Methods and devices for storage and release of hydrogen

Patent metadata

Field	Value
Publication number	US-10944119-B2
Application number	US-201615573634-A
Country	US
Kind code	B2
Filing date	May 13, 2016
Priority date	May 13, 2015
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

The invention relates to a process for generating hydrogen, comprising decomposing in a reaction vessel aqueous alkali formate in the presence of a transition metal-containing catalyst system dissolved in one or more organic solvent(s), characterized in that said organic solvent(s) comprise at least one solvent which is water-immiscible, thereby releasing hydrogen and forming bicarbonate in the aqueous phase, and separating the catalyst-containing organic solvent(s) from said bicarbonate. Also disclosed are apparatuses for carrying out hydrogen generation.

First claim

The invention claimed is:

1. A process for generating hydrogen, comprising decomposing in a reaction vessel aqueous alkali formate in the presence of a transition metal-containing catalyst system dissolved in one or more organic solvent(s), characterized in that said organic solvent(s) comprise at least one solvent which is water-immiscible, thereby releasing hydrogen and forming bicarbonate in the aqueous phase, and separating the catalyst-containing organic solvent(s) from said bicarbonate.

2. A process according to claim 1 , wherein the alkali formate is KHCO 2 .

3. A process according to claim 1 , wherein the water-immiscible organic solvent is selected from the group consisting of aliphatic and cyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, esters, ketones, ethers, alkanols having not less than 6 carbon atoms and carbonate solvents.

4. A process according to claim 1 , wherein the catalyst system is dissolved in a mixture of solvents comprising a first organic solvent, which is the water-immiscible solvent, and a second solvent, which is a polar solvent.

5. A process according to claim 4 , wherein the second solvent is polar protic organic solvent.

6. A process according to claim 5 , wherein the polar protic solvent is selected from the group consisting of C2-C6 alkanols.

7. A process according to claim 6 , wherein the catalyst system is dissolved in a mixture of solvents comprising at least a first solvent and a second solvent, characterized in that the first solvent is an aliphatic or cyclic hydrocarbon selected from the group consisting of C6-C10 alkanes, C6-C10 alkenes, cycloalkanes and cycloalkenes, and the second solvent is selected from the group consisting of C2-C5 alkanols.

8. A process according to claim 6 , wherein the catalyst system is dissolved in a mixture of solvents comprising at least a first solvent and a second solvent, characterized in that the first solvent is an aromatic hydrocarbon selected from the group consisting of alkyl-substituted benzenes, and the second solvent is selected from the group consisting of C2-C5 alkanols.

9. A process according to claim 6 , wherein the catalyst system is dissolved in a mixture of solvents comprising at least a first solvent and a second solvent, characterized in that the first solvent is a halogenated hydrocarbon selected from the group consisting of halogenated C1-C3 alkanes, C2-C3 alkenes, halogen-substituted cyclic hydrocarbons and halogen-substituted aromatic hydrocarbons, and the second solvent is selected from the group consisting of C2-C5 alkanols.

10. A process according to claim 6 , wherein the catalyst system is dissolved in a mixture of solvents comprising at least a first solvent and a second solvent, characterized in that the first solvent is selected from the group consisting of water-immiscible esters, water-immiscible ethers, water-immiscible ketones and water-immiscible alkanols having not less than 6 carbon atoms, and the second solvent is selected from the group consisting of C2-C5 alkanols.

11. A process according to claim 6 , wherein the catalyst system is dissolved in a mixture of solvents comprising at least a first solvent and a second solvent, characterized in that the first solvent is a carbonate liquid selected from the group consisting of (R 1 ) n —X—C(O)—X—(R 2 ) n , where X indicates oxygen, R 1 and R 2 , which may be the same or different, are C1-C3 alkyl groups and n is 1, and the second solvent is selected from the group consisting of C2-C5 alkanols.

12. A process according to claim 6 , wherein the alkanol is selected from the group consisting of ethanol, n-butanol, n-pentanol and mixtures thereof.

13. A process according to claim 1 , wherein the transition metal is a platinum-group metal.

14. A process according to claim 13 , wherein the platinum-group metal is ruthenium.

15. A process according to claim 13 , wherein the catalyst system comprises:
a catalyst precursor which is a platinum-group metal complex or a platinum-group metal salt;
and an additive phosphorous ligand.

16. A process according to claim 15 , wherein the catalyst precursor is selected from the group consisting of [RuX 2 (arene)] 2 , wherein arene indicates an aromatic hydrocarbon selected from the group consisting of benzene and alkyl-substituted benzene, and X is halide.

17. A process according to claim 16 , wherein the [RuX 2 (arene)] 2 is [RuX 2 (cymene)] 2 .

18. A process according to claim 15 , wherein the additive phosphorous ligand is selected from the group consisting of: 1,1-bis(diphenylphosphino)methane; 1,3 bis(diphenylphosphinomethyl)benzene; triphenylphosphine (P(Ph) 3 ) and tetraphos (PP3).

19. A process according to claim 15 , wherein the catalyst system is activated in-situ.

20. A process according to claim 15 , wherein the catalyst system is activated ex-situ, by combining in an organic solution the catalyst precursor and the additive phosphorous ligand in the presence of a reducing agent to form a catalytically active form, and supplying said organic solution to the reaction vessel to decompose formate.

21. A process according to claim 1 , wherein a surfactant is present in the reaction vessel.

22. A process for generating hydrogen according to claim 1 , comprising continuously feeding to the reaction vessel an aqueous MHCO 2 stream and an organic stream in which the metal-containing catalyst system is dissolved in the organic solvent(s), dehydrogenating said MHCO 2 in said reaction vessel, thereby releasing hydrogen and forming bicarbonate (MHCO 3 ) slurry, continuously discharging from said reaction vessel a reaction mixture consisting of solid bicarbonate and a liquid component, continuously separating the reaction mixture into solid and one or more liquid components, collecting said solid bicarbonate and recycling one or more liquid component(s) to said reaction vessel.

Assignees

• Yissum Res Dev Co Of Hebrew Univ Jerusalem Ltd
• Energystoredge Ltd

Inventors

• Sasson Yoel
• Toubiana Judith
• Givant Ariel
• Rothschild Sorel

Classifications

• Y02E60/32

  Hydrogen storage · CPC title

• H01M8/0618 Primary

  Reforming processes, e.g. autothermal, partial oxidation or steam reforming · CPC title

• H01M8/0612

  from carbon-containing material · CPC title

• H01M8/04201

  Reactant storage and supply, e.g. means for feeding, pipes · CPC title

• H01M8/04089

  of gaseous reactants · CPC title