Method and system for direct thermal decomposition of a hydrocarbon compound into carbon and hydrogen

A method of carrying out direct thermal decomposition of a hydrocarbon compound into carbon and hydrogen, comprising:

• introducing a gaseous feed stream comprising at least one hydrocarbon compound into a reactor;
• and
• removing at least hydrogen gas and particulate carbon formed by thermal decomposition from the reactor,
• wherein the method includes:
• providing in the reactor a layer permeable to the particulate carbon and comprising loose particles other than the particulate carbon in a gas phase, and
• passing the gaseous feed stream through the layer,
• wherein the loose particles other than the particulate carbon comprise particles comprising a catalyst on a carrier;
• and
• wherein the method includes:
• (i) removing at least part of the layer from the reactor, (ii) separating constituents of the removed part, the constituents including some of the particles comprising a catalyst on a carrier, and (iii) returning the separated particles comprising a catalyst on a carrier to the layer;
• wherein:
• the layer forms a fluidised bed;
• and
• the particles comprising a catalyst on a carrier comprise particles of which at least an outer shell is porous and acts as the carrier and which have a hollow core or a porosity decreasing from core to surface.

A system for direct thermal decomposition of a hydrocarbon compound into carbon and hydrogen, comprising:

• a reactor having at least one outlet for a product stream comprising the hydrogen gas;
• a conduit for supplying a gaseous feed stream comprising at least one hydrocarbon compound;
• a device, in communication with the conduit, for introducing the gaseous feed stream into the reactor;
• and
• a quantity of loose particles comprising particles comprising a catalyst on a carrier;
• wherein:
• the reactor includes an inlet for introducing the loose particles into the reactor to form a layer of the loose particles in a gas phase, the layer being permeable to the particulate carbon;
• at least part of the layer is removable from the reactor;
• and
• the system includes:
• (i) at least one device for separating constituents of the removed part, and (ii) a device for returning at least some of the particles comprising a catalyst on a carrier that are comprised amongst the constituents to the layer;
• wherein:
• the reactor comprises a fluidised bed reactor for providing the layer as a fluidised bed, and
• the particles comprising a catalyst on a carrier comprise particles of which at least an outer shell is porous and acts as the carrier and which have a hollow core or a porosity decreasing from core to surface.