Process for production of hydrogen

Patent metadata

Field	Value
Publication number	US-9968913-B2
Application number	US-201414655487-A
Country	US
Kind code	B2
Filing date	Jan 9, 2014
Priority date	Jan 10, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present invention relates to a process for production of hydrogen at low temperature starting from alcohols without formation of carbon using an oxyhydride material based on cerium and nickel and to the use of such a material as catalyst for transformation of alcohols to hydrogen.

First claim

The invention claimed is:

1. Process for production of hydrogen at low temperature by transformation of an alcohol or of a mixture of alcohols, said process comprising the steps of:
1) a first step of synthesis of an electrically neutral oxyhydride material M1, based on cerium, nickel, oxygen atoms, hydrogen atoms and optionally a metal M selected from Al and Zr, and in said material:
i) the Ni/Ce molar ratio varies from 0.1 to 5,
ii) the M/Ce molar ratio varies from 0 to 1, and
iii) at least a proportion of the hydrogen atoms present in said material M1 is in the form of hydride ions, said synthesis being carried out according to the following substeps 1-i) to 1-v):
1-i) a first substep of preparation of an aqueous solution comprising at least one cerium precursor, at least one nickel precursor and optionally at least one precursor of metal M,
1-ii) a second substep of coprecipitation of said precursors of cerium, of nickel and optionally of metal M in the form of the corresponding hydroxides of cerium, of nickel and optionally of metal M, by adding at least one precipitant to said aqueous solution,
1-iii) a third substep of filtration of said hydroxides to obtain a filtered solid,
1-iv) a fourth substep of drying the filtered solid obtained above in substep 1-iii) at a temperature between 40° C. and 150° C., for a time between 1 and 24 hours, to obtain an electrically neutral solid material M2 based on cerium, nickel, oxygen atoms, hydrogen atoms and optionally a metal M, in which:
i) the definitions of metal M and the Ni/Ce and M/Ce molar ratios are the same as those relating to the oxyhydride material M1,
ii) at least a proportion of the hydrogen atoms present in said material M2 forms hydroxyl functions with the oxygen atoms, and
iii) said solid material M2 is free from hydride ions, and
1-v) a fifth substep of treatment of the solid material M2 obtained above in the preceding step in the presence of hydrogen, to obtain an oxyhydride material M1,
2) a second step of contacting, at low temperature, the oxyhydride material M1 obtained above in the preceding step, firstly with a gas mixture comprising at least one lower alcohol, water and nitrogen, then secondly with oxygen, wherein the step of synthesis of the oxyhydride material M1 does not comprise a substep of calcination.

2. Process according to claim 1 , wherein the cerium precursor is a cerium(III) salt selected from cerium nitrate, cerium acetate and cerium chloride and in that the nickel precursor is a nickel(II) salt selected from nickel nitrate, nickel chloride and nickel sulphate.

3. Process according to claim 1 , wherein the concentration of cerium precursor and of nickel precursor in said aqueous solution varies independently from 0.1 to 1 mol/l.

4. Process according to claim 1 , wherein the precipitant is selected from triethylamine, ammonium hydroxide, potassium hydroxide, sodium hydroxide and sodium carbonate.

5. Process according to claim 1 , wherein the low temperature is a temperature in the range from 20° C. to 60° C.

6. Process according to claim 1 , wherein the substep 1-v) of treatment of the solid material M2 in the presence of hydrogen is carried out at a temperature from 50° C. to 400° C.

7. Process according to claim 1 , wherein the oxyhydride material M1 is selected from those in which the M/Ce molar ratio is equal to zero and the Ni/Ce molar ratio varies from 0.3 to 1.

8. Process according to claim 1 , wherein said alcohol is selected from methanol, ethanol, propan-1-ol, butan-1-ol and pentan-1-ol and bio-ethanol.

9. Process according to claim 1 , wherein said contacting step 2) is carried out according to the following sequences:
2-i) introducing a water/alcohol/nitrogen gas mixture into a reactor comprising oxyhydride material M1 obtained in the preceding step 1), at a temperature of at least 130° C.,
2-ii) introducing oxygen into the reactor and maintaining the temperature for an induction period of at least 3 minutes, then
2-iii) lowering the temperature to a temperature below 60° C.

10. Process according to claim 9 , wherein said water/alcohol/nitrogen gas mixture is fed into the reactor at a temperature of 160° C. during sequence 2-i) and in that the temperature is lowered to a temperature of 50° C. during step 2-iii).

11. Process according to claim 9 wherein said water/alcohol/nitrogen gas mixture fed into the reactor at the start contains 15 mol % of alcohol relative to the water/alcohol/nitrogen gas mixture.

12. Process according to claim 1 , wherein the water/alcohol molar ratio in the gas mixture varies from 1/2 to 13/1.

13. Process according to claim 1 , wherein the flow rate of the water/alcohol/nitrogen/oxygen gas mixture varies from 10 to 100 ml/min.

14. Process according to claim 1 , wherein the Oz/alcohol molar ratio varies from 0.5/1 to 2.5/1.

15. Process according to claim 1 , wherein an alcohol/water/O 2 /N 2 gas mixture is used in which the molar proportions of the alcohol/water/O 2 /N 2 mixture are 1/3/1.6/1.3.

Assignees

• Centre Nat Rech Scient
• Univ Des Sciences Et Technologies De Lille—Lille 1
• Univ Lille 1

Inventors

• Duhamel Louise
• Fang Wenhao
• Paul Sebastien
• Dumeignil Franck

Classifications

• B01J37/14

  with gases containing free oxygen · CPC title

• C01B2203/1229

  Ethanol · CPC title

• C01B2203/1058

  Nickel catalysts · CPC title

• C01B3/326

  characterised by the catalysts · CPC title

• B01J37/18

  with gases containing free hydrogen · CPC title