Production of high surface area carbon blacks

In a modular process for producing furnace carbon blacks having higher than normal surface areas wherein a fuel and an oxidant are reacted in a first zone so as to provide a stream of hot primary combustion gases possessing sufficient energy to convert a carbon black-yielding liquid hydrocarbon feedstock to carbon black, and wherein in a second zone the liquid hydrocarbon feedstock is peripherally injected, in the form of a plurality of coherent jets, into the stream of gaseous combustion products in a direction substantially transverse to the direction of flow of the stream of combustion gases and under sufficient pressure to achieve the degree of penetration required for proper shearing and mixing of the feedstock, and wherein in a third zone the feedstock is decomposed and converted into carbon black prior to termination of the carbon forming reaction by quenching, and then cooling, separating and recovering the resultant carbon black, the improvement which comprises introducing water, in the form of vapor, in an amount of from about 4 to 15% by volume based on the total gaseous volume of the fuel and oxidant utilized in preparing the primary combustion, into the first zone such that the water vapor is well mixed with the stream of gaseous combution products prior to the introduction of the liquid feedstock, and maintaining the carbon black forming reaction in the third zone for a residence time of at least 0.5 seconds, and operating the process under conditions such that the overall percent combustion thereof ranges from about 40 to about 60 percent.