Abstract: A reaction system comprises a reactor vessel, a secondary vessel, a transfer line providing fluid communication between the reactor vessel and the secondary vessel, a return line providing fluid communication between the secondary vessel and the reactor vessel, a filter disposed within the secondary vessel, and at least one freeze plug valve disposed within the transfer line or the return line.

Abstract: A heat transfer media comprises a particle. The particle comprises a discontinuous phase and a matrix material. The discontinuous phase is disposed within the matrix material, and the matrix material has a higher melting point than the discontinuous phase. The discontinuous phase has a melting point selected to be within a reaction temperature range.

Abstract: A reaction process includes introducing hydrocarbon reactants into a vessel, reacting the hydrocarbon reactants in contact with the gas phase catalyst in the vessel to produce reaction products comprising solid carbon and a gas phase product, separating the solid carbon from the gas phase products and the gas phase catalyst to produce a solid carbon product, condensing the gas phase catalyst to produce a condensed catalyst, and returning the condensed catalyst to the liquid catalyst reservoir. The vessel comprises a gas phase catalyst and a liquid catalyst reservoir containing a liquid catalyst.