Process for the production of olefines of low molecular weight, more especially ethylene

摘要

In a process for the production of low molecular weight olefines, particularly ethylene, from liquid hydrocarbons by thermal cracking at a temperature above 750 DEG , preferably 850 DEG C., heat is continuously supplied to ceramic heat carriers by the direct introduction of flue gases containing, if any, no more than 2 per cent, preferably 0.5-1 per cent by volume of free oxygen and obtained by burning any fuel. The flue gases may form all or part of the carrier gas for the hydrocarbon. The flue gases can be formed in a separate chamber 11 in which case part of the flue gases may be led through pipe 16, cooled, if necessary, by cold gases introduced through pipe 18, so that the heat carrier bed is hotter than the mixture of hydrocarbon and carrier gas, and mixed with atomized or vaporized hydrocarbon which has been preheated in container 1. The remaining flue gases enter through 10 to heat the heat carriers in the reaction bed 8. Alternatively the flue gases are formed in situ in a space above the heat carriers and the liquid hydrocarbon is sprayed into the flue gas. In this case the fuel which is preferably gaseous is mixed with oxygen or oxygen-containing gas and burned with a short flame. Other carrier gas may be introduced with the fuel. Methane and hydrogen formed in the cracking process may be separated from the olefines and used as fuel for the production of the flue gases.