali aqueous solution, chemical hydrogen. The high cost of the compound is easy to absorb moisture in the air...etc.

There are two related experimental references for aluminum-water reactions, including cylindrical aluminum blocks, uncompacted aluminum powders, and aluminum samples of various densities in reaction with different concentrations of aluminum hydroxide-water at near room temperature. Hydrogen, formation of sodium aluminate, precipitation of aluminum hydroxide, and regeneration of sodium hydroxide are produced under the conditions. A high-purity hydrogen generating apparatus of the formula (1) to (5) for promoting aluminum-water reaction using aluminum and a high-concentration aqueous sodium hydroxide solution is disclosed in U.S. Patent Nos. 6,638,493 and 6,800,258. The preservation of externally added aluminum powder is also a problem due to the safety concerns of using a high concentration aqueous sodium hydroxide solution which causes safety concerns and an increase in the weight of the system.

On the other hand, in order to improve the reaction rate, the addition of aluminum oxide (Oxide Promoters) and aluminum nanopowder powder and aqueous solution at pH4-pH9 and temperature of 10 to 90 °C is indeed feasible, but there is still a percentage of reaction still below 10%, nano Aluminum powder costs are high and storage is not easy. Water-soluble inorganic salts, such as sodium chloride (NaCl) and potassium chloride (KCl), can cause local pitting and rupture of the aluminum oxide layer on the aluminum particles to promote the hydrogen reaction of the aluminum-water solution to improve the reaction rate. However, since the inorganic salt powder and the aluminum powder are subjected to nano-ball milling in a 1:1 weight ratio, problems such as high cost of ball-milling aluminum salt compounding and difficulty in storage remain. Low-melting-point aluminum alloys, such as aluminum-gallium alloys, aluminum-doped aqueous solutions of nano-doped metal oxides and inorganic salts have problems such as high cost and improved storage of nano-mixtures.

In order to solve the above technical problem, the present invention discloses a mobile method for producing hydrogen by adding water, comprising: placing an aluminum powder and a solid sodium aluminate powder in a container tank; and introducing a certain amount in a room temperature environment. Water enters the vessel; produces hydrogen and aluminum hydroxide, and outputs the hydrogen until the aluminum powder is completely converted to the aluminum hydroxide until.

The invention also discloses a mobile tank for adding hydrogen to produce hydrogen, comprising: placing an aluminum powder and a solid sodium aluminate powder in the container; and introducing a certain amount of water into the container under a room temperature environment; a tank; producing hydrogen gas and aluminum hydroxide, and outputting the hydrogen gas until the aluminum powder is completely converted into the aluminum hydroxide.

The present invention is carried out in a reaction at room temperature, except that only water is added, the process of producing hydrogen does not require the addition of any energy source and the main reactant by-product is non-toxic aluminum hydroxide.

1‧‧‧ Container cans

2‧‧‧Water injector inlet

3‧‧‧Rubber

4‧‧‧ Hydrogen outlet

5‧‧‧Quick joint

6‧‧‧ Hydrogen

7‧‧‧ water

8-1‧‧‧Sodium aluminate powder

8-2‧‧‧Aluminum powder

22‧‧‧Syringe

200‧‧‧A mobile tank for generating hydrogen gas by moving water according to an embodiment of the present invention

Figure 1. Experimental setup of prior art hydrogen generation.

2 is a view showing a container for moving hydrogen to generate hydrogen gas according to an embodiment of the present invention.

Figure 3 is an experimental diagram of the maximum hydrogen production rate of an embodiment of the present invention.

Figure 4 is an experimental view showing the percentage of hydrogen generation in an embodiment of the present invention.

A detailed description of the embodiments of the present invention will be given below. While the invention will be described in conjunction with the embodiments, it is understood that the invention is not limited to the embodiments. Rather, the invention is to cover various modifications, equivalents, and equivalents of the invention as defined by the scope of the appended claims. It is understood that the illustrations are not drawn to scale, and only a

2 shows a container can 200 for generating hydrogen by mobile watering in accordance with an embodiment of the present invention. The container tank 200 for moving water to generate hydrogen gas includes a container tank 1 and a rubber 3, and the rubber 3 is used to seal the opening portion of the container tank 1. hydrogen Solid sodium aluminate powder 8-1 and aluminum powder 8-2 were placed in the production tank 1. In one embodiment, the solid sodium aluminate powder 8-1 is intimately mixed with the aluminum powder 8-2.

The rubber 3 includes a water injector inlet 2 and a hydrogen outlet 4. The water injector inlet 2 can provide a canister 200 that delivers a quantity of water 7 via a syringe 22 to the outside of a canister 200 that produces hydrogen from mobile water.

When a certain amount of water is injected into the container tank 200 for generating hydrogen by moving water, the aluminum-water reaction begins with the mass diffusion of the surface aluminum oxide layer to become a control step for generating hydrogen by decomposing water, and then the surface of the aluminum powder is oxidized. Aluminum produces hydrogen through the following corrosion mechanisms: Al ₂ O ₃ +3H ₂ O→Al ₂ O ₃ ‧3H ₂ O (6)

2NaAlO _2(aq) →2Na+ +2AlO ₂ ^- (8)

2Al(OH) ₄ ^- →2Al(OH) ₃ +2OH ^- (9)

Al+3H ₂ O+OH-→Al(OH) ₄ - +3/2H ₂ (10)

Al(OH) ₄ ^- →OH ^- +Al(OH) ₃ (11)

The reaction of aluminum powder and water produces hydrogen. The maximum hydrogen production rate occurs at the beginning of the reaction. Since the surface of the aluminum is fresh and alumina-free, it is directly hydrolyzed with water to form aluminum oxide and hydrogen gas. As the alumina coating increases the resistance of the water molecules to diffuse through the surface, the absence of a corrosion promoter will gradually reduce the rate at which hydrogen is produced until it stops.

In one embodiment, the hydrogen outlet 4 further includes a hydrogen quick coupler 5 for convenient connection to a fuel cell generator (not shown), each kilogram of aluminum being convertible to about 0.112 kilograms of hydrogen.

Figure 3 shows the aluminum-water reaction experiment at different concentrations of sodium aluminate. The initial surface of aluminum is fresh and alumina-free, so the reaction rate of hydrogen generation is determined by the specific surface area of aluminum powder. The sodium aluminate powder dissolves into hydroxide ions (OH ^- ) when it encounters water, and the aluminum oxide (Al ₂ O ₃ ) contacts the water to form a hydration reaction formula (6), and the hydration reaction forms aluminum trihydrate on the surface of the aluminum powder. Stone (Al ₂ O ₃ ‧3H ₂ O), at which time the hydroxide ion in the aqueous solution is combined with the gibbsite (Al ₂ O ₃ ‧3H ₂ O) on the surface of the aluminum powder to form aluminum hydroxide ions (Al(OH) ₄ ^- ) Reaction formula (7).

Sodium aluminate (NaAlO ₂ ) dissolved in water in aqueous solution to form aluminate ion (AlO ₂ ^- ) and sodium ion (Na ⁺ ) reaction formula (8), aluminate ion (AlO ₂ ^- ) as nucleated seed, when dissolved The aluminum hydroxide ion (Al(OH) ₄ ^- ) in the water exceeds the saturation concentration, so the oxide layer (Al ₂ O ₃ ) originally covering the surface of the aluminum is precipitated by the nucleation seed in the water (Al(OH) ₃ ) Reaction formula (9) with regenerated hydroxide ion (OH ^- ).

During a period of induction, partial dissolution transformation occurs corrosion, and the reaction of alumina (Al ₂ O ₃ ) and water (3H ₂ O) is carried out to precipitate aluminum hydroxide (2Al(OH) ₃ ) by nucleating seeds in aqueous solution. The reaction formula (6) to the reaction formula (9), at this time, the aluminum powder re-exposed the fresh aluminum surface layer. Fresh aluminum (Al), hydroxide ion (OH ^- ) reacts with water (3H ₂ O) to produce hydrogen (6) and reaction formula (11). The reaction continues to produce hydrogen (3/2H ₂ ) and aluminum hydroxide (Al(OH) ₃ ) precipitation and regeneration of hydroxide ions (OH ^- ), wherein aluminum hydroxide (Al(OH) 3) itself is harmless Product.

Under the action of a sodium aluminate (NaAlO ₂ ) corrosion promoter, as long as the concentration of sodium aluminate (NaAlO ₂ ) per liter of water is greater than 0.7 moles, sufficient hydroxide ion (OH ^- ) concentration can be provided. The hydrated oxidation (Al ₂ O ₃ ‧3H ₂ O) on the surface of the aluminum powder is corroded, and the aluminum hydroxide ion (Al(OH) ₄ ^- ) in the aqueous solution is precipitated by supersaturation, and the aluminate ion (AlO ₂ -) is formed. The seeds of the core are precipitated to form aluminum hydroxide (Al(OH) ₃ ) (not shown).

Under the conditions of Fig. 3, the hydrolysis reaction of aluminum powder can be stably and continuously maximized under the condition of 60 minutes, that is, the percentage of hydrogen gas generated at 100%, as shown in Fig. 4. If the reaction time is 60 minutes, the experiment of Figure 4 shows a supersaturation concentration of 0.7 moles. The experimental reagents of Fig. 3 and Fig. 4 are vacuum packed as they are, and the deionized water prepared by the laboratory is used as the water for injection, and the aluminum-water reaction is carried out. The water and samples tested were freshly prepared before application.

In summary, the present invention provides a mobile method for producing hydrogen by adding water, comprising: placing an aluminum powder and a solid sodium aluminate powder in a container; and introducing a certain amount of water into the container under a room temperature environment; A hydrogen gas and aluminum hydroxide are produced, and the hydrogen gas is output until the aluminum powder is completely converted into the aluminum hydroxide. In one embodiment, the quantitative water of the present invention is contacted with the surface of the aluminum powder to generate the hydrogen gas bubbles and the surface of the aluminum powder is oxidized, and the solid sodium aluminate powder is dissolved into the amount of water to form a liquid sodium aluminate and a hydroxide ion; wherein the concentration of the hydroxide ion is sufficient to cause a corrosion reaction on the surface oxide layer of the aluminum powder, and supersaturation to form aluminum hydroxide.

The present invention resides in that the reaction is carried out in a room temperature environment. Except for the addition of water, the process of producing hydrogen does not need to add any energy including electric energy, heat source, light energy and the like. In addition to the addition of water, the main reactant by-product is non-toxic aluminum hydroxide.

The above detailed description and the accompanying drawings are only typical embodiments of the invention. In addition, other processes and steps may be combined with the processes and steps discussed herein, that is, there may be multiple processes and steps before, during, and/or after the steps shown and described herein. Importantly, embodiments of the present invention can be implemented in conjunction with other processes and steps without significant impact. In general, the various embodiments of the present invention may replace portions of the conventional process without significantly affecting its peripheral processes and steps. Therefore, the embodiments disclosed herein are intended to be illustrative and not restrictive, and the scope of the invention is defined by the appended claims

Claims (10)

A method for generating hydrogen by mobile water, comprising: placing an aluminum powder and a solid sodium aluminate powder in a container; and introducing a certain amount of water into the container at room temperature; generating a hydrogen gas and One aluminum hydroxide, and the hydrogen gas is output until the aluminum powder is completely converted into the aluminum hydroxide. The method of claim 1, wherein the quantitative amount of water contacts the surface of the aluminum powder to generate the hydrogen and the surface of the aluminum powder is oxidized, and the solid sodium aluminate powder is dissolved into the amount of water to form a liquid aluminum. Sodium and monohydric hydroxide ions; wherein the concentration of the hydroxide ions is sufficient to cause a corrosion reaction on the surface oxide layer of the aluminum powder, and supersaturation to form aluminum hydroxide. The method of claim 1, wherein the hydration reaction of the aluminum oxide on the surface of the aluminum powder forms a gibbsite. The method of claim 1, wherein the liquid sodium aluminate concentration is greater than 0.7 moles. The method of claim 1, wherein the hydrogen has a weight percent capacity of 11.2 wt.%. A mobile tank for adding hydrogen to generate hydrogen, comprising: placing an aluminum powder and a solid sodium aluminate powder in the container; and introducing a certain amount of water into the container at room temperature; generating a hydrogen gas With aluminum hydroxide, and outputting the hydrogen until the aluminum powder is completely converted to the aluminum hydroxide. The container according to claim 6, wherein the quantitative water contacts the surface of the aluminum powder to generate the hydrogen and the surface of the aluminum powder is oxidized, and the solid sodium aluminate powder is dissolved into the liquid to form a liquid. Sodium aluminate and a hydroxide ion; wherein the concentration of the hydroxide ion is sufficient to cause oxygen on the surface of the aluminum powder The layer undergoes a corrosion reaction and supersaturate to form aluminum hydroxide. The container according to claim 6, wherein the hydration reaction of the surface of the aluminum powder forms a gibbsite. The container according to claim 6, wherein the liquid sodium aluminate concentration is greater than 0.7 mol. The container can of claim 6, wherein the hydrogen has a weight percent capacity of 11.2 wt.%.