Abstract: A process for producing carbon black by utilizing a reactor comprising a first gradually constricted reaction zone in which a mixture of a fuel and an oxygen-containing gas, is burned, a second gradually constricted reaction zone having a throat in which the resulting high temperature combustion gas is mixed and reacted with a hydrocarbon feedstock, and a third reaction zone provided with a quenching water spray for terminating the reaction, which comprises directing the high temperature combustion gas formed in the first reaction zone to form an axial stream flowing in substantially the same direction as the axial direction of the reactor, introducing the divided axial streams into the second reaction zone, and, in the second reaction zone, introducing the hydrocarbon feedstock from nozzles in a direction traversing the axial streams of the high temperature combustion gas.

Abstract: A process for producing carbon black in a reaction system comprising a first zone where a heating fuel material and an oxygen-containing gas are mixed, and a high temperature combustion gas stream is formed, a second zone where a hydrocarbon starting material is mixed to the high temperature combustion gas stream to form carbon black, and a third zone subsequent to and down-stream of the second zone, where the carbon black thus formed, is contacted with an activating agent to activate the carbon black, characterized in that steam is introduced as an activating agent to the third zone.