WO2009009853A1

WO2009009853A1 - Hydrogen system

Info

Publication number: WO2009009853A1
Application number: PCT/CA2007/001230
Authority: WO
Inventors: Boyd Davis; Chih-Ting Flora Lo; Kunal Karan
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-07-17
Filing date: 2007-07-17
Publication date: 2009-01-22
Anticipated expiration: 2010-01-17

Abstract

A system for generation of hydrogen comprising a hydrogen generation reactor; a reactor inlet; a reactor outlet; water; at least one metal hydride of the formula M(BH4)X, wherein M is an element selected from a group consisting of groups 1 and 2 of the periodic table, B is an element selected from a group consisting of group 13 of the periodic table, H is hydrogen, and x is a positive integer; and at least one alcohol of formula R-OH, wherein R is an alkyl group. The ratio of water to total dissolved hydride is from about 3.0: 1 to about 0.05: 1, and the ratio of alcohol to total dissolved hydride is from about 5: 1 to about 100: 1. The hydrogen generation system is used as a source of hydrogen for fuel cells.

Description

HYDROGEN SYSTEM

TECHNICAL FIELD

The field of the invention relates to hydrogen storage, generation and power systems. In particular, the field of the invention relates to water/alcohol/chemical hydride systems.

BACKGROUND ART

Solid chemical hydrides such as sodium borohydride, NaBH₄, can be used in hydrogen generation reactions. Hydrogen can be released by reacting the hydride with other reactants. For example, hydrogen can be generated by alcoholysis, such as methanolysis, as shown in equation A.

NaBH₄ + 4CH₃OH = Na(BOCH₃)₄ + 4H₂ (A)

This technique does not provide large overall system storage densities, however, because the hydrogen available for reaction from methanol is low relative to its molar mass. The nominal density is only 4.8 wt% when the storage capacity is calculated by dividing the weight of the four moles of hydrogen produced by the total weight of the reactants: one mole of sodium borohydride and four moles of methanol, according to equation B:

(4 x 2) / (37.8 + 4 X 32) = 4.8 wt% (B)

Alternative methods release hydrogen by reacting the chemical hydride with reactants such as water. For example, theoretically, hydrogen can be generated by hydrolysis according to equation C.

NaBH₄ + 2 H₂O = NaBO₂ + 4 H₂ (C)

The storage capacity is calculated by dividing the weight of four moles of hydrogen by the total weight of one mole of sodium borohydride and two moles of water according to equation D:

(4 x 2) / (37.8 + 2 X 18) = 10.8 wt % (D)

This technique does not efficiently release hydrogen. Earlier hydrogen generation work using water or steam reactions with solid borohydride reactant concluded that solid state sodium borohydride creates mass transport problems.

The reaction between water and borohydride solids promotes formation of hydrated sodium borate, NaBO₂.4H₂O. The actual reaction with sodium borohydride is described in Equation E.

NaBH₄ + 6HO = NaBO₂.4H₂O + 4H (E)

This creates problems because hydrated sodium borate dissolved in aqueous solutions readily precipitates, adhering to system components such as reactors, tubing walls, and catalysts. The precipitate generally hinders operation and maintenance. Excess water is necessary to drive the hydrogen generation reaction to completion. The hydrogen generation reaction can only reach completion where excess water also hydrates the sodium borate product to address precipitation.

Additional water can be stored on-board to maintain the hydrated sodium borate in solution and prevent precipitation. In that case, the total amount of water needed must both react with NaBH₄ and dissolve the by-product NaBO₂.4H₂O. Other problems arise, however, when NaBO₂.4H₂O is maintained in solution. Its low solubility in low temperature aqueous solutions is one example. The storage requirements of the additional water on-board will also reduce the overall system storage density.

The sheer volume of the hydrated sodium borate is another concern because four moles of water attach to each mole of sodium borate when hydration takes place. Storage volume requirements for hydrated sodium borate also add to the total system and its density, reducing the overall volumetric storage density of hydrogen in the system. Problems with hydrated borate formation are well known. See, e.g., Shang, Y. & Chen, R. Hydrogen Storage via the Hydrolysis of NaBH4 Basic Solution: Optimization of NaBH₄ Concentration. Energy & Fuels, 2006, 20, 2142-2148). An improved system is desired.

DISCLOSURE OF INVENTION

There is provided a system comprising a hydrogen generation reactor, a reactor inlet, a reactor outlet for controlling output, water, at least one chemical hydride of formula M(BH4)_X, wherein M is an element selected from a group consisting of groups 1 and 2 of the periodic table, B is an element selected from a group consisting of group 13 of the periodic table, H is hydrogen, and x is a positive integer; at least one alcohol of formula R-OH, wherein R is an alkyl group, and wherein a water: total dissolved hydride ratio is suitable for theoretical hydrolysis of total dissolved hydride, and an alcohol: total dissolved hydride ratio is suitable for pseudo-first order alcoholysis of total dissolved hydride.

In another aspect, the system further comprises a stabilizer for stabilizing the at least one hydride with a member selected from the group consisting of the water and the alcohol. In another aspect, the system further comprises at least one catalyst. In another aspect, the system further comprises a catalytic content including a base metal. In another aspect, the system further comprises a catalytic content including at least one element selected from the group consisting of copper, iron, nickel, and cobalt. In another aspect, the system further comprises a precious metal catalytic content that is negligible. In another aspect, the system further comprises a catalyst structure including at least one member selected from the group consisting of metal mesh, metal foam, beads, and coated substrates. In another aspect, the system further comprises a total dissolved hydride conversion in the range from about 100% to about 10%. In another aspect, the system further comprises a total dissolved hydride conversion in the range from about 100% to about 1%. In another aspect, water is reactive with a compound of formula M( (BO-R)₄)_x according to M( (BO-R)₄)_x + 2_X(H₂O) = M(BO₂)_x + 4x(R- OH). In another aspect, the system further comprises alcohol: total dissolved hydride ratio from about 5:1 to about 100:1. In another aspect, the system further comprises alcohol: total dissolved hydride ratio from about 7:1 to about 50:1. In another aspect, the system further comprises alcohol: total dissolved hydride ratio of about 10:1. In another aspect, the system further comprises water: total dissolved hydride ratio from about 3.0:1 to about 0.05:1. In another aspect, the system further comprises water: total dissolved hydride ratio from about 2.5:1 to about 0.5:1. In another aspect, the system further comprises water: total dissolved hydride ratio from about 2.1 to about 1.5:1. In another aspect, the system further comprises water: total dissolved hydride ratio from about 2.0:1. In another aspect, the water is at least one member selected from the group consisting of off board supplied water and fuel cell recovered water. In another aspect, the water is fuel cell recovered water. In another aspect, the water is supplied together with the alcohol. In another aspect, the alcohol is at least one member selected from the group consisting of off board supplied alcohol, depleted reactor solution, and depleted reactor solution recovered alcohol. In another aspect, the alcohol is at least one member selected from the group consisting of the depleted reactor solution and the depleted reactor solution recovered alcohol. In another aspect, at least one hydride is at least one member selected from the group consisting of off board supplied hydride, the depleted reactor solution, and the depleted reactor solution recovered hydride. In another aspect, at least one hydride is at least one member selected from the group consisting of depleted reactor solution and depleted reactor solution recovered hydride. In another aspect, the system further comprises a storage chamber for supplying the reactor. In another aspect, the storage chamber includes at least one dissolved hydride and alcohol. In another aspect, the storage chamber includes at least one solid hydride. In another aspect, the storage chamber supplies the reactor with at least one dissolved hydride. In another aspect, the system further comprises at least one supplemental storage chamber for supplying the reactor with at least one member selected from the group consisting of the water and the alcohol. In another aspect, the system is continuous. In another aspect, the system further comprises at least two passes. In another aspect, the reactor is a catalytic reactor.

In another aspect, a single pass total dissolved hydride conversion is from about 100% to about 10%. In another aspect, single pass total dissolved hydride conversion is from about 100% to about 1%. In another aspect, the system further comprises a process control including variable conversion rates. In another aspect, the system total storage density is independent from the single pass total dissolved hydride conversion. In another aspect, at least one chemical hydride includes sodium borohydride. In another aspect, at least one alcohol includes methanol.

In another aspect, the system produces hydrogen for about 100 hours. In another aspect, depleted solution is recycled to the reactor. In another aspect, hydrogen production is 3.4 grams. In another aspect, power production is 1 Watt. In another aspect, alcohol is methanol, methanol content is 20 ml, sodium borohydride content is 15.9 grams, water content is 15.2 grams, sodium hydroxide content is 5 percent by weight, catalyst is Ru- Al₂O₃ pellets, and temperature is about 20 degrees Celsius. In another aspect, water is supplied on board and the total system density excluding equipment weight is 7.1 percent by weight. In another aspect, water is supplied from a fuel cell and the total system density excluding equipment weight is 10.5 percent by weight. In another aspect, hydrogen production is 10.1 grams. In another aspect, power production is 3 Watts. In another aspect, alcohol is methanol, methanol content is 30 ml, sodium borohydride content is 47.7 grams, water content is 45.5 grams, sodium hydroxide content is 5 percent by weight, the catalyst is Ru-Al₂O₃ pellets, and temperature is about 20 degrees Celsius. In another aspect, water is supplied on board and the total system density excluding equipment weight is 8.5 percent by weight. In another aspect, water is supplied on board and the total system density including system equipment weight of 100 grams is 4.7 percent by weight. In another aspect, water is supplied from a fuel cell and the total system density including system equipment weight of 100 grams is 6.0 percent by weight.

In another aspect, alcohol is methanol, methanol content is 20 ml, sodium borohydride content is 47.7 grams, water content is 45.5 grams, sodium hydroxide content is 5 percent by weight, the catalyst is Ru-Al₂O₃ pellets, and temperature is about 20 degrees Celsius. In another aspect, water is supplied from a fuel cell and the total system density excluding equipment weight is 14.9 percent by weight.

In another aspect, the system produces hydrogen for about 50 hours. In another aspect, depleted solution is recycled to the reactor. In another aspect,—hydrogen production rate is 10 ml/minute. In another aspect, alcohol is methanol, methanol content is 200 ml, sodium borohydride content is 13.1 grams, water content is 13.0 grams, sodium hydroxide content is 7.9 grams, catalyst is Ru-Al₂O₃, and temperature is about 20 degrees Celsius .

In another aspect, hydrogen is produced for about 42 hours. In another aspect, depleted solution is recycled to the reactor. In another aspect, hydrogen production rate is 11 ml/minute. In another aspect, alcohol is methanol, methanol content is 50 ml, sodium borohydride content is 15.0 grams, water content is 14.1 grams, sodium hydroxide content is 7.9 grams, catalyst is Ru- Al₂O₃, and temperature is about 20 degrees Celsius.

In another aspect, hydrogen is produced for about 8 hours. In another aspect, hydrogen production rate is 20 ml/min. In another aspect, alcohol is methanol, methanol content is 200 ml, sodium borohydride content is 33.0 grams, water content is 30.3 grams, sodium hydroxide content is 23.6 grams, catalyst is Ru-SiO₃, and temperature is about 20 degrees Celsius. In another aspect, hydrogen is produced for about 150 minutes. In another aspect, hydrogen production rate is 10 ml/min. In another aspect, alcohol is methanol, methanol content is 50 ml, sodium borohydride content is 6.4 grams, water content is 6.1 grams, sodium hydroxide content is 2.0 grams, catalyst is Ru-SiO₃, and temperature is about 20 degrees Celsius. In another aspect, hydrogen is produced for about 14.5 minutes. In another aspect, hydrogen production rate is 23 ml/min. In another aspect, alcohol is methanol, methanol content is 30 ml, sodium borohydride content is 0.8 grams, water content is 0.8 grams, sodium hydroxide content is 1.1 grams, catalyst is Ru-Al₂O₃, and temperature is about 0 degrees Celsius. In another aspect, hydrogen is produced for about 18 hours. In another aspect, hydrogen production rate is 5 ml/min. In another aspect, alcohol is methanol, methanol content is 100 ml, sodium borohydride content is 6.1 grams, water content is 0.006 ml/min, sodium hydroxide content is 4.0 grams, catalyst is Ru-SiO₃, temperature is about 20 degrees Celsius. In another aspect, hydrogen is produced for an additional about 50 hours. In another aspect, hydrogen production in the additional about 50 hours is varied from earlier production. In another aspect, hydrogen production in the additional 50 hours is 1.5 ml/min.

In another aspect, hydrogen is produced for about 400 minutes. In another aspect, hydrogen production rate is 0.0008 ml/min. In another aspect, alcohol is methanol, methanol content is 18 ml, sodium borohydride content is 0.038 grams, water content is 0.036 grams, and temperature is about 0 degrees Celsius.

In another aspect, hydrogen is produced for about 12 hours. In another aspect, hydrogen production is 0.003 ml/min. In another aspect, alcohol is methanol, methanol content is 18 ml, sodium borohydride content is 0.4 grams, water content is 0.038 grams, and temperature is about minus 20 degrees Celsius. In another aspect, hydrated borate formation is inhibited. In another aspect, at least one controller controls a supply for at least one member selected from the group consisting of the off board supplied hydride, the off board supplied alcohol, the off board supplied water, the depleted reactor solution, the depleted reactor solution recovered hydride, the depleted reactor solution recovered alcohol, and the fuel cell recovered water. In another aspect, the system further comprises a fuel cell for receiving hydrogen fuel. In another aspect, the system further comprises a PEM fuel cell stack for receiving hydrogen fuel. In another aspect, electric output from the fuel cell stack is sent to an electric motor. In another aspect, fuel cell generated water is supplied to at least one member of the group consisting of an anode, a reactant heater, an alcohol vapour stripper, a water storage chamber, an exhaust outlet. In another aspect, the system further comprises a cold start-up unit for generating hydrogen by catalytic alcoholysis of the at least one hydride. In another aspect, a cold start-up unit releases heat to the system and shuts down when a set point temperature is reached. In another aspect, the system supplies hydrogen to fuel cell applications in confined environments. In another aspect, the system supplies hydrogen to fuel cell applications for portable devices. In another aspect, the system supplies hydrogen to fuel cell applications for automotive devices. In another aspect, the system start-up ambient operating temperature is from about minus 50 to about 60 degrees Celsius.

Other embodiments and advantages may be ascertained by reviewing the description and drawings .

BRIEF DESCRIPTION OF DRAWINGS

The present invention is further described in the detailed description and referenced to the noted drawings, being non- limiting examples of exemplary embodiments, wherein:

Figure 1 illustrates one embodiment of the invention as a constant volume batch reactor system for hydrogen generation from chemical hydride, water, and alcohol.

Figure 2a illustrates a front view of an alternate design for the reactor in Figure 1.

Figure 2b illustrates a side view of the reactor in Figure 2b.

Figure 3 illustrates another embodiment of the invention as a fuel cell system incorporating hydrogen production.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention provides a system of hydrogen storage and production using chemical hydride in the presence of water. A system using hydrogen production together with a fuel cell is also provided.

Hydrogen is produced in the presence of water, but typical associated production of density-decreasing by-products such as hydrated sodium borate is reduced. Equipment function is maintained and the process can be flexibly arranged. Hydrogen can be removed, and other products such as anhydrous sodium borate can be removed from the system as desired.

In general, the system comprises contacting a chemical hydride with alcohol and water to form hydrogen and by-products. This promotes conversion of water to form hydrogen, or anhydrous borate and alcohol, according to reaction temperature, and reduces water available for conversion to hydrated borate.

Hydrated borate formation can be inhibited by contacting chemical hydride with alcohol and water, wherein an alcohol: total dissolved hydride ratio is suitable for pseudo-first order alcoholysis and a water: total dissolved hydride ratio is suitable for theoretical hydrolysis. The hydride can be contacted with alcohol and water in combination, or in sequence.

Available hydrides are represented by the formula M(BH₄)_X, where M is an element selected from a group consisting of groups 1 and 2 of the periodic table, B is an element selected from a group consisting of group 13 of the periodic table, H is hydrogen, and x is a positive integer. Example hydrides include: NaBH₄, LiBH₄, Mg (BH₄) ₂, KBH₄ and combinations.

Available alcohols are represented by the formula R-OH, wherein R is an alkyl group. Examples include CH₃OH, C₂H₅OH, C₃H₇OH, C₄H₉OH, and combinations. Where alcoholysis occurs, water reacts with the alcoholysis by-product, M((BO-R)₄)_X, according to equation F.

M( (BO-R)₄)_x + 2_X(H₂O) = M(BO₂)_x + 4x(R-0H) (F)

For example, in equation A above where the alcohol is methanol, CH₃OH, and the alcoholysis by-product is sodium tetramethoxyborate , NaB(OCH₃)₄, water reacts with the by-product according to Equation G.

Na(BOCH₃) + 2 H₂O = NaBO₂ + 4CH₃OH (G)

Water available for conversion to hydrated borate is reduced, and "runaway" hydration producing hydrated borate is controlled. Excess water typically required for dissolution of hydrated by- product is not necessary, and system storage density can be improved.

The alcohol: total dissolved hydride ratio suitable for pseudo- first order alcoholysis is a ratio from about 5:1 to about 100:1; preferably from about 7:1 to about 50:1; and more preferably from about 10:1.

The water: total dissolved hydride ratio suitable for theoretical hydrolysis is a ratio from about 3.0:1 to about 0.05:1; preferably from about 2.5:1 to about 0.5:1; more preferably from about 2.1 to about 1.5:1; and more preferably from about 2.0:1.

When products are formed, hydrogen is separated from the depleted solution and collected using separation techniques such as filtration. (Here, "depleted solution" or "depleted reactor solution" means materials that were subjected to reaction at least once. These materials may contain unreacted materials, including dissolved hydride, and inert materials.)

After hydrogen separation, some or all of the depleted solution can be returned to the reactor, without treatment, for further reaction if desired. The reactor contents (with depleted solution) can be subjected to further reaction. If desired, a portion of the depleted solution can be separated from the depleted solution that is sent back to the reactor. The water can be provided at a water: total dissolved hydride ratio suitable for theoretical hydrolysis by ratio controller or other mechanisms known in the field.

Solid chemical hydride can be stored in saturated solution located in storage chambers, or in the reactor with the reactants where such storage does not compromise reactor function. (It is understood that the saturation point of the saturated solution is reached when dissolved hydride solute crystallizes from solution at the same rate at which it dissolves.) Sodium borohydride can be loaded to the solubility limit, then additional quantities can be stored as solids to provide feed storage and increase storage capacity. These additional solids are available for use in continuous operation, if desired, since they dissolve and replenish the sodium borohydride consumed from solution. Additional sodium borohydride can be supplied to the system after the initial load is consumed, or earlier as desired. A hydride stabilizer can be added if desired.

Alcohol levels available to the reactor can be maintained at an alcohol: total dissolved hydride ratio suitable for pseudo-first order alcoholysis by, for example, returning depleted solution containing alcohol to the reactor. Where portions of the depleted solution are separated therefrom, alcohol can be recovered from the portion by filtration or otherwise and redirected to the reactor if desired. Where return of depleted solution is not desired, alcohol levels can be maintained by reloading to the system otherwise.

Since hydrogen can be produced in the presence of water but production of hydrated sodium borate or other hydrated byproduct is reduced or eliminated, equipment function is improved and the process can be more flexibly arranged.

Example 1 is an illustrative example of alcoholysis-like kinetic behaviour and controlled hydration for pseudo-first order hydrogen generation reaction systems containing water.

Example 1 ;

A constant volume batch reactor was used to monitor hydrogen generation from sodium borohydride and water between -20 and +50 °C in excess solvent (here, anhydrous methanol, 99.5+% purity, water content less than 50 ppm, Fisher Scientific Canada™) .

Figure 1 illustrates the modified 100 ml three-neck flask reactor (1). A first neck with digital temperature reader (2) monitored the temperature via a thermocouple (3) housed in a 1/4" closed end glass tubing inserted into the flask through an 0-ring. A second neck delivered sodium borohydride to the reactor via a modified stopcock (4). A third neck with valve 1 (5), a valved two-way glass fitting connected to 1/4" PVC tubing directed product hydrogen gas into a inverted 250 ml graduated cylinder (6) for volumetric analysis. This third neck was also used for purging argon gas , Ar ( 7 ) . The inverted graduated cylinder ensured that the vapour phase volume change in the product stream was attributed to pure hydrogen. Water placed in the cylinder effectively absorbed any methanol vapour entering therein.

The stopcock was weighed before and after the tests to calculate sodium borohydride in the system. Anhydrous methanol was measured in an amount approximately 100 times the amount required for theoretical methanolysis of sodium borohydride. A quantity of distilled water twice the number of moles of sodium borohydride was measured, then injected into the anhydrous methanol. This solution was poured into the reactor through the open third neck. The neck was sealed and 1/4" PVC tubing was connected to a glass outlet extending therefrom. The other end of the tubing was disconnected from inside the inverted graduated cylinder to set up the purging period.

The reactor was insulated in an insulated recirculating tube (9) and immersed in a temperature controlled heating/cooling fluid (10) in an open top styrofoam container. The container was placed on a mechanical stirrer (11) and a chiller/heater (12) connected to the insulated recirculating tube set the recirculating heating/cooling fluid temperature. The 250 ml graduated cylinder was filled with water (13) and placed in a room temperature water bath (14). A magnetic stirrer (15) was activated at medium level. A 20 minute low flow rate argon gas purge minimized moisture content in the system. After system temperature stabilized, argon flow was stopped and valve 1 on the third neck was turned to permit product gas exit via the PVC tubing. The open end of the PVC tubing was inserted in the inverted graduated cylinder and the initial level of distilled water therein was recorded.

The reaction commenced when sodium borohydride was released into the reactor from the modified stopcock hole. The gas phase volume change in the inverted graduated cylinder was recorded as a function of time. The reaction was determined to have reached completion when the volume displaced in the graduated cylinder matched the theoretical amount of hydrogen generated according to the ideal gas law. In trials where a small amount of powder remained in the stopcock, the reaction was determined to reach completion when the graduate cylinder volume remained constant for more than 30 minutes.

After reaction completion, reactor contents were transferred to a vacuum flask, dried under argon, and analytically analyzed using techniques including x-ray diffractometry.

Gas captured in the graduated cylinder was confirmed as pure hydrogen by connecting the cylinder to a second reactor filled with methanol and heating to 50 °C for one hour. Since methanol has lower vapour pressures at temperatures below 50 °C and no gas phase volume change occurred in the inverted graduated cylinder, all methanol evaporated from the reactor during testing was absorbed by water in the inverted graduated cylinder.

Reaction by-product analyses detected anhydrous sodium borate and sodium tetramethoxyborate , depending on the test temperature conditions. The final product was easily removed and did not adhere to the reactor, further indication that anhydrous sodium borate was present. Hydrated sodium borate was not detected. The conversion data was further processed using the mole balance equation of sodium borohydride for a pseudo-first order constant volume batch reactor. The pseudo-first order model accounted for the difference between system concentrations of the hydride and the alcohol. See equation H below.

d[NaBH₄]/dt = -IC[NaBH₄] (H)

Note that k' is the pseudo-first order rate constant proportional to the concentration of methanol present at startup, of the disappearance of sodium borohydride, with units in reciprocal seconds. The real second order rate constant, k, is related to k' according to k'=k[CH₃OH]₀, where [CH₃OH]₀ is the concentration of methanol present at start-up. The real second order rate constant is k'=k[CH₃OH].

Regression analyses provided rate constants for reactions at corresponding temperatures . Natural logarithms of the rate constants were plotted as a function of reciprocal temperature using the linearized Arrhenius equation in equation I.

ln(k) = -Ea/RT + In(A) (I)

Note that Ea is the activation energy, R is the rate constant, T is the temperature of the reaction, and A is the pre-exponential factor.

Activation energies and pre-exponential factors for the hydrogen generation reactions were obtained from the slopes and the y- intercepts. Confidence limits corrected for the natural logarithm were used as final values for the error analysis. The mean of the natural logarithm of rate constants was calculated for respective temperatures, then the standard deviation and the confidence limit were obtained based on a 95% confidence interval .

All solvent systems exhibited first order rate behaviour, and the kinetic behaviour of the sodium borohydride: water/methanol system was similar to that of the sodium borohydride: methanol system at all test temperatures. It was dissimilar to a sodium borohydride: water aqueous test system. (Here, "similar" means the activation energies and rate constants found in the compared systems are within the confidence limits obtained based on a 95% confidence interval.)

Many designs are available since the system remains capable of further reaction after the reaction, and stable feed supply and re-usable depleted solution are available. Batch or high conversion single pass reaction processes are not required because continuous multiple pass operations and variable reaction conversion rates can be achieved with improved unit operations and feed supply. Catalyst designs can be modified for lower conversion rates, and conversion rate control can rely thereon, and not solely on additional flow rate control.

Because single pass high conversion reactions are not the focus, design criteria can consider the number of catalysts in the systems, as well as their related costs, quantity, and other characteristics. In non-recycle applications, homogeneous catalyst selection is also expanded and improved.

The following examples illustrate flexible designs for hydrogen production. Examples 2 to 7 were conducted at room temperature using catalysts and recycle. Examples 2 to 6 were conducted using water in the feed. Example 7 was conducted using separate water feed. Examples 2 to 7 were conducted using sodium borohydride in the feed with sodium borohydride solids in the chamber. Example 7 was conducted using sodium borohydride in the feed without solids in the chamber. Examples 8 and 9 were conducted at low temperature using no catalysts and no recycle.

Example 2

In a continuous reaction at 20 °C, a mixture of 13.1 g (6.8 wt%) NaBH₄ in 200 ml CH₃OH with 7.9 g (4 wt%) NaOH, was mixed with the theoretical amount of water, 13.0 g. Solid borohydride was placed in the bottom of the chamber at the beginning of the experiment. A mixture flow rate of 10 ml/min (water flow rate of 0.165 ml/min included) was passed through a downflow catalytic reactor loaded with 6.9 g of 2 wt% Ru on 1/8" cylindrical Al₂O₃ support. A minimum stable hydrogen generation rate of 10 ml/min was recorded for 50 hours. The depleted fuel was recycled and reused. Over time, the quantity of solid NaBH₄ decreased and white powdery precipitate of NaBO₂ formed.

Example 3

In a continuous reaction at 20 °C, a mixture of 15.0 g (7.7 wt%) NaBH₄ in 50 ml CH₃OH with 7.9 g (4 wt %) NaOH, was mixed with the theoretical amount of water, 14.1 g. Solid borohydride was placed in the bottom of the chamber at the beginning of the experiment. A mixture flow rate of 8 ml/min (water flow rate of 0.585 ml/min included) was passed through a downflow catalytic reactor loaded with 6.2 g of 2 wt% Ru on 1/8" cylindrical Al₂O₃ support. A minimum stable hydrogen generation rate of 11 ml/min was recorded for 42 hours. The depleted fuel was recycled and reused. Over time, the precipitate of NaBH₄ decreased and white powdery precipitate of NaBO₂ was observed.

Example 4

In a continuous reaction at 20 °C, a solution of 33.0 g (13.4 wt%) NaBH₄ in 200 ml CH₃OH with 23.6 g (7.5 wt%) NaOH, was mixed with the theoretical amount of water, 30.3 g. Solid borohydride was placed in the bottom of the chamber at the beginning of the experiment. A mixture rate of 1 ml/min (water flow rate of 2.6*10^'3 ml/min included) was passed through a downflow catalytic reactor loaded with 7.5 g of 2 wt% Ru on 1/8" cylindrical Al₂O₃ support. The conversion of the reaction achieved the minimum rate of 35% of theoretical (hydrogen generation rate of 79 ml/min) within the first few (3) minutes, then dropped to a minimum stable 15% conversion (hydrogen generation rate of 20 ml/min) for the next 8 hours. The depleted fuel was recycled and reused. Over time, the precipitate of NaBH₄ decreased and white powdery precipitate of NaBO₂ was observed.

Example 5

In a continuous reaction at 20 °C, a solution of 6.4 g (8 wt% ) NaBH₄ in 50 ml CH₃OH with 2 g (4 wt%) NaOH, was mixed with the theoretical amount of water, 6.1 g, and passed through a downflow catalytic reactor loaded with 2.0 g of 2 wt% Ru on irregular shaped high surface area Al₂O₃ support at the flow rate of 0.66 ml/min (water flow rate of 6.2*10^~4 ml/min included). The minimum stable hydrogen generation rate reached a maximum of 23 ml/min (35% theoretical conversion) within one minute but subsequently dropped to approximately 10 ml/min (20% conversion) for the next 150 minutes. The depleted fuel was recycled and reused.

Example 6

In a continuous reaction at 20 °C, a solution of 0.8 g (3.4 wt%) NaBH₄ in 30 ml CH₃OH with 1.1 g (5 wt%) NaOH was mixed with the theoretical amount of water, 0.8 g. A mixture flow rate of 0.375 ml/min (water flow rate of 5.7*10^~6 ml/min included) was passed through a downflow catalytic reactor loaded with 1.9 g of Ru on ion exchange resin bead. The minimum stable hydrogen generation rate reached 23 ml/min (100% theoretical conversion) in 2 minutes, decreased to 15 ml/min (65% conversion) in 8 minutes, then increased to 23 ml/min (100% conversion) at 14.5 minutes, when catalyst destruction due to volume expansion of ion exchange resin beads in methanol (100%) was recorded.

Example 7

In a continuous reaction at 20 °C, a mixture of 6.1 g (7.7 wt% ) NaBH₄ in 100 ml CH₃OH with 4.0 g (5 wt%) NaOH and solid borohydride was placed in the bottom of the chamber at the beginning of the experiment. The solution was passed through an upflow catalytic reactor loaded with 2.0 g of 2.7 wt% Ru on 1/16" cylindrical SiO₂ extrudate support at the flow rate of 4 ml/min. Water was injected via a syringe pump at the rate of 0.006 ml/min, the theoretical amount. A minimum stable hydrogen generation rate of 5 ml/min was recorded for 18 hours. The rate then dropped to approximately 1.5 ml/min for another 50 hours. The depleted fuel was recycled and reused, and the NaBH₄ solids decreased over time. White powdery precipitate of NaBO₂ was observed overnight.

Example 8

In a batch reaction at 0 °C, 0.038 g of NaBH₄ was dropped into a mixture of 18 ml CH₃OH and theoretical amount of water, 0.036 g. The reaction reached completion in approximately 400 minutes, with a minimum stable hydrogen generation rate of 0.0008 ml/min during the exponential phase.

Example 9

In a batch reaction at -20 °C, 0.04 g of NaBH₄ was dropped into a mixture of 18 ml CH₃OH and theoretical amount of water, 0.038 g. The reaction was extremely slow with a minimum conversion of 2%, or approximately 2 ml, in 12 hours, for a rate of 0.003 ml/min during the exponential phase.

7* 0 6.6 18 0.038 0.036 - - 400 min @

0.0008

8* -20 12 18 0.04 0.038 - - 12 hr @

0.003 Note: * batch reaction

The examples 2 to 9 summarized in Table 1 are merely a selection of illustrative designs that can be used to contact the reactants for hydrogen generation, and the range of available designs facilitates many applications. For example, the solid chemical hydride can be provided for contact via controller such as the pellet dispenser inlet (100) at Fig. 2. (The thermocouple neck (102) and purge gas/hydrogen outlet neck (104) are also shown in example orientation). Other examples include a pre- mixed cartridge chamber of saturated solution, and other variations.

Hydrogen generation rates less than 100 ml/min (for example, 1.5 ml/min) can be provided for extended periods where the continuous operation conditions are met. Fuel cell applications can be designed to address specific needs in confined environments including, for example, submersible, mining/underground, and other enclosed or substantially enclosed environments. Low temperature and portable applications are possible. Where higher hydrogen generation rates are required for applications such as hydrogen refueling stations, or for large power usage in the kilowatt range or otherwise, applications can meet these needs as well.

Hydrogen storage density will depend in part on the weight of auxiliary equipment required by the system. Where water is supplied from outside the system, densities exceed those of comparable systems supplied from on-board water storage chambers. System density decreases when additional storage chambers are required for reactants, products, or both. On the product side, it is understood that additional product storage chambers can be downsized or eliminated, depending on the system, where additional filtration devices or other equipment control on-board alcohol content. Although these increase the overall weight, improved retention can be achieved. The large quantity of alcohol available for pseudo-first order rate reactions will assist here.

The system density also decreases when on-board customized equipment is required. Single pass systems with high conversion catalysts can require such customization. In contrast, designs consistent with the present subject matter decrease dependence on single pass conversion and can rely on standard equipment instead, according to the particular application. Although specialised applications with specific requirements will remain i for example, small hydrogen flow rates), flexible design considerations associated with the subject matter herein permit use of standard-sized pumps and other equipment. This reduces comoonent weight and improves total system density. Example systems with densities follow.

Example 10: 1 Watt system. 100 hours operation

Total amount of methanol is 20 ml . NaOH IR 5 wt% of methanol solution. sodium borohydride required is 15.9 g, and water required is 15.2 g. Water in this system is stored onboard. The hydrogen produced is 3.4 g (40.4 L at standard condition). The storaσe densitv is: 3.4/ f 15.9+15.2+20* .79+0.05*20*0.79 ) = 7.1

Example 11: 1 Watt system, 100 hours operation

Total amount of methanni is 20 ml , NaOH is 5 wt% of methanoll solution. sodium borohydride required is 15.9 σ, and water required is 15.2 g. Water in this system is recycled from the fuel cell. The fuel cell can make 30.3 g of water and a 50% water recycle rate is assumed. The hydroσen nroduced is 3.4 g (40.4 L at standard condition). The storage density is: 3.4/ (15.9+20*.79+0.05*20*0.79)= 10.5 wt% . Example 12: 3 Watt system, 100 hours operation

Total amount of methanol is 30 ml, NaOH is 5 wt% of methanol solution, sodium borohydride required is 47.7 g, and water required is 45.5 g. Water in this system is stored onboard. The hydrogen produced is 10.1 g (121.3 L at standard condition). The storage density is: 10.1/ ( 47.7+45.5+30* .79+0.05*30*0.79 )= 8.5 wt%.

Example 13: 3 Watt system, 100 hours operation

Total amount of methanol is set to be 20 ml, NaOH is 5 wt% of methanol solution, sodium borohydride required is 47.7g_, and water required is 45.5 g. Water in this system is recycled from the fuel cell. The fuel cell can make 91.0 g of water and a 50% water recycle rate is assumed. The hydrogen produced is 10.1 g (121.3 L at standard condition). The storage density is: 10.1/(47.7+30*.79+0.05*30*0.79)= 14.9 wt%.

Example 14: 3 Watt system, 100 hours operation

Total amount of methanol is set to be 30 ml, NaOH is 5 wt% of methanol solution, sodium borohydride required is 47.7 g, and water required is 45.5 g. Water in this system is stored onboard. The hydrogen produced is 10.1 g (121.3 L at standard condition) . The system includes a plastic solvent/borohydride storage system, a stainless steel catalytic reactor with 10 g Ru-based catalysts, a filtration unit, and a plastic storage chamber for filter cake. The weight of the system is assumed to be 100 g. The storage density is: 10.1/(47.7+45.5+30*.79+0.05*30*0.79+100)= 4.7 wt%.

Example 15: 3 Watt system, 100 hours operation

Total amount of methanol is set to be 30 ml, NaOH is 5 wt% of methanol solution, sodium borohydride required is 47.7 g, and water required is 45.5 g. Water in this system is recycled from the fuel cell. The fuel cell can make 91.0 g of water and a 50% water recycle rate is assumed. The hydrogen produced is 10.1 g (121.3 L at Standard condition). The system includes a plastic solvent/borohydride storage system, a stainless steel catalytic reactor with 10 g Ru-based catalysts, a filtration unit, and a plastic storage chamber for filter cake. The weight of the system is assumed to be 100 g. The storage density is: 10.1/(47.7+30*.79+0.05*30*0.79+100)= 6.0 wt%.

Examples 10 to 15 summarized in Table 2 are illustrative and not intended to limit the scope of the invention. The example cases illustrate densities in excess of the 4.8% value noted in equation B for theoretical methanolysis of sodium borohydride. The example cases also illustrate that hydrogen storage density will depend in part on the weight of the components and auxiliary equipment required by the system. Where water is supplied from external sources such as the fuel cell recycle (as in cases 11, 13, and 15), densities exceed those of comparable systems supplied from on-board water storage chambers (here, example cases 10, 12, and 14, respectively). The example cases also compare favourably to aqueous systems. For example, see the following two single pass aqueous system examples with 100% conversion rates and no recycle of depleted fuel components. For a 15 wt% NaBH₄ solution in water, the highest achievable theoretical hydrogen storage system density is 3.2 wt%, excluding density effects from addition system components. For a 20 wt% NaBH₄ solution in water, that number is 4.2 wt% where density contributions from addition system components are again excluded.

A typical PEM fuel cell operating at overall stack efficiency of approximately 80% can be combined with the hydrogen generation process to provide an overall system efficiency of approximately 75%. A sample fuel cell system incorporating the hydrogen production system is illustrated at Fig. 3. The schematic describes one sample system design for the fuel cell in a battery-powered, electrically motored vehicle.

In the hydrogen generation system (20), the normal hydrogen generator (21) has a fixed amount of methanol (22) that can be replenished. Hydrogen is generated on demand using a controller that dispenses solid sodium borohydride (23) into the hydrogen generator. Water (24) is injected in amounts suitable for theoretical hydrolysis of sodium borohydride.

The anhydrous sodium borate by-product is readily dissolved in methanol. The vapour product stream (25) comprised of hydrogen gas, water vapour, and methanol vapour is contacted with a recycle water stream (26) to hydrate hydrogen and absorb methanol in the vapour phase. Humidified hydrogen (27) is sent to the anode of the fuel cell stack (28) as the fuel feed. Air (29) is pumped into the cathode of the fuel cell stack at an oxygen: hydrogen ratio suitable for increased hydrogen utilization, for example, 2:1.

The example PEM fuel cell stack consists of single cells connected in series with stainless steel bipolar plates interposed therebetween. Cooling plates in alternate cells remove excess heat. Each cell is made of a Nafion® membrane in a membrane electrode assembly (MEA) with platinum based catalyst. The electrodes are made of graphite paper and the MEA is manufactured by hard compressing the components.

A typical working temperature is 80 °C with overall stack efficiency of 65%. The electricity output from the fuel cell is sent to the electric motor (30) for constant speed driving or battery (31) recharge. Water (32) is supplied to the anode assuming a back osmosis drag of up to 10% from the cathode. Hot water produced in the fuel cell stack (33) can be used to heat up reactants and to strip off methanol vapour, and then be recycled back into the water storage chamber. Surplus water (34) can be stored to cool the fuel cell if required, or can be disposed via an exhaust pipe. Where water produced in the fuel cell is not readily reusable, water can be sourced otherwise.

A cold start-up unit (35) is provided with methanol and 10 wt% cobalt chloride. The cold start-up unit generates hydrogen at cold temperatures by methanolysis of sodium borohydride with the aid of the catalyst. The cold start-up unit releases heat that warms the fuel cell and the normal hydrogen generating unit. When a set point temperature is reached, the start-up unit is shut down and hydrogen production continues via the normal hydrogen generator. Methanol supply for the cold start-up unit can be replenished from storage. Additional catalyst supply is typically not required because the product stream is gaseous and cobalt chloride has minimal vapour pressure at normal environmental conditions .

The above-noted examples and exemplary embodiments are descriptive, and are not intended to limit the scope of invention. Headings are worded according to the PCT requirements. Changes to the claims both as presented and in amended form can be made without departing from the scope and spirit of the invention in its aspects.

INDUSTRIAL APPLICABILITY

The relevant industrial applicability is the area of hydrogen storage and generation, and hydrogen use in fuel cells.

Claims

THE CLAIMS THAT DEFINE THE MATTER FOR WHICH PROTECTION IS SOUGHT ARE:

1. A system comprising, a hydrogen generation reactor, a reactor inlet, a reactor outlet for controlling output, water, at least one chemical hydride of formula M(BH4)_χ/ wherein M is an element selected from a group consisting of groups 1 and 2 of the periodic table, B is an element selected from a group consisting of group 13 of the periodic table, H is hydrogen, and x is a positive integer; at least one alcohol of formula R-OH, wherein R is an alkyl group, and wherein a water: total dissolved hydride ratio is suitable for theoretical hydrolysis of total dissolved hydride, and an alcohol: total dissolved hydride ratio is suitable for pseudo-first order alcoholysis of total dissolved hydride.

2. The system as claimed in claim 1, further comprising a stabilizer for stabilizing the at least one hydride with a member selected from the group consisting of the water and the alcohol.

3. The system as claimed in any one of claims 1 and 2, further comprising at least one catalyst.

4. The system as claimed in claim 3, wherein a catalytic content includes a base metal.

5. The system as claimed in claim 4, wherein the catalytic content includes at least one element selected from the group consisting of copper, iron, nickel, and cobalt.

6. The system as claimed in any one of claims 1 to 5, wherein a precious metal catalytic content is negligible.

7. The system as claimed in any one of claims 2 to 6, wherein a catalyst structure includes at least one member selected from the group consisting of metal mesh, metal foam, beads, and coated substrates.

8. The system as claimed in any one of claims 1 to 7, wherein a total dissolved hydride conversion is in the range from about 100% to about 10%.

9. The system as claimed in any one of claims 1 to 7, wherein a total dissolved hydride conversion is in the range from about 100% to about 1%.

10. The system as claimed in any one of claims 1 to 9, wherein the water is reactive with a compound of formula M( (BO-R)₄)_x according to M( (BO-R)₄)_x + 2_X(H₂O) = M(BO₂)_x + 4x(R-0H) .

11. The system as claimed in any one of claims 1 to 10, wherein the alcohol: total dissolved hydride ratio is from about 5:1 to about 100:1.

12. The system as claimed in any one of claims 1 to 10, wherein the alcohol: total dissolved hydride ratio is from about 7:1 to about 50:1.

13. The system as claimed in any one of claims 1 to 10, wherein the alcohol: total dissolved hydride ratio is about 10:1.

14. The system as claimed in any one of claims 1 to 13, wherein the water: total dissolved hydride ratio is from about 3.0:1 to about 0.05:1.

15. The system as claimed in any one of claims 1 to 13, wherein the water: total dissolved hydride ratio is from about 2.5:1 to about 0.5:1.

16. The system as claimed in any one of claims 1 to 13, wherein the water: total dissolved hydride ratio is from about 2.1 to about 1.5:1.

17. The system as claimed in any one of claims 1 to 13, wherein the water: total dissolved hydride ratio is from about 2.0:1.

18. The system as claimed in any one of claims 1 to 17, wherein the water is at least one member selected from the group consisting of off board supplied water and fuel cell recovered water.

19. The system as claimed in any one of claims 1 to 16, wherein the water is fuel cell recovered water.

20. The system as claimed in any one of claims 1 to 17, wherein the water is supplied together with the alcohol.

21. The system as claimed in any one of claims 1 to 20, wherein the alcohol is at least one member selected from the group consisting of off board supplied alcohol, depleted reactor solution, and depleted reactor solution recovered alcohol.

22. The system as claimed in claim 20, wherein the alcohol is at least one member selected from the group consisting of the depleted reactor solution and the depleted reactor solution recovered alcohol.

23. The system as claimed in any one of claims 21 and 22, wherein the at least one hydride is at least one member selected from the group consisting of off board supplied hydride, the depleted reactor solution, and the depleted reactor solution recovered hydride.

24. The system as claimed in claim 23, wherein the at least one hydride is at least one member selected from the group consisting of depleted reactor solution and depleted reactor solution recovered hydride.

25. The system as claimed in any one of claims 1 to 24, further comprising a storage chamber for supplying the reactor.

26. The system as claimed in claim 25, wherein the storage chamber includes at least one dissolved hydride and the alcohol.

27. The system as claimed in any one of claims 25 and 26, wherein the storage chamber includes at least one solid hydride.

28. The system as claimed in any one of claims 26 and 27, wherein the storage chamber supplies the reactor with the at least one dissolved hydride.

29. The system as claimed in any one of claims 1 to 28, further comprising at least one supplemental storage chamber for supplying the reactor with at least one member selected from the group consisting of the water and the alcohol.

30. The system as claimed in any one of claims 1 to 29, wherein the system is continuous .

31. The system as claimed in claim 30, wherein the continuous system comprises at least two passes.

32. The system as claimed in any one of claims 1 to 31, wherein the reactor is a catalytic reactor.

33. The system as claimed in any one of claims 30 to 32, wherein a single pass total dissolved hydride conversion is from about 100% to about 10%.

34. The system as claimed in any one of claims 30 to 32, wherein the single pass total dissolved hydride conversion is from about 100% to about 1%.

35. The system as claimed in any one of claims 30 to 34 , wherein a process control includes variable conversion rates.

36. The system as claimed in any one of claims 33 to 35, wherein a total storage density is independent from the single pass total dissolved hydride conversion.

37. The system as claimed in any one of claims 1 to 36, wherein the at least one chemical hydride includes sodium borohydride.

38. The system as claimed in any one of claims 1 to 37, wherein the at least one alcohol includes methanol.

39. The system as claimed in claim 3, wherein hydrogen is produced for about 100 hours.

40. The system as claimed in claim 39, wherein depleted solution is recycled to the reactor.

41. The system as claimed in any one of claims 39 and 40, wherein hydrogen production is 3.4 grams .

42. The system as claimed in any one of claims 39 to 41, wherein power production is 1 Watt.

43. The system as claimed in any one of claims 39 to 42, wherein the alcohol is methanol, methanol content is 20 ml, sodium borohydride content is 15.9 grams, water content is 15.2 grams, sodium hydroxide content is 5 percent by weight, catalyst is Ru- Al_.0, pellets, and temperature is about 20 degrees Celsius.

44. The system as claimed in any one of claims 39 to 43, wherein the water is supplied on board and the total system density excluding equipment weight is 7.1 percent by weight.

45. The system as claimed in any one of claims 39 to 43, wherein the water is supplied from a fuel cell and the total system density excluding equipment weight is 10.5 percent by weight.

46. The system as claimed in claim 39, wherein hydrogen production is 10.1 grams.

47. The system as claimed in any one of claims 39 and 46, wherein power production is 3 Watts .

48. The system as claimed in any one of claims 39, 46, and 47, wherein the alcohol is methanol, methanol content is 30 ml, sodium borohydride content is 47.7 grams, water content is 45.5 grams, sodium hydroxide content is 5 percent by weight, the

Celsius .

49. The system as claimed in any one of claims 39 and 46 to 48, wherein the water is supplied on board and the total system density excluding equipment weight is 8.5 percent by weight.

50. The system as claimed in any one of claims 39 and 46 to 48, wherein the water is supplied on board and the total system density including system equipment weight of 100 grams is 4.7 percent by weight.

51. The system as claimed in any one of claims 39 and 46 to 48, wherein the water is supplied from a fuel cell and the total system density including system equipment weight of 100 grams is 6.0 percent by weight.

52. The system as claimed in any one of claims 39, 46, and 47, wherein the alcohol is methanol, methanol content is 20 ml, sodium borohydride content is 47.7 grams , water content is 45.5 grams , sodium hydroxide content is 5 percent by weight, the catalyst is Ru-Al-,0, pellets, and temperature is about 20 degrees

Celsius .

53. The system as claimed in any one of claims 39, 4β, 47, and 52, wherein the water is supplied from a fuel cell and the total system density excluding equipment weight is 14.9 percent by

54. The system as claimed in claim 3, wherein hydrogen is produced for about 50 hours.

55. The system as claimed in any one of claims 3 and 54, wherein depleted solution is recycled to the reactor.

56. The system as claimed in any one of claims 3, 54, and 55, wherein hydrogen production rate is 10 ml/minute.

57. The system as claimed in any one of claims 3, 54, 55, and 56, wherein the alcohol is methanol, methanol content is 200 ml, sodium borohydride content is 13.1 grams, water content is 13.0 grams, sodium hydroxide content is 7.9 grams, catalyst is Ru- Al ,O, and temperature is about 20 degrees Celsius.

58. The system as claimed in claim 3, wherein hydrogen is produced for about 42 hours.

59. The system as claimed in any one of claims 3 and 58, wherein depleted solution is recycled to the reactor.

60. The system as claimed in any one of claims 3, 58, and 59, wherein hydrogen production rate is 11 ml/minute.

61. The system as claimed in any one of claims 3, 58, 59, and 60, wherein the alcohol is methanol, methanol content is 50 ml, sodium borohydride content is 15.0 grains, water content is 14.1 grams, sodium hydroxide content is 7.9 grams, catalyst is Ru- Al-,0-,, and temperature is about 20 degrees Celsius.

62. The system as claimed in claim 3, wherein hydrogen is produced for about 8 hours .

63. The system as claimed in any one of claims 3 and 62, wherein hydrogen production rate is 20 ml/min.

64. The system as claimed in any one of claims 3, 62, and 63, wherein the alcohol is methanol, methanol content is 200 ml, sodium borohydride content is 33.0 grams, water content is 30.3 grams, sodium hydroxide content is 23.6 grams, catalyst is Ru- SiO,, and temperature is about 20 degrees Celsius.

65. The system as claimed in claim 3, wherein hydrogen is produced for about 150 minutes.

66. The system as claimed in any one of claims 3 and 65, wherein hydrogen production rate is 10 ml/min.

67. The system as claimed in any one of claims 3, 65, and 66, wherein the alcohol is methanol, methanol content is 50 ml, sodium borohydride content is 6.4 grams, water content is 6.1 grams, sodium hydroxide content is 2.0 grams, catalyst is Ru- SiO,, and temperature is about 20 degrees Celsius.

68. The system as claimed in claim 3, wherein hydrogen is produced for about 14.5 minutes.

69. The system as claimed in any one of claims 3 and 68, wherein

70. The system as claimed in any one of claims 3, 68, and 69. wherein the alcohol is methanol, methanol content is 30 ml,

34 sodium borohydride content is 0.8 grams, water content is 0.8 grams, sodium hydroxide content is 1.1 grams, catalyst is Ru- Al.O,, and temperature is about 0 degrees Celsius.

71. The system as claimed in claim 3, wherein hydrogen is produced for about 18 hours.

72. The system as claimed in any one of claims 3 and 71, wherein hydrogen production rate is 5 ml/min.

73. The system as claimed in any one of claims 3, 71, and 72, wherein the alcohol is methanol, methanol content is 100 ml, sodium borohydride content is 6.1 grams, water content is 0.006 ml/min, sodium hydroxide content is 4.0 grams, catalyst is Ru- SiO,, temperature is about 20 degrees Celsius.

74. The system as claimed in any one of claims 3, 71, 72, and 73, wherein hydrogen is produced for an additional about 50 hours .

75. The system as claimed in any one of claims 3 and 71 to 74, wherein hydrogen production in the additional about 50 hours is varied from earlier production.

76. The system as claimed in any one of claims 3 and 71 to 75, wherein hydrogen production in the additional 50 hours is 1.5 ml/min.

77. The system as claimed in claim 2, wherein hydrogen is produced for about 400 minutes.

78. The system as claimed in any one of claims 2 and 77, wherein hydrogen production rate is 0.0008 ml/min.

79. The system as claimed in any one of claims 2, 77, and 78, wherein the alcohol is methanol, methanol content is 18 ml, sodium borohydride content is 0.038 grams, water content is 0.036 grams, and temperature is about 0 degrees Celsius.

80. The system as claimed in claim 2, wherein hydrogen is produced for about 12 hours.

81. The system as claimed in any one of claims 2 and 8O_, wherein hydrogen production is 0.003 ml/min.

82. The system as claimed in any one of claims 2, 80, and 81, wherein the alcohol is methanol, methanol content is 18 ml, sodium borohydride content is 0.4 grams, water content is 0.038 grams, and temperature is about minus 20 degrees Celsius.

83. The system as claimed in any one of claims 1 to 82, wherein hydrated borate formation is inhibited.

84. The system as claimed in any one of claims 23 to 38, wherein at least one controller controls a supply for at least one member selected from the group consisting of the off board supplied hydride, the off board supplied alcohol, the off board supplied water, the depleted reactor solution, the depleted reactor solution recovered hydride, the depleted reactor solution recovered alcohol . and the fuel cell recovered water.

85. The system as claimed in any one of claims 1 to 84, further comprising a fuel cell for receiving hydrogen fuel.

86. The system as claimed in claim 85, wherein the fuel cell is a PEM fuel cell stack.

87. The system as claimed in any one of claims 85 and 86, wherein electric output from the fuel cell stack is sent to an electric motor.

88. The system as claimed in any one of claims 85 to 87, wherein the fuel cell generated water is supplied to at least one member of the group consisting of an anode, a reactant heater, an alcohol vapour stripper, a water storage chamber, an exhaust outlet.

89. The system as claimed in any one of claims 1 to 88, further comprising a cold start-up unit for generating hydrogen by catalytic alcoholysis of the at least one hydride.

90. The system as claimed in claim 89, wherein the cold start-up unit releases heat to the system.

91. The system as claimed in any one of claims 89 and 90, wherein the cold start-up unit shuts down when a set point temperature is reached.

92. The system as claimed in any one of claims 1 to 91, wherein the system supplies hydrogen to fuel cell applications in confined environments.

93. The system as claimed in any one of claims 1 to 92, wherein the system supplies hydrogen to fuel cell applications for portable devices.

94. The system as claimed in any one of claims 1 to 93, wherein the system supplies hydrogen to fuel cell applications for automotive devices .

95. The system as claimed in any one of claims 1 to 38 and 83 to 94, wherein a start-up ambient operating temperature is from about minus 50 to about 60 degrees Celsius.