Process and device for direct thermal decomposition of hydrocarbons with liquid metal in the absence of oxygen for the production of hydrogen and carbon

Patent metadata

Field	Value
Publication number	US-11746010-B2
Application number	US-201916967694-A
Country	US
Kind code	B2
Filing date	Feb 1, 2019
Priority date	Feb 6, 2018
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

Direct thermal decomposition of hydrocarbons into solid carbon and hydrogen is performed by a process and a device. The process comprises preheating a hydrocarbon gas stream to a temperature between 500° C. and 700° C. and injecting the pre-heated hydrocarbon gas stream into the reactor pool of a liquid metal reactor containing a liquid media; forming a multi-phase flow with a hydrocarbon gas comprising hydrogen and solid carbon at a temperature between 900° C. and 1200° C.; forming a carbon layer on the free surface of the liquid media made up of solid carbon particles which are then displaced into at least one carbon extraction system and at least one recipient for collecting them; and, at the same time, the gas comprising hydrogen leaves the reactor pool through a porous rigid section, being collected at a gas outlet collector from where the gas comprising hydrogen finally leaves the liquid metal reactor.

First claim

The invention claimed is:

1. A process for the direct thermal decomposition of hydrocarbons into solid carbon and hydrogen comprising:
a. preheating a hydrocarbon gas stream and conducting the hydrocarbon gas stream from at least one hydrocarbon gas stream inlet, located at a top part of a liquid metal reactor, to a bottom part of the liquid metal reactor, through a pre-heating conduit located surrounding the external perimeter of the liquid metal reactor, said pre-heating conduit being located inside a thermal insulation means, and obtaining a pre-heated hydrocarbon gas stream at a temperature between 500° C. and 700° C.;
b. injecting the pre-heated hydrocarbon gas stream obtained in step (a) into a reactor pool, containing a liquid metal media, of the liquid metal reactor, wherein said injection takes place at the bottom part of the liquid metal reactor through a porous section or a set of gas injection orifices;
c. the hydrocarbon gas injected into the liquid metal reactor in step (b) moves upwards by buoyancy forming a multi-phase flow including a hydrocarbon gas comprising hydrogen and solid carbon, at the same time that the liquid metal media inside the reactor pool is maintained at a temperature comprised between 900° C. and 1200° C.;
d. the solid carbon obtained in step (c) is accumulated at a top part of the reactor pool, on a free surface of the liquid metal media located inside the liquid metal reactor, forming a carbon layer made up of solid carbon particles;
e. once the carbon layer reaches a determined thickness, the carbon particles constituting the carbon layer are displaced into at least one carbon extraction system consisting of a porous rigid section located at the top of the liquid metal reactor, above the free surface of the liquid metal media, from which the carbon particles are conducted into at least one recipient for collecting the carbon particles; and
f. at the same time, the gas comprising hydrogen obtained in step (c) leaves the reactor pool through the porous rigid section, being collected at a gas outlet collector from where the gas comprising hydrogen finally leaves the liquid metal reactor.

2. A process according to claim 1 , wherein the temperature inside the reactor pool is reached by means of at least one thermal heater located inside the reactor pool.

3. A process according to claim 1 , wherein the thickness of the carbon layer reached in step (c) is between 1 cm and 15 cm.

4. A process according to claim 1 , wherein the conduction of the carbon particles towards the recipient for collecting said carbon particles is facilitated by a vibrational movement generated by a mechanical shaft.

5. A device for the direct thermal decomposition of hydrocarbons into solid carbon and hydrogen, comprising:
a. a pre-heating conduit comprising at least one hydrocarbon gas inlet located at a top part of a liquid metal reactor and at least one hydrocarbon gas outlet located at a bottom part of the liquid metal reactor corresponding to the hydrocarbon gas inlet into the liquid metal reactor, and a reactor pool designed for containing a liquid metal media, wherein said pre-heating conduit is located inside a thermal insulation means;
b. the liquid metal reactor further comprises at least one thermal heater located inside the reactor pool for inducing a homogeneous temperature inside the liquid metal reactor;
c. at the top of the liquid metal reactor, at least one carbon extraction system consisting of a porous rigid section is located, said porous rigid section being connected to at least one recipient suitable for collecting carbon particles; and
d. the porous rigid section incorporates, at the top of it, a carbon barrier designed for the carbon particle retention, wherein said carbon barrier separates the porous rigid section from a gas outlet collector.

6. The device, according to claim 5 , wherein the connection between the porous rigid section and the recipient suitable for collecting carbon particles further incorporates mechanical means for facilitating the movement of the solid carbon particles.

Assignees

• Univ Madrid Politecnica
• Karlsruher Inst Technologie

Inventors

• Abánades Velasco Alberto
• Muñoz Antón Javier
• Martínez-Val Peñalosa José María
• Geissler Tobias
• Stoppel Leonid
• Dietrich Benjamin
• Plevan Michael
• Wetzel Thomas

Classifications

• C01B3/34 Primary

  by reaction of hydrocarbons with gasifying agents · CPC title

• C01B3/348 Primary

  Chemistry & Metallurgy · mapped topic

• B01J6/00

  Heat treatments such as} Calcining; Fusing {; Pyrolysis (furnaces F27D) · CPC title

• C01B32/05

  Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30 · CPC title

• C01B2203/0272

  containing a non-catalytic decomposition step · CPC title