Pyrolysis and combustion control in pyrolysis reactors, and associated systems and methods

A pyrolysis system, comprising:

• a combustion component;
• a reaction chamber couplable to a supply of pyrolysis feedstock, wherein the reaction chamber is thermally coupled to the combustion component such that the reaction chamber transfers heat from the combustion component to the pyrolysis feedstock to generate a product stream that includes hydrogen gas and solid carbon;
• and
• a recycling component fluidly coupled to an output of the reaction chamber such that the recycling component directs a portion of the hydrogen gas from the product stream into an input channel fluidly coupled to the combustion component, wherein the recycling component comprises:
• a carbon separator;
• a byproduct separator downstream from the carbon separator, wherein the byproduct separator is configured to send a partially purified gas product to the reaction chamber and/or the combustion component;
• and
• a gas separator downstream from the byproduct separator, wherein the gas separator includes a first output fluidly couplable to a hydrogen output channel and a second output fluidly coupled to the combustion component via the input channel.