Process for the production of hydrogen with total recovery of CO2 and recycling of unconverted methane

Patent metadata

Field	Value
Publication number	US-9896333-B2
Application number	US-201615160787-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	Nov 20, 2008
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

This invention relates to a process for the production of hydrogen from a hydrocarbon feedstock and steam comprising:
A stage for the production of a synthesis gas in a unit for the steam-reforming of the hydrocarbon feedstock, A stage for shift conversion with steam of the synthesis gas that is obtained in the preceding stage producing a hydrogen stream that contains methane and carbon dioxide, A stage for recovering carbon dioxide and methane, present in the stream that is obtained in the shift conversion stage, in the form of hydrates that produce a stream of pure hydrogen, A stage for regeneration of methane, A stage for recycling methane to steam reforming.

First claim

The invention claimed is:

1. A process for the production of hydrogen from natural gas and water vapor comprising:
producing a synthesis gas in a vapor-reforming unit of the hydrocarbon feedstock in the presence of water vapor, whereby a fuel provides heat necessary for reaction,
shift conversion of the synthesis gas that is obtained to produce a stream containing additional hydrogen, additional carbon dioxide and residual methane,
at 0-60° C. and a pressure of 0.2-6 MPa recovering carbon dioxide and methane, present in the stream that is obtained in the shift conversion, in the form of hydrates in the presence of a non-water miscible solvent and at least one amphiphilic compound, and separating a stream enriched in hydrogen,
simultaneously regenerating methane and carbon dioxide at 0-40° C. and a pressure of 0.2-6 MPa,
recycling a methane stream obtained by regeneration to input of vapor reforming,
the amphiphilic compound being
a compound of the formula Rf(CH 2 )(OC 2 H 4 ) n OH, in which Rf is a partially hydrogenated perfluorocarbonated or fluorocarbonated chain in which n is an integer at least equal to 1.

2. The process for the production of hydrogen according to claim 1 , comprising producing electricity from the stream enriched in hydrogen obtained in the recovery of carbon dioxide and methane.

3. The process for the production of hydrogen according to claim 2 , in which the production of electricity is carried out by sending the stream enriched in hydrogen into a combustion chamber.

4. The process for the production of hydrogen according to claim 3 , in which hot flue gasses that are obtained at the end of combustion in the combustion chamber are recycled to the vapor-reforming unit.

5. A process according to claim 1 , wherein the non-water miscible solvent is a hydrocarbon, a silicone, or a halogenated or perhalogenated solvent.

6. A process according to claim 5 , wherein the non-water miscible solvent is an isoparaffinic fraction, a naphthenic fraction, an aromatic fraction, an alkyl aromatic compound, an alkane, cycloalkane or alkylcycloalkane having a flash point higher than 40° C. and a crystallization point less than −5° C.

7. A process according to claim 5 , wherein the silicone is a linear polymethyldisiloxane of the formula (CH 3 ) 3 —SiO—[(CH 3 ) 2 —SiO] n —Si(CH 3 ) 3 , in which n is 1-900, having a viscosity at ambient temperature of 0.1-10,000 mPa·s, a polyethylsiloxane having a viscosity at ambient temperature of 0.1-10,000 mPa·s, a D 4-10 -cyclic polydimethylsiloxane, in which D represents the dimethylsiloxane monomer unit, or polytrifluoropropyl methyl siloxane.

8. A process according to claim 5 , wherein the halogenated or perhalogenated solvent is a perfluorocarbon, a hydrofluoroether or a perfluoropolyether, having a boiling point ≧70° C. at atmospheric pressure and a viscosity less than 1 Pa·s at ambient temperature and atmospheric pressure.

Assignees

• Ifp Energies Now

Inventors

• Bouillon Pierre Antoine
• Huyghe Raphael
• Lugo Rafael
• Giroudiere Fabrice

Classifications

• Y02P30/30

  Cross-Sectional Technologies · mapped topic

• C01B2203/0283

  containing a CO-shift step, i.e. a water gas shift step · CPC title

• B01D53/1493

  Selection of liquid materials for use as absorbents · CPC title

• Y02P20/128

  Cross-Sectional Technologies · mapped topic

• C01B2203/0811

  by combustion of fuel · CPC title