The invention relates to approach temperatures and approach temperature ranges that are beneficial in operating a pyrolysis reactor, to pyrolysis reactors exhibiting a beneficial approach temperature, to processes for carrying out hydrocarbon pyrolysis in a pyrolysis reactor having a beneficial approach temperature. The pyrolysis reactor can be, e.g., a reverse-flow pyrolysis reactor, such as a regenerative reverse-flow pyrolysis reactor.

The invention relates to hydrocarbon dehydrocyclization to produce products such as aromatic hydrocarbon, to equipment and materials useful for dehydrocyclization, to processes for carrying out dehydrocyclization, and to the use of dehydrocyclization for, e.g., natural gas upgrading. The dehydrocyclization is carried out in a catalytic reaction zone of a reverse-flow reactor.

One embodiment of the present invention is a unique method for operating a fuel cell system. Another embodiment is a unique system for reforming a hydrocarbon fuel. Another embodiment is a unique fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and steam reforming systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

One embodiment of the present invention is a unique method for operating a fuel cell system. Another embodiment is a unique system for reforming a hydrocarbon fuel. Another embodiment is a unique fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and steam reforming systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

The invention relates to hydrocarbon dehydrocyclization to produce products such as aromatic hydrocarbon, to equipment and materials useful for dehydrocyclization, to processes for carrying out dehydrocyclization, and to the use of dehydrocyclization for, e.g., natural gas upgrading. The dehydrocyclization is carried out in a catalytic reaction zone of a reverse-flow reactor.