GB1244879A - Process for the preparation of carbon black - Google Patents

Abstract

1,244,879. Carbon black. PHILLIPS PETROLEUM CO. 24 Dec., 1968 [29 Dec., 1967], No. 61364/68. Heading C1A. Carbon black is produced by a process comprising contacting a hydrocarbon reactant with a primary free oxygen-containing gas under carbon-black-producing conditions in an upstream region of a reaction zone, passing the reactant mixture downstream through the zone, quenching the mixture at the downstream end of the zone and recovering carbon black from the effluent from the zone, wherein a secondary free-oxygen containing gas is introduced into the zone downstream from the region in which the conversion of the reactant into carbon black is substantially complete but upstream from the point of quenching. The secondary gas is introduced in an amount sufficient to reduce the time required for detarring the carbon black to a tar-free carbon black having a photelometer value of at least 80. The primary gas is a hot combustion mixture produced by burning a fuel in the presence of an amount of oxygen in excess of that required for complete combustion of the fuel. The secondary gas is preferably air and is introduced in an amount of 2-50 volume per cent of the volume of primary gas. The secondary gas stream may also contain a vaporous fuel, the free oxygen in the secondary gas stream being less than that required to completely combust the fuel. The process can be carried out in known types of furnaces (see Figures not shown), with the reactant mixture passing axially through a generally cylindrical reaction zone. Preferably, the primary gas is formed as an annular gas stream flowing through the zone around an axial stream of hydrocarbon, the secondary gas being introduced tangentially. In another embodiment, some of the primary oxygen-containing gas is introduced tangentially into the upstream end where the hydrocarbon feed is introduced axially.