High-temperature shock heating for thermochemical reactions

A method, comprising:

• (a) for a first time period, providing one or more reactants in thermal contact with a first heating element in a reactor;
• (b) during a first part of a heating cycle, providing the one or more reactants with a first temperature by heating with the first heating element, such that one or more thermochemical reactions is initiated;
• and
• (c) during a second part of the heating cycle, providing the one or more reactants with a second temperature less than the first temperature,
• wherein a duration of the first time period is equal to or greater than a combined duration of the first and second parts of the heating cycle,
• the combined duration of the first and second parts of the heating cycle is less than five seconds,
• the first heating element operates by Joule heating and has a porous construction that allows gas to flow therethrough,
• the one or more thermochemical reactions comprises pyrolysis, thermolysis, synthesis, hydrogenation, dehydrogenation, hydrogenolysis, or any combination thereof,
• (b) and (c) comprise applying an electrical power waveform to the first heating element, the waveform comprising at least a first electrical power level corresponding to the first temperature and a second electrical power level corresponding to the second temperature;
• and
• the waveform comprises a pulse, a rectangular wave profile, a stepped profile, a triangular wave profile, a sine wave profile, or any combination thereof.

A method, comprising:

• (a) for a first time period, providing one or more reactants in thermal contact with a first heating element in a reactor;
• (b) during a first part of a heating cycle, providing the one or more reactants with a first temperature by heating with the first heating element, such that one or more thermochemical reactions is initiated;
• and
• (c) during a second part of the heating cycle, providing the one or more reactants with a second temperature less than the first temperature,
• wherein a duration of the first time period is equal to or greater than a combined duration of the first and second parts of the heating cycle,
• the combined duration of the first and second parts of the heating cycle is less than five seconds,
• the first heating element operates by Joule heating and has a porous construction that allows gas to flow therethrough,
• the one or more thermochemical reactions comprises pyrolysis, thermolysis, synthesis, hydrogenation, dehydrogenation, hydrogenolysis, or any combination thereof, and
• the first heating element is formed as a porous membrane that allows one of a gaseous product and a reactant to pass therethrough to a second flow path while retaining the other of the gaseous product and the reactant in a first flow path.