Solar-thermal fluid-wall reaction processing

Carbon black produced by a method comprising the steps of:

• a) providing a reactor comprising at least two reactor shells, including an innermost and an outer shell, wherein the innermost shell is substantially enclosed by each of the other reactor shells, has an inlet and an outlet and is at least partially porous and the outer shell is nonporous and at least partially transparent;
• b) flowing a first gas stream comprising at least one hydrocarbon reactant gas from the inlet to the outlet of the innermost shell;
• c) flowing a second gas stream comprising a non-dissociating gas inwardly through the pores of the innermost shell;
• d) providing heat absorbing particles in the first gas stream;
• e) heating the heat absorbing particles at least in part with a source of concentrated sunlight through indirect solar thermal heating;
• and
• f) transferring heat from the particles to the first gas stream, thereby heating the reactant gas to a sufficiently high temperature so that a desired amount of conversion of the reactant gas occurs, thereby producing hydrogen and carbon black,
• wherein the carbon black is substantially free of ash and is substantially amorphous.