KR20070009981A - Fuel blends for hydrogen generators - Google Patents

Abstract

The present invention relates to improved aqueous fuels for hydrogen generators and a method for using them in the production of hydrogen. The present invention also relates to a system of using the subject aqueous fuels to generate hydrogen gas for use in a fuel cell or other device. The subject fuels contain a mixture of boron hydrides, at least one of which is a metal salt, including metal borohydrides, higher boranes and metal higher boron hydrides. The subject aqueous fuels contain a mixture of boron hydrides having a positive ionic charge (+IC) to boron ratio of between 0.2 and 0.4 or between 0.6 and 0.99. Preferred fuels contain a mixture of boron hydrides having an (+IC) to boron ratio between 0.2 and 0.3 or between 0.7 and 0.8. Mixtures containing a metal borohydride also contain a metal hydroxide to stability it against premature hydrolysis in the aqueous fuel media. ® KIPO & WIPO 2007

Description

FUEL BLENDS FOR HYDROGEN GENERATORS

The present invention relates to a mixture of borohydride salts for hydrogen evolution.

For about 50 years it has been known that various boron hydrides (herein referred to as "borohydrides"), in particular their metal salts, are useful for hydrogen evolution. In addition, "Sodium borohydride: Its Hydrolysis and Its Use as a Reducing Agent in the Generation of Hydrogen", J. Am. Chem. Soc. , Vol 75, pp 215-219,1953, and in "Hvdrogen Generation by Hydrolysis or Alcoholysis of a Polvhvdropolvnorate-Group VIII Metal Mixture" USP No. As reported by G. W. Parshallin at 3,166, 514, hydrogen is generally known to occur through hydrolysis catalyzed by acids or metals. This early work was improved by the development of systems that regulate hydrogen evolution as needed. US Pat. No. 6,534,033 discloses contacting aqueous solution of borohydride by injecting a solution through a chamber containing a metal catalyst and controlling the generation of hydrogen by converting the borohydride into hydrogen gas and borate in close quantitative yield according to equation (1). Is described.

(1)

(One)

There are factors involved in selecting specific borohydride salts for use in the process illustrated in Equation 1. The most important of these is the solubility in water. In general, borohydride has a solubility of about 7% to about 35% by weight in water at 25 ℃. Lithium borohydride has 7% solubility, potassium borohydride is about 19% and sodium borohydride is about 35% dissolved. For this reason, sodium borohydride, like several others, especially including stability and convenience, is selected as the salt of the water soluble fuel for the hydrogen generator. Sodium borohydride having a high gravimetric hydrogen storage density of about 7.4 wt.% In saturated solution at ambient temperature is also preferred for use in the present invention.

As noted above, in the concentrate of sodium borohydride, sufficient water is initially required to complete the hydrolysis of sodium borohydride, as well as to maintain the borate product in solution. However, as hydrolysis proceeds and water is consumed as in Equation 1, the borate product can be maintained in solution and the amount of water present is reduced. If the amount of water in the system is reduced to the point where the borate precipitates in solution among all plumbings connecting the catalyst-filled reactor or storage tank to the reactor, the hydrogen generator is gradually incremented to the point of shutdown, decomposition and washing. Can be blocked.

Because of the possibility of borate products precipitate out of solution, the concentration of sodium borohydride in water-soluble fuels for hydrogen evolution is limited to about 15% to 20% by weight despite the relatively high solubility. The solution produced about 4.25 Wt. -%. This is recognized as a practical limit for hydrogen evolution (see for example Von Dohren, "Raney Catalyst for Generating Hydrogen by Decomposition of Boranes", USP 3,615, 215). This limit reduces the corresponding hydrogen storage and will not be considered optimal in environments with volumes above liquid level. Typically, in this situation, hydrogen enriched fuels are preferred, in particular to maximize the amount of hydrogen stored per unit volume of fuel. Such fuels are provided by the present invention.

Summary of the Invention

According to the present invention, a cation selected from the group consisting of alkali metal cations, alkaline earth metal cations, aluminum cations and ammonium cations such that the mixture has a pre-calculated molar ratio of solvated cation charge (+ IC) to boron atoms A mixture of boron hydrides comprising at least one borohydride salt formed, which provides a fuel mixture for hydrogen generation that maximizes the solubility of the borate salt. The fuel mixture mitigates the early condensation of the borate product in the hydrogen generating mechanism while promoting high gravity hydrogen storage where the fuel can be used for hydrogen evolution. Fuel mixtures comprising sodium borohydride in the range of 30 to 38% by weight, and thus corresponding to solutions having a gravity hydrogen storage density in the range of 6.4 to 8% by weight, do not have the disadvantages of known fuels and are effective in producing hydrogen to produce hydrogen. Can be decomposed. Also provided are improved methods and systems for generating hydrogen using the fuel mixtures described herein.

Detailed description of the invention

The present invention relates to a water-soluble fuel for hydrogen generation containing a mixture of certain boron hydrides. The mixture of boron hydrides herein is directed to borane comprising a polyhedral borane and an anion of polyhedral borane or borohydride. More specifically, the present invention relates to a water soluble fuel containing a mixture of boron hydrides having a calculated molar ratio of solvated cation charge (+ IC) to boron atoms. This ratio maximizes the solubility of the borate product of the hydrolysis reaction that generates hydrogen, not the components of the fuel. By maximizing solubility herein, the optimum solubility of the borate product in relation to the concentration of borohydride in the fuel is obtained, thereby allowing water in hydrolysis of the boron hydrides, for example, as shown in borohydride of equation (1). Minimize the deposition of borate products during hydrogen evolution as a result of consuming

The ratio of the cationic charge ( ⁺ IC) to boron is determined according to the following manner by the present invention using alkali metal salts as in the examples. Alkali metal borate salts are commonly described in the format jM ₂ O.k B ₂ 0 ₃ .XH ₂ 0, of which M is selected from lithium, sodium and potassium. For example, mineral borax may be described as a j = 1, k = 2 and X = 10, and thus _{Na 2 O · 2B 2 0 3} · 1OH 2 0 or _{Na 2 B 4 0 7 · 10H} 2 0. One of ordinary skill in the art recognizes that almost all ratios of j to k form solid crystal borate salts, but the solubility of the crystals in water will vary. The two temperature dependent solubility maximums are cases where the ratio of j to k is in the range of 0.2 to 0.4 and is also in the range of 0.6 to 0.99.

The solubility of borate salts by the ratio values of j to k described above has been known for many years. See, eg, Nies and Holbert, Journal of Chemical and Engineering Data, Vol. 12, No. 3, pp 303-313,1967, Adams, " Boron , Metallo - Boron Compounds and Boranes "John Wiley & Sons, page 81,1964, and Garret," Borates, Handbook of Deposits, Processing, Properties and Use ", Academic Press, 1998, page 454. Salts of the Formulas Above (Dual , M is potassium or lithium) is similar to the solubility maximum (Adams ibid, pp 81 and 83, Reburn and Gale, Journal of Physical Chemistry, Vol. 59, No. 19,1955). As such, these values have been used in known literature for many years, but so far the values found in fuel mixtures for hydrogen generators are unknown.

According to the invention, the fuel mixture for the hydrogen generator has a molar ratio value of the cationic charge ( ⁺ IC) to boron atoms in the range of 0.2 to 0.4, preferably 0.2 to 0.3, or 0.6 to 0.99, preferably 0.7 to 0.8. A mixture of boron hydrides. The fuel mixture according to the present invention combines at least one other borohydride with a cation (M) selected from alkali metals such as sodium, lithium, potassium, alkaline earth metals, aluminum or ammonium so as to achieve the desired ratio. Borohydride salts. Suitable boron hydride salts include borohydride salt (MBH ₄ ), triborohydride salt (MB ₃ H ₈ ), decahydrodecaborate salt (M ₂ B ₁₀ H ₁₀ ), tridecahydrodecaborate salt (MB ₁₀ H ₁₃ ), dodecahydrododecaborate salt (M ₂ B ₁₂ H ₁₂ ), octadecahydroicosaborate salt (M ₂ B ₂₀ H ₈ ) and decabolane (14) (B ₁₀ H ₁₄ ) [above, M is selected from the group consisting of alkali metals, alkaline earth metals and aluminum]. There is, but is not limited to, a related neutral borate compound compatible with borohydride salts.

It is within the scope of the present invention to use mixtures of higher boron hydrides so that the desired molar ratio of cationic charge ( ⁺ IC) to boron atoms can be obtained. Although the mixture may contain the above-mentioned borate salts, it is also necessary to include at least one borohydride salt in order to obtain the desired ( ⁺ ICs) ratio for boron. Mixtures of cationic boron hydrides according to the present invention include metal borohydrides, preferably sodium borohydride, and decaborane (14); Metal triborohydride and metal dodecahydrododecarborate; Metal borohydride and metal triborohydride; And metal borohydride and metal dodecahydrododecaborate are preferred, but are not limited thereto. It is not critical that the ⁺ IC / B ratio of the mixture of boron hydrides in the fuel of the present invention be in the range of 0.2 to 0.4 or 0.6 to 0.99, but this range is advantageous. The selection of the boron hydride component and thus the ⁺ IC / B ratio takes into account the chemical reactivity and the effect on the individual health of the individual boron hydride compounds, as well as economic considerations such as relative availability and cost for the individual boron hydride compounds. Can be determined. Whether a particular mixture is within one or the other can be determined by other factors such as the relative solubility of various boron hydrides, the operating temperature range of the desired mixture, and the like, which is considered within the field of view of one of ordinary skill in the art.

The cationic component of the above higher borohydride may be an alkaline earth metal cation or an aluminum cation in addition to the alkali metal cation as described in connection with the borohydrides. The cation is preferably selected from the group consisting of sodium, lithium, potassium, beryllium, magnesium, calcium or aluminum. The fuel mixture of the present invention contains at least one borohydride salt and its cationic component need not be identical. As mentioned above, the cationic component for the metal borohydride of the fuel mixture of the present invention is preferably sodium. One of ordinary skill in the art recognizes that borohydride salts are present in a water soluble fuel mixture for gas generators and will readily hydrolyze unless they are stable to hydrolysis by the presence of strong bases. Suitable bases for this purpose include the respective metal hydroxides given above, which are strong bases such as, for example, sodium hydroxide when the component is sodium borohydride. Among the preferred fuel mixture containing a borohydride salt by the present invention, the cationic component of the stabilizer when calculating the molar ratio of cationic charge ⁽⁺ IC) to boron as described later it is to be counted in the equation. Likewise, in order to prepare a stable aqueous solution of decaborane 14, an alkali stabilizer must be present and the metal cation component of the stabilizer contributes to the cationic charge ( ⁺ IC) for the fuel mixture. Many boron-rich hydrides (such as M ₂ B ₁₂ H ₁₂ , M ₂ B ₁₀ H ₁₀ and M ₂ B ₂₀ H ₁₈ ) are stable in neutral aqueous solutions.

According to the present invention, the calculation of the molar ratio of cationic charge ⁽⁺ IC) to boron was developed according to the following manner. As shown, a water soluble fuel solution containing 35% by weight sodium borohydride, such as by adding cationic boron hydride containing 3% by weight sodium hydroxide for stability, was used as follows using 100 grams of the fuel solution. The measured j to k ratio is 1.08. In the examples, all boron is derived from sodium borohydride, so the number of moles of boron is calculated directly at the borohydride concentration in the fuel solution as shown below.

Using the same calculation, sodium borohydride provides 0.925 moles of Na when sodium and boron are present in a molar ratio of 1: 1 of them. However, there is additional sodium ( ⁺ IC) provided by the sodium hydroxide stabilizer, which can be determined in a similar manner to determining the boron concentration as shown below.

If the number of moles of sodium equivalent to the cationic charge ( ⁺ IC) is known, the ratio can be calculated by dividing the total number of moles of sodium by the total number of moles of boron as described below.

Thus, a solution containing 35% by weight sodium borohydride and 3% by weight sodium hydroxide has a ( ⁺ IC) ratio to boron of 1.08, which is outside the maximum solubility range ratio as described above. This reacts so that the borate product remains in solution and does not precipitate to cause the apparatus to solidify, effectively limiting the use of the concentrated fuel solution in the gas generator without introducing additional water.

Since higher boron hydride is abundant in boron with respect to the metal components of the fuel mixture, the presence of higher boron hydride in the fuel solution as described above controls the ratio of j to k below the preferred ratio of the present invention. Since the solubility of the borate produced from the fuel is significantly higher than that of conventional water soluble sodium borohydride solutions, more borohydride, and more hydrogen, is added to the fuel solution to reduce the risk of coagulation of the borate product. Included. Another advantage of the fuel mixture of the present invention is that when it contains a metal borohydride such as sodium borohydride, many of the boron-rich higher boron hydrides are stable in aqueous solution and do not require the addition of basic stabilizers. Another advantage of the mixed fuel solution of the present invention is that some higher boron hydrides are hydrolyzed in aqueous solution to produce some acidic products that partially neutralize all metal hydroxides present in turn, and contain only metal borohydride and metal hydroxides. Fuel is used to produce a release that is less fragile than the resulting metal metaborate / metal hydroxide mixture.

 Another advantage of the novel water soluble fuel mixtures of the present invention is that even if some coagulation occurs upon cooling in the hydrolysis reactor, the product readily dissolves in water. In contrast, when the fuel contains only metal borohydride and hydroxides such as, for example, sodium borohydride and hydroxides, the resulting borate mixture may slowly dissolve and produce crusts that are difficult to remove in the catalyst chamber. The borate mixtures produced using the fuel mixtures of the present invention can be easily removed by simple means in a full chamber and associated apparatus including water, thus increasing catalyst life and reducing the normal downtime of the hydrogen generation system. Can be. The ease of cleaning as well as the increase in the interval between subsequent operation of the hydrogen generation system and the required cleaning is a distinct economic advantage of the fuel mixture of the present invention.

The description of the difference in solubility of the product resulting from the fuel mixture of the present invention compared to fuel mixtures containing only metal borohydrides such as sodium borohydride is typically the minus temperature of solvation bound to borate. Sodium metaborate, for example, substantially cools the solvent when added to a solution, thus slowing the dissolution reaction. In contrast, sodium borate salts in which the molar ratio of cationic charge ( ⁺ IC) to boron in the maximum solubility range according to the invention is the positive temperature of the solvation, thus actually promoting the dissolution reaction and producing hydrogen (O'Brien et al, "Amorphous Sodium Borate Composition" USP No. 2,998, 310).

As used herein, the term "water soluble fuel" includes a slurry in which some of the components are dissolved and some of the components are solid, and / or an aqueous liquid in which all components are dissolved. In addition, hydroalcoholic mixtures have the advantage of producing the water-soluble fuel of the present invention in terms of lowering the freezing point of the fuel and thus extending the operating temperature range. In general, higher boron hydrides are soluble and stable in hydroalcohol solutions, especially when stabilizers are present to raise the pH. Alcohols used to prepare hydroalcohol solutions include lower alkanols, in particular methanol and ethanol. In this specification, a water soluble fuel prepared to form a slurry for the economics of operation and storage is intended to be combined with a sufficient amount of water when used to form a solution of the component confirming the maximum solubility ratio mentioned herein. Include.

According to the present invention, an improved system for generating hydrogen and a method for generating hydrogen are provided. The method comprises contacting an improved water soluble fuel mixture of the present invention of boron hydride with a cationic charge ( ⁺ IC) relative to the number of moles of boron in contact with a catalyst that promotes hydrolysis of boron hydride to produce hydrogen. The system provided by the present invention includes a means for contacting a water soluble fuel mixture of boron hydride with a catalyst. The means includes means for physically separating the fuel and the catalyst when hydrogen gas is not needed. If hydrogen is needed, an aqueous fuel solution is brought in contact with the catalyst and hydrogen is produced so that the hydrolysis reaction can occur. Separation of the catalyst can be accomplished by using any mechanical, chemical, electrical and / or magnetic method which is readily recognized by one skilled in the art. In one embodiment, a separate chamber was used to separate the aqueous fuel solution and the catalyst. The water soluble fuel can be stored in the fuel reservoir, pumped into the chamber in which the catalyst is stored in contact with the catalyst, and generate hydrogen through the hydrolysis reaction shown in equation (1) for the metal borohydride. In another embodiment, the catalyst can be introduced into a tank containing the hydride solution of the present invention and removed.

In another embodiment, the hydrolysis catalyst is an acid, and both the fuel and the catalyst are pumped into the reaction chamber in a liquid state to generate hydrogen. In this embodiment, the fuel solution and catalyst solution must be stored in separate vessels and pumped separately into the reactor to start and maintain the hydrolysis reaction. Acid catalysts are preferably strong inorganic acids, in particular hydrochloric acid, sulfuric acid and phosphoric acid.

The improved fuel solution of the present invention can be pumped into the system batchwise or continuously. The catalyst chamber may also include at least one conduit through which a fuel solution can flow directly into and out of the chamber at different stages of the catalytic reaction. The conduit can also function as an output channel for preventing hydrogen gas generated by the hydrolysis reaction.

It is important that an insoluble metal or metal that is bound to, entrapped, and / or coated on a substrate may not require a separate chamber when used as a catalyst during the reaction shown in equation (1). Suitable substrates for metal catalysts include plastics, polymers, textiles, metals, metal oxides, ceramics or carbonaceous materials. In a preferred embodiment, the system of the present invention comprises a metal mesh and fibers, as described in US Pat. No. 6,534,033, incorporated herein by reference, and physically within and / or on a porous substrate or a non-breathable substrate. Or containment systems for capturing the catalyst by chemical means. In all of the above embodiments, the hydrogen generation system may include only one chamber, and separation of the catalyst from the water-soluble fuel is achieved by removing the insoluble catalyst or the supported catalyst from the solution, thereby And the contact between boron and hydride. In conclusion, if a hydrogen product is desired, the catalyst can be simply reintroduced into the water soluble fuel to promote reaction (1) as described above.

Since the improved water soluble fuel of the present invention is stable in the absence of a catalyst, the generation of hydrogen according to reaction (1) can be almost controlled by controlling the contact of boron hydride with the catalyst. Depending on the operating mechanism and arrangement of the hydrogen generation system, it may be adjusted by adjusting the flow of water soluble fuel to the catalyst or recovering the catalyst from the fuel solution. In systems using supported catalysts or deposited catalysts, the hydrogen product can be controlled by separating or contacting the coupling catalyst from the boron hydride fuel solution. For example, the catalytic metal may be attached by a piston or the like and pumped in and out of the fuel solution as needed for hydrogen. Alternatively, the supported catalyst can be stored in a separate chamber and the pumping of the fuel solution into the chamber is controlled by a valve and appropriate control means. In the case of homogeneous catalysts such as acid solutions, the control of hydrogen evolution can be achieved by controlling the flow of the boron hydride fuel solution or catalyst solution or both. The mixing chamber is preferably mixed or pumped with the two solutions into the chamber so that the hydrolysis reaction can occur.

In another embodiment, acid salts of polyhedron boron hydrides such as hydronium salts (double cations are H +) and ammonium salts (double cations are NH ₄ +) can be used in combination with a hydrogen generating promoter and fuel component. . Suitable promoter components include H ₂ B ₁₂ H ₁₂ , H ₂ B ₁₀ H _10, (NH ₄ ) ₂ B ₁₂ H ₁₂ and (NH ₄ ) ₂ B ₁₀ H ₁₀ . In such systems, no additional catalyst system is needed, although it may be necessary to mix to optimize the hydrogen evolution rate. In this embodiment, the acidic polyhedron borohydride (promoter) is stored separately from the fuel mixture comprising one or more boron hydrides, and the components are combined when needed for hydrogen evolution. The at least one promoter or fuel mixture is preferably an aqueous solution in order to facilitate mixing. However, each component or both components (fuel mixture and promoter) can be stored as a dry powder to eliminate the need for stabilizers. In such cases, a separate water supply is required for hydrogen evolution, and the dry and liquid components are added to the mixing chamber in the defined ratio using all methods known to those skilled in the art. The boron hydride component, concentration and mixing ratio are determined by the present invention as described above so that the ⁺ IC / B ratio of the resulting borate salt is in the range of 0.2 to 0.4 or 0.6 to 0.99. For the purpose of this calculation only, hydronium salts treated with neutral boron hydride, such as H ₂ B ₁₂ H ₁₂ , are treated with B ₁₂ H ₁₄ to determine boron donation. If for the purpose of hydrogen evolution, the promoter is treated with a reactor to mix with the boron hydride fuel mixture and all the required water. Thus, the acidic polyhedral borohydride salt acts as an accelerator to promote the hydrogen evolution reaction, hydrolyzes to produce hydrogen, provides boron atoms in the fuel mixture, and in the case of ammonium salts, provides cations in the fuel mixture.

It was found that the hydrogen gas produced during the hydrolysis reaction elutes with the liquid borate product. In conclusion, in a preferred embodiment, a gas-liquid separator is used to separate hydrogen gas from the effluent solution. In addition, to meet the direct demand of hydrogen gas, it is advisable to incorporate a small buffer tank into the system. In this embodiment, the small buffer tank always contains a reservoir of hydrogen gas for the immediate supply of hydrogen. The drop in pressure that occurs when hydrogen is withdrawn from the buffer tank causes the system to produce more hydrogen gas so that it can maintain a constant concentration of hydrogen gas.

The hydrogen gas produced by the current system can be used as a fuel cell or as a hydrogen consumption mechanism for immediate use. As an alternative method, hydrogen gas may be stored in a gas reservoir or buffer tank as described above for later use.

Fuel mixtures prepared according to the invention are governed by two conditions. The first of these is the molar ratio of the cationic charge ( ⁺ IC) to the boron atoms discussed herein. The second is the relative solubility of each salt used to form the mixture. One of ordinary skill in the art, using the parameters of maximum emptying described herein and the relative solubility of each salt for which the information is readily available, has the maximum ratio and all components are soluble in the aqueous solution. It will be appreciated that phosphorus fuel solutions can be prepared. The calculations are described in the following examples, which are intended to be illustrative and the scope of the invention is not limited thereto.

Example  One

General Process for Generating Hydrogen from Fuel Mixtures

A general description of hydrogen evolution experiments using sodium borohydride, decaborane, sodium hydroxide and water in the fuel mixture as the sample system is described. The fuel mixture was prepared outdoors. Water and stabilized sodium hydroxide were initially mixed and decaborane was added thereto, followed by the appropriate amount of sodium borohydride in the desired proportions.

In order to accelerate and discharge the fuel mixture, a reactor placed on a hot plate was used. The reactor has two thermocouples that act continuously during the movement, one measuring the temperature of the fuel solution and the other measuring the temperature of the head-space near the top of the reactor. Integrate the thermocouple. The second thermocouple regulates a cooling loop that circulates through the reactor that is activated when the second thermocouple records a boundary temperature of 95 ° C. However, in practical terms, even if a hot plate is included, the reaction temperature does not exceed 90 ° C. The pressure sensor continuously measures the internal pressure. The reactor is first charged with six pieces of nickel catalyst coated with ruthenium, each piece ranging from 0.095 to 0.105 g. Approximately 10 grams of fuel mixture (weight already known for each run) was injected through the inlet port and the port was sealed. Then turn on the hotplate. If the pressure is stopped to increase at a significant rate, the hotplate is turned off and the reactor is cooled to room temperature. If the average gas temperature at the top of the reactor corresponds to the average temperature of the reaction solution, data acquisition was stopped and the final pressure was measured. Final pressure and temperature depending on the reactor volume were used to calculate the molar yield of hydrogen gas. The molar output was then compared with the expected output of the amount and concentration of fuel to calculate the percentage output.

The pyrolysis was carried out in the same way as the catalyst outflow, but the Parr reactor was not charged with the catalyst and only the heat of the hotplate was involved in the hydrolysis of the mixture.

Example  2

Hydrogen 7.0 wt -%, ⁺ IC / B ratio = 0.8

Hereinafter, the mixture was mixed by the process of Example 1, the ratio of sodium to boron was 0.8, sodium borohydride 27.16 g, sodium hydroxide 3 g; 100 g of a fuel mixture comprising 3.34 g of decaborane (14) and 66.5 g of water, capable of delivering 7.0% by weight of H2, were obtained. One mole of sodium borohydride produces 4 moles of hydrogen according to equation (1) above.

(1)

(One)

And 1 mole of decabolane (14) produces 22 moles of hydrogen according to equation (2).

(2)

(2)

The hydrogen storage capacity of the mixture is determined by calculating the total moles of H ₂ and dividing by the initial weight of the mixture.

From NaBH ₄

From B ₁₀ H ₁₄

The total hydrogen output is 5.79 + 1.21 = 7 grams or 7% by weight.

⁺ IC: B ratio is calculated as

From NaBH ₄

From B ₁₀ H ₁₄

From NaBH ₄

From NaOH

Thus, the molar ratio of Na: B in the mixture is 0.8.

Example  3

Hydrogen 6.8 wt -%, ⁺ IC / B ratio = 0.25

In the following, it was mixed by the process of Example 1, the ratio of sodium to boron contained 0.25, sodium triborohydride 13.74 g, 13.74 g sodium dodecahydrododecarborate and 76.09 g of water, H ₂ 6.8 weight 100 g of a fuel mixture capable of delivering% were obtained. One mole of sodium dodecahydrododecaborate produces 25 moles of hydrogen according to equation (3) above.

(3)

(3)

And 1 mol of sodium triborohydride produces 9 mol of hydrogen according to Formula (4).

(4)

(4)

The hydrogen storage capacity of the mixture is determined by calculating the total moles of H ₂ and dividing by the initial weight of the mixture.

From Na ₂ B ₁₂ H ₁₂

From NaB ₃ H ₈

The total hydrogen output is 2.87 + 3.93 = 6.8 grams or 6.8 weight percent. In addition, the ⁺ IC: B ratio can be calculated as follows.

From Na ₂ B ₁₂ H ₁₂

From NaB ₃ H ₈

From Na ₂ B ₁₂ H ₁₂

From NaB ₃ H ₈

Thus, the molar ratio of Na: B in the mixture is 0.25.

Example  4

Hydrogen 5 wt -%, ⁺ IC / B ratio = 0.25

Hereinafter, the mixture was mixed by the process of Example 1, the ratio of the metal cation to boron is 0.25, 12.95 g of potassium triborohydride; 100 g of a fuel mixture comprising 6.76 g of magnesium dodecahydrododecaborate and 80.03 g of water, capable of delivering 5.0% by weight of H ₂ , was obtained.

One mole of magnesium dodecahydrododecaborate produces 25 moles of hydrogen according to equation (5) above.

(5)

(5)

And 1 mole of potassium triborohydride produces 9 moles of hydrogen according to equation (6).

(6)

(6)

The hydrogen storage capacity of the mixture is determined by calculating the total moles of H ₂ and dividing by the initial weight of the mixture.

From MgB ₁₂ H ₁₂

From KB ₃ H ₈

The total hydrogen output is 2.05 + 2.95 = 5.0 grams or 5% by weight.

The ⁺ IC: B ratio can also be calculated as

From MgB ₁₂ H ₁₂

From KB ₃ H ₈

From MgB ₁₂ H ₁₂

From KB ₃ H ₈

Thus, the molar ratio of Na: B in the mixture is 0.25.

Example  5-8

The following fuel mixture was prepared according to the process of Example 1 by similar calculations.

Example # Fuel mixture Furtherance ⁺ IC B ⁺ IC / B H wt %   5 3.92 g NaBH ₄ 0.78 g NaOH 0.63 g B ₁₀ H ₁₄ 14.69 H ₂ 0   0.124   0.156   0.79   5.3%   6 6.13 g NaBH ₄ 0.8 g NaOH 0.8 g B ₁₀ H ₁₄ 17.33 H ₂ 0   0.182   0.227   0.8   6.4%   7 7.26 g NaBH ₄ 0.78 g NaOH 0.87 g B ₁₀ H ₁₄ 76.54 H ₂ 0   0.214   0.263   0.81   7.5%   8 3.22 g NaBH ₄ 0.47 g NaOH 0.40 g B ₁₀ H ₁₄ 6.18 H ₂ 0   0.095   0.118   0.81   8.1%

Example  9

Hydrogen 5.6 wt -%, ⁺ IC / B ratio = 0.7

To demonstrate the use of boron hydride as promoter, sodium borohydride (20 mg), diammonium decahydrodecaborate (5 mg) and water (75 mg) were mixed together and performed by direct and powerful hydrogen evolution. . The mixture is equivalent to a fuel mixture with a ⁺ IC ratio to boron of 0.7 and can deliver 5.6 wt-% hydrogen. One mole of sodium borohydride produces 4 moles of hydrogen according to equation (1) above.

(1)

(One)

And 1 mol of diammonium decahydrodecaborate produces 21 mol of hydrogen according to Formula (7).

(7)

(7)

The hydrogen storage capacity of the mixture is determined by calculating the total moles of H ₂ and dividing by the initial weight of the mixture.

From NaBH ₄

The total hydrogen output is 4.26 +1.40 = 5.66 milligrams or 5.6% by weight.

In addition, the ⁺ IC: B ratio can be calculated as follows.

(NH ₄ ) from ₂ B ₁₀ H ₁₀

From NaBH ₄

(NH ₄ ) from ₂ B ₁₀ H ₁₀

From NaBH ₄

Thus, the molar ratio of Na: B in the mixture is 0.70.

Example  10

Hydrogen 7.4 wt -%, ⁺ IC / B ratio = 0.38

According to the process of Example 9, hydrogen was generated by mixing sodium borohydride (17 g), the hydronium salt of B ₁₂ H ₁₂ ^-2 (11 g), sodium hydroxide (3 g) and water (70 g). I was. The mixture is equivalent to a fuel mixture with a ⁺ IC ratio to boron of 0.38 and can deliver 7.4 wt-% hydrogen. One mole of sodium borohydride produces 4 moles of hydrogen according to equation (1) above.

(1)

(One)

And 1 mol of H ₂ B ₁₂ H ₁₂ produces 25 mol of hydrogen according to equation (8).

(8)

(8)

The hydrogen storage capacity of the mixture is determined by calculating the total moles of H ₂ and dividing by the initial weight of the mixture.

From NaBH ₄

From H ₂ B ₁₂ H ₁₂

The total hydrogen output is 3.62 + 3.85 = 7.47 grams or 7.4 wt%.

In addition, the ⁺ IC: B ratio can be calculated as follows.

From H ₂ B ₁₂ H ₁₂

From NaBH ₄

From NaOH

From NaBH ₄

Thus, the molar ratio of Na: B in the mixture is 0.38.

Claims (39)

A slurry of a mixture of boron hydrides containing at least one borohydride salt formed of a cation selected from the group consisting of alkali metals, alkaline earth metals and aluminum cations, or a hydroalcohol solution or an aqueous solution, wherein the mixture of boron hydrides A water-soluble fuel for a hydrogen generator, wherein the ratio of cationic charge ( ⁺ IC) to silver boron is in the range of 0.2 to 0.4 or 0.6 to 0.99. The water-soluble fuel according to claim 1, wherein the mixture of boron hydrides has a ratio of cationic charge ( ⁺ IC) to boron in the range of 0.2 to 0.3 or 0.7 to 0.8. According to claim 1, wherein the boron hydride is borohydride salt (MBH ₄ ), triborohydride salt (MB ₃ H ₈ ), decahydrodecaborate salt (M ₂ B ₁₀ H ₁₀ ) trideca hydrodeca Borate salt (MB ₁₀ H ₁₃ ), Dodecahydrododecarborate salt (M ₂ B ₁₂ H ₁₂ ), Octadecahydroicosaborate salt (M ₂ B ₂₀ H ₈ ) and Decaborate (14) (B ₁₀ H ₁₄ ) A water-soluble fuel selected from the group consisting of M is selected from the group consisting of alkali metals, alkaline earth metals and aluminum. The water-soluble fuel according to claim 1, wherein the mixture of boron hydrides is selected from the group consisting of sodium ions, lithium ions and potassium ions. The method of claim 4, wherein the mixture of boron hydrides further comprises a stabilizer for the borohydride salt in an aqueous medium, the stabilizer comprises a hydroxide selected from the group consisting of sodium hydroxide, lithium hydroxide and potassium hydroxide Water-soluble fuel. 6. The water soluble fuel of claim 5, wherein the borohydride salt is sodium borohydride and the stabilizer is sodium hydroxide. 4. The boron hydride mixture according to claim 3, wherein the boron hydride mixture comprises borohydride salt and decaborane, and the fuel contains a stabilizer for the borohydride salt in an aqueous medium, the stabilizer being sodium hydroxide, lithium hydroxide. And potassium hydroxide selected from the group consisting of potassium hydroxide. 8. The water soluble fuel of claim 7, wherein the boron hydride mixture comprises sodium borohydride and decaborane and the stabilizer is sodium hydroxide. 4. The water-soluble fuel of claim 3, wherein the boron hydride mixture comprises a triborohydride salt and a dodecahydrododecarborate salt. The water-soluble fuel according to claim 9, wherein the triborohydride salt is a potassium triborohydride salt, and the dodecahydrododecaborate salt is a magnesium dodecahydrododecaborate salt. 4. The boron hydride mixture of claim 3, wherein said boron hydride mixture comprises a borohydride salt and a dodecahydrododecaborate salt, said fuel also contains a stabilizer for said borohydride salt in an aqueous medium, said stabilizer being hydroxylated. A water-soluble fuel comprising a hydroxide selected from the group consisting of sodium, lithium hydroxide and potassium hydroxide. The water-soluble fuel of claim 11, wherein the boron hydride salt comprises sodium borohydride, the dodecahydrododecaborate salt is a sodium dodecahydrododecaborate salt, and the stabilizer is sodium hydroxide. 4. The boron hydride mixture is a borohydride salt and a triborohydride salt, the fuel also contains a stabilizer for the borohydride salt in an aqueous medium, the stabilizer being sodium hydroxide, hydroxide. A water-soluble fuel comprising a hydroxide selected from the group consisting of lithium and potassium hydroxide. The water-soluble fuel of claim 13, wherein the borohydride salt is a sodium borohydride salt, the triborohydride salt is sodium triborohydride, and the stabilizer is sodium hydroxide. A mixture of boron hydrides containing at least one borohydride salt formed of a cation selected from the group consisting of alkali metals, alkaline earth metals and aluminum cations; Wherein the ratio of cationic charge ( ⁺ IC) to silver boron is in the range of 0.2 to 0.4 or 0.6 to 0.99, and has a hydrogen generation catalyst selected from the group consisting of acid and transition metal. 16. The method of claim 15, wherein the mixture of boron hydrides has a ratio of cationic charge ( ⁺ IC) to boron in the range of 0.2 to 0.3 or 0.7 to 0.8. The method of claim 15, wherein the borohydride is a borohydride salt (MBH ₄ ), triborohydride salt (MB ₃ H ₈ ), decahydrode carborate salt (M ₂ B ₁₀ H ₁₀ ) trideca hydrodeca Borate salt (MB ₁₀ H ₁₃ ), Dodecahydrododecarborate salt (M ₂ B ₁₂ H ₁₂ ), Octadecahydroicosaborate salt (M ₂ B ₂₀ H ₈ ) and Decaborate (14) (B ₁₀ H ₁₄ ) The hydrogen gas production method of the above, wherein M is selected from the group consisting of alkali metal, alkaline earth metal and aluminum. The method of claim 15, wherein the mixture contains a borohydride salt, wherein M is selected from the group consisting of sodium, lithium, and potassium. 19. The method of claim 18, wherein said mixture further comprises a stabilizer for said borohydride salt in an aqueous medium, said stabilizer comprising sodium hydroxide, lithium hydroxide and potassium hydroxide. The method of claim 15, wherein the catalyst is an acid selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid. The method of claim 1, wherein the catalyst comprises one or more transition metals selected from metals of nickel, cobalt and iron. The method of claim 21, wherein the catalyst is ruthenium, cobalt and mixtures thereof. (a) a slurry of a mixture of boron hydrides containing at least one borohydride salt formed of a cation selected from the group consisting of an alkali metal, an alkaline earth metal and an aluminum cation, or a hydroalcohol solution or an aqueous solution, wherein the boron hydride Mixtures of the present invention are water-soluble fuels for hydrogen generators in which the ratio of cationic charge ( ⁺ IC) to boron is in the range of 0.2 to 0.4 or 0.6 to 0.99, (b) a hydrogen production catalyst selected from the group consisting of acids and transition metals, (c) means for contacting said water soluble fuel with a catalyst to generate hydrogen. 24. The hydrogen generation system of claim 23, wherein said mixture of boron hydrides has a ratio of cationic charge ( ⁺ IC) to boron in the range of 0.2 to 0.3 or 0.7 to 0.8. The method of claim 23, wherein the borohydride is a borohydride salt (MBH ₄ ), triborohydride salt (MB ₃ H ₈ ), decahydrode carborate salt (M ₂ B ₁₀ H ₁₀ ) trideca hydrodeca Borate salt (MB ₁₀ H ₁₃ ), dodecahydrododecaborate salt (M ₂ B ₁₂ H ₁₂ ), octadecahydrocosaborate salt (M ₂ B ₂₀ H ₈ ) and decaborain (14) (B ₁₀ H ₁₄ ) A hydrogen generating system, wherein M is selected from the group consisting of alkali metals, alkaline earth metals and aluminum. The hydrogen generation system according to claim 23, wherein the mixture of boron hydrides contains a borohydride salt formed of a cation selected from the group consisting of sodium ions, lithium ions and potassium ions. The hydrogen generation system of claim 23, wherein the hydrogen generation catalyst is an acid selected from the group consisting of hydrochloric acid, sulfuric acid, and phosphoric acid, and the water soluble fuel is stored in a separate vessel. The method of claim 23, wherein the hydrogen generation catalyst comprises a substrate having transition metal molecules bound, entrapped, and / or coated, wherein the contacting means can move or contact the catalyst with a water soluble fuel. A containment system for said catalyst without said hydrogen generating system. 24. The hydrogen generation system of claim 23, further comprising a gas-liquid separator for separating hydrogen from the effluent. 24. The hydrogen generation system of claim 23, wherein water of at least a portion of the water soluble fuel is obtained from a reaction product of a mechanism that consumes hydrogen, and the apparatus is operably connected to the system. 31. The hydrogen generation system of claim 30, wherein the mechanism for consuming hydrogen is selected from the group consisting of fuel cells, combustion engines, gas turbines, and combinations thereof. (a) a fuel mixture comprising at least one borohydride salt formed of a cation selected from the group consisting of alkali metals, alkaline earth metals and aluminum cations; (b) a promoter comprising an acidic polyhedral borohydride salt selected from the group consisting of hydronium salts and ammonium salts of polyhedron boron hydride, wherein the boron hydride and promoter have a cationic charge ( ⁺ IC) relative to boron ratio of 0.2 to 0.4 Or 0.6 to 0.99,  (c) means for contacting said fuel mixture and water with a promoter to generate hydrogen. 33. The hydrogen generation system of claim 32, wherein the mixture and promoter of boron hydrides has a ratio of positive ion charge ( ⁺ IC) to boron in the range of 0.2 to 0.3 or 0.7 to 0.8. 36. The method of claim 35, wherein the borohydride is a borohydride salt (MBH ₄ ), triborohydride salt (MB ₃ H ₈ ), decahydrodecaborate salt (M ₂ B ₁₀ H ₁₀ ) trideca hydrodeca Borate salt (MB ₁₀ H ₁₃ ), Dodecahydrododecarborate salt (M ₂ B ₁₂ H ₁₂ ), Octadecahydroicosaborate salt (M ₂ B ₂₀ H ₈ ) and Decaborate (14) (B ₁₀ H ₁₄ ) A hydrogen generating system, wherein M is selected from the group consisting of alkali metals, alkaline earth metals and aluminum. 33. The hydrogen generation system of claim 32, wherein said promoter is H ₂ B ₁₂ H ₁₂ . 33. The hydrogen generation system of claim 32, wherein said promoter is (NH ₄ ) ₂ B ₁₀ H ₁₀ . 33. The hydrogen generation system of claim 32, wherein said mixture of boron hydrides contains a borohydride salt formed of a cation selected from the group consisting of sodium, lithium and potassium. 33. The hydrogen generation system of claim 32, wherein at least some of the water is obtained from the reaction product of a mechanism that consumes hydrogen, the apparatus being operably connected with the system. 39. The hydrogen generation system of claim 38, wherein the mechanism for consuming hydrogen is selected from the group consisting of fuel cells, combustion engines, gas turbines, and combinations thereof.