Patent No. U.S. 7,655,209 B2
Cabot Corporation has received a patent for a furnace carbon black producing process comprised of the steps of (a) obtaining off-gas from a carbon black furnace, (b) dewatering and heating the off-gas and substantially removing any existing carbon black therefrom to obtain dewatered and heated off-gas, and then (c) feeding a combustion gas feed stream comprising the dewatered and heated off-gas and feeding an oxidant gas stream comprising an oxidant gas to a burner portion of a carbon black furnace, wherein the carbon black furnace to which the combustion gas feed stream and oxidant gas feed stream are fed is a different carbon black furnace from the carbon black furnace of step (a), wherein the carbon black furnace to which the combustion gas feed stream and oxidant gas feed stream are fed is comprised of the burner portion wherein a combustion gas feed stream is combusted in the presence of an oxidant gas feed stream to produce hot combustion gases and a reactor portion downstream of the burner portion wherein the hot combustion gases interact with a hydrocarbon feedstock to produce carbon black, (d) controlling the combustion gas feed stream and oxidant gas feed stream so that combustion of the combustion gas feed in the burner portion to produce hot combustion gases takes place in a fuel-rich condition so that the combustion gas feed stream does not completely combust in the burner portion, and (e) producing carbon black in the reactor portion of the carbon black furnace by interaction of the hot combustion gases with a hydrocarbon feedstock under the fuel rich conditions, wherein in carrying out step (e), a hydrocarbon feedstock is supplied to the reactor portion by feeding the hydrocarbon feedstock to a passage between the burner portion and the reactor portion of the carbon black furnace.