Reactors including self-cleaning rotating elements, and associated systems, devices, and methods

A pyrolysis system comprising:

• a pyrolysis reactor comprising a pyrolysis chamber configured to generate a product stream from a system feed, wherein the system feed comprises a hydrocarbon reactant, and wherein the product stream comprises hydrogen gas and solid carbon;
• a regeneration oxidizer feed, wherein the pyrolysis reactor is configured to react a regeneration oxidizer with carbon buildup in the pyrolysis chamber to generate a regeneration product stream that is output from the pyrolysis reactor, and wherein the regeneration oxidizer feed is configured to remove a first portion of the carbon buildup through oxidation;
• and
• a mechanical removal mechanism, wherein the mechanical removal mechanism is configured to remove a second portion of the carbon buildup.

A pyrolysis reactor configured to generate a product stream from a system feed, wherein the system feed comprises a hydrocarbon reactant, and wherein the product stream comprises hydrogen gas and solid carbon, the reactor comprising:

• a first rotating tube comprising an outer surface;
• a second rotating tube comprising an inner surface, wherein the first rotating tube and the second rotating tube are coaxial and non-concentric;
• and
• a pyrolysis chamber between the outer surface of the first rotating tube and the inner surface of the second rotating tube, wherein pyrolysis of the system feed is configured to occur in the pyrolysis chamber, wherein, in operation:
• the first rotating tube is positioned to receive the solid carbon that deposits on the outer surface and the second rotating tube is positioned to receive the solid carbon that deposits on the inner surface, resulting in carbon buildup on the outer surface and the inner surface, and
• rotation of the first rotating tube and the second rotating tube is configured to remove at least a portion of the carbon buildup.

A method for removing carbon buildup from a pyrolysis system, the method comprising:

• providing the pyrolysis system, the pyrolysis system comprising:
• a pyrolysis reactor comprising a pyrolysis chamber configured to generate a product stream from a system feed, wherein the system feed comprises a hydrocarbon reactant, and wherein the product stream comprises hydrogen gas and solid carbon, wherein at least a portion of the solid carbon builds up in the pyrolysis reactor, resulting in carbon buildup,
• a regeneration oxidizer feed, wherein the regeneration oxidizer feed is configured to react with the carbon buildup, and
• a mechanical removal mechanism;
• controlling a flow of the system feed through the pyrolysis reactor;
• controlling a flow of the regeneration oxidizer feed through the pyrolysis reactor;
• and
• controlling movement of the mechanical removal mechanism, wherein the movement of the mechanical removal mechanism removes at least a portion of the carbon buildup.