METHOD FOR OBTAINING HYDROGEN

Abstract

The present invention provides a new method for obtaining hydrogen gas that comprises the stages of providing at least one aluminium alloy; providing at least one hydride of general formula (I), where X is selected between B and Al; Y is selected from among Li, Na, K, Mg, Ca and Al; and n is an integer number from 1 to 3; and providing an aqueous medium; so that the reaction between said aluminium alloy with said hydride in said aqueous medium is carried out at a temperature between 4 and 300° C. to produce hydrogen gas and other reaction products with good yields.

Description

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the evolution of hydrogen gas (volume in ml) obtained from 0.210 g of an Al/Si alloy, in which the medium is water at 75° C. (-♦-), water with 0.2 g/l of Ca(OH)₂ at 75° C. (-▴-) and water with 2.0 g/l of Ca(OH)₂ at 75° C. (-▪-). Said figure describes hydrogen being obtained from the state of the art prior to the present invention.

FIG. 2 shows the evolution of hydrogen gas (ml) obtained from a mixture of 0.210 g of an Al/Si alloy and 0.103 g of NaBH₄ (-▪-), in which the medium is water at 75° C., when compared with the addition (-♦-) of hydrogen gas obtained using 0.210 g of an Al/Si alloy and hydrogen gas obtained using 0.103 g of NaBH₄ separately.

FIG. 3 shows the evolution of hydrogen gas (ml) obtained from a mixture of 0.219 g of an Al/Si alloy and 0.107 g of NaBH₄ (-▪-), in which the medium is water with 0.2 g/l of Ca(OH)₂ at 75° C., when compared with the addition (-♦-) of hydrogen gas obtained using 0.219 g of an Al/Si alloy hydrogen gas obtained using 0.107 g of NaBH₄ separately.

FIG. 4 shows the evolution of hydrogen gas (ml) obtained from 0.219 g of an Al/Co alloy and 0.114 g of NaBH₄ (-▪-), in which the medium is water with 2.0 g/l of Ca(OH)₂ at 75° C., when compared with the addition (-♦-) of hydrogen gas obtained using 0.219 g of an Al/Co alloy and hydrogen gas obtained using 0.114 g of NaBH₄ separately.

FIG. 5 shows the evolution of hydrogen gas (ml) obtained from a mixture of 0.215 g of an Al/Mg alloy and 0.102 g of NaBH₄ (-▪-), in which the medium is water with 2.0 g/l of Ca(OH)₂ at 75° C., when compared with the addition (-♦-) of hydrogen gas obtained using 0.215 g of an Al/Mg alloy and hydrogen gas obtained using 0.102 g of NaBH₄.

FIG. 6 shows the evolution of hydrogen gas (ml) obtained from a mixture of 0.210 g of an Al/Si alloy and 0.109 g of NaBH₄ (-▪-), in which the medium is water with 2.0 g/l of Ca(OH)₂ at 75° C., when compared with the addition (-♦-) of hydrogen gas obtained using 0.210 g of an Al/Si alloy and hydrogen gas obtained using 0.109 g of NaBH₄, and both evolutions of hydrogen gas separately: Al/Si (-χ-) and NaBH₄ (-▴-).

Claims

1. A method for obtaining hydrogen gas, comprising the following steps: i) providing at least one aluminium alloy;ii) providing at least one hydride of general formula (I): Y[XH4]n where X is selected between B and Al; Y is selected from among Li, Na, K, Mg, Ca and Al; and n is an integer number from 1 to 3; andiii) providing an aqueous medium;so that the reaction between said aluminium alloy with said hydride in said aqueous medium is carried out at a temperature between 4 and 300° C. to produce hydrogen gas and other reaction products.

2. Method according to claim 1, wherein said aluminium alloy is selected from among Al/Si, Al/Co and Al/Mg.

3. Method according to claim 1, wherein said aqueous medium is water.

4. Method according to claim 1, wherein said aqueous medium is prepared by dissolving a base in water.

5. Method according to claim 4, wherein said base is selected from Ca(OH)2, NaOH, KOH and mixtures thereof.

6. Method according to claim 5, wherein the Ca(OH)2 is in any concentration up to saturation.

7. Method according to claim 5, wherein the NaOH is in a concentration of up to 5M.

8. Method according to claim 5, wherein the KOH is in a concentration of up to 5M.

9. Method according to claim 1, wherein the temperature is between 50 and 100° C.

10. Method according to claim 1, wherein the percentage of aluminium in relation to the compounds provided in stages i) and ii) is between 10% and 95% by weight.

11. Method according to claim 10, wherein the percentage of aluminium is between 20 and 70% by weight.

12. Method according to claim 1, wherein the compounds provided in stages i) and ii) are in the form of powder, flakes, pellets, monoliths, granules or foils.

13. Method according to claim 12, wherein the compounds provided in stage i) are in powder form.

14. Method according to claim 12, wherein the compounds provided in stage ii) are in powder form.