STUDIES OF CARBON BLACK: I. A NEW PROCESS FOR THE PRODUCTION OF CARBON BLACK BY THERMAL DECOMPOSITION OF HYDROCARBON GASES

Abstract

A method is described whereby carbon black is produced from hydrocarbon gases such as methane or propane-butane by thermal decomposition of these gases in a heated tube. The essential feature of the process is the use of a porous refractory tube through which a certain amount of inert gas is allowed to pass. By this means the reacting gas is unable to touch the walls of the system, and deposition of carbon thereon is prevented. Yields as high as 60% of the carbon in the gas, corresponding to 65 lb. per thousand cubic feet, have been obtained from a 70–30 propane-butane mixture, and 19 lb. from methane. The carbon black produced by this process is similar to the "soft" blacks in that it has a high density, low sorptive power, it accelerates the cure in a rubber stock and gives similar resistance to aging and abrasion. It imparts greater stiffness to a rubber stock, however, and in many ways occupies a position between the channel and the "soft" blacks.