Method of catalytically pyrolyzing a methane-containing stream
AssigneeShell USA, Inc.
InventorsZhe CUI, Leonardo SPANU
Life of this patent
Estimating the term…
Abstract
A method of catalytically pyrolyzing a gaseous methane-containing stream, includes feeding the stream in the form of gas bubbles into a reaction zone containing catalyst particles suspended in a molten salt and subjecting the stream to catalytic pyrolysis thereby obtaining solid carbon and gaseous hydrogen. As the molten salt, solid carbon and gaseous hydrogen are allowed to move upwards from the reaction zone to an intermediate zone, gas bubbles are broken by first bubble breakers having an open area of greater than 90%. As solid carbon, gaseous hydrogen and part of the molten salt are allowed to move further upwards from the intermediate zone to a separation zone, gas bubbles are broken by second bubble breakers.
Claims14
A method of catalytically pyrolyzing a methane-containing stream, the method at least comprising the steps of:
- (a) providing a gaseous methane-containing stream (10);
- (b) feeding the gaseous methane-containing stream provided in step (a) in the form of gas bubbles into a reaction zone (3) containing molten salt and catalyst particles, wherein the catalyst particles are suspended in the molten salt;
- (c) subjecting the methane-containing stream to catalytic pyrolysis in the reaction zone (3) thereby obtaining solid carbon and gaseous hydrogen;
- (d) allowing the molten salt, solid carbon and gaseous hydrogen to move upwards from the reaction zone (3) to an intermediate zone (4) whilst catalyst particles are kept in the reaction zone (3);
- (e) optionally, allowing a first part of the molten salt to flow from the intermediate zone (4) to the reaction zone (3), or from an upper part of the reaction zone (3) to a lower part of the reaction zone (3), via a return loop (6);
- (f) allowing solid carbon, gaseous hydrogen and a second part of the molten salt to move further upwards from the intermediate zone (4) to a separation zone (5);
- (g) removing solid carbon and gaseous hydrogen from the separation zone (5) by gas entrainment using an inverted funnel (9);
- wherein gas bubbles are broken by first bubble breakers (7) having an open area of greater than 90% when the molten salt, solid carbon and gaseous hydrogen are moving upwards in step (d) from the reaction zone (3) to the intermediate zone (4);
- and
- wherein gas bubbles are broken by second bubble breakers (8) when the molten salt, solid carbon and gaseous hydrogen are moving upwards in step (f) from the intermediate zone (4) to the separation zone (5).
An apparatus (1) for catalytically pyrolyzing a methane-containing stream, the apparatus at least comprising:
- a reaction zone (3) containing molten salt and catalyst particles, wherein during use a methane-containing stream (10) can be fed into the reaction zone (3) in the form of gas bubbles and the catalyst particles can be suspended in the molten salt, and wherein during use the methane-containing stream can be subjected to catalytic pyrolysis in the reaction zone (3) thereby obtaining solid carbon and gaseous hydrogen;
- an intermediate zone (4) for receiving molten salt, solid carbon and gaseous hydrogen that during use have moved upwards from the reaction zone (3) to the intermediate zone (4) whilst catalyst particles are kept in the reaction zone (3);
- optionally, a return loop (6) for allowing a first part of the molten salt to flow from the intermediate zone (4) to the reaction zone (3), or from an upper part of the reaction zone (3) to a lower part of the reaction zone (3);
- a separation zone (5) for receiving solid carbon, gaseous hydrogen and a second part of the molten salt that have moved further upwards from the intermediate zone (4) to the separation zone (5), and for separating the solid carbon and gaseous hydrogen from the molten salt;
- first bubble breakers (7) placed between the reaction zone (3) and the intermediate zone (4) that can break gas bubbles when the molten salt, solid carbon and gaseous hydrogen are moving upwards from the reaction zone (3) to the intermediate zone (4), the first bubble breakers (7) having an open area of greater than 90%;
- second bubble breakers (8) placed between the intermediate zone (4) and the separation zone (5) that can break gas bubbles when the molten salt, solid carbon and gaseous hydrogen are moving upwards from the intermediate zone (4) to the separation zone (5);
- a sucker (9) for removing solid carbon and gaseous hydrogen from the separation zone (5) by gas entrainment, using an inverted funnel.
The apparatus according to claim wherein during use the first bubble breakers (7) are fully submerged in molten salt.
Dependencies are inferred from the claim text.