GB678243A - Process for producing carbon black and valuable by-product gases - Google Patents

Abstract

In the production of carbon black by the thermal decomposition of hydrocarbons where an oxygen containing gas and a fuel or carbon monoxide are burned to provide heat for the decomposition, the oxygen containing gas is a mixture of pure oxygen and from 3.9 to 6.3 volumes of a heat absorbing gas such as carbon dioxide, carbon monoxide, water vapour or hydrogen per volume of oxygen. Nitrogen is substantially excluded and the resulting gaseous products after separation of the carbon black, and consisting mainly of carbon monoxide, hydrogen and carbon dioxide are suitable for synthesis processes, the carbon dioxide being removed by washing with triethanolamine; they may also be recycled to provide fuel for the thermal decomposition. If hydrogen or carbon monoxide is employed both as the fuel and the heat absorbing gas, sufficient is present to react completely with the oxygen, plus an excess which constitutes the heat absorbing gas. A temperature of 1200 DEG to 1900 DEG C is preferably maintained in the reaction zone. Before separation of the carbon black cooling may be effected by the injection of water or by natural radiation, but preferably by the injection of cooled heat absorbing gases such as hydrogen, carbon monoxide, carbon dioxide, water vapour or a mixture thereof such as the cooled combustion products recovered in the process. Specification 672,074 is referred to in this connection.