Heat source for pyrolysis process

Abstract

Systems and methods are provided for using a reverse flow reactor (or another reactor with flows in opposing directions at different parts of a process cycle) for pyrolysis of hydrocarbons. The systems and methods can include a reactor that includes a combustion catalyst to initiate and/or maintain combustion within the reactor in a controlled manner during the heating and/or regeneration portion(s) of the reaction cycle. A fuel can also be used that has a greater resistance to auto-combustion, such as a fuel that is composed primarily of methane and/or other hydrocarbons. During operation, the temperature in at least an initial portion of the reactor can be maintained at a temperature so that auto-ignition of the auto-combustion resistant fuel injected during the heating step(s) is reduced or minimized. This can allow combustion to be initiated when the auto-combustion resistant fuel comes into contact with the catalyst. Additionally, the amount and positioning of the catalyst within the reactor can be controlled so that combustion of the fuel takes place over a substantially longer period of time than combustion during a conventional reactor heating step. Because the fuel is moving within the reactor during combustion, extending the combustion time results in a substantial expansion of the volume where combustion occurs. Optionally in combination with an improved reaction cycle, this can expand the portion of the reactor that is directly heated by combustion, allowing for an improved temperature distribution within the reactor during the pyrolysis step.