GB794157A - Process for the production of acetylene and ethylene - Google Patents

Abstract

<PICT:0794157/IV (b)/1> Acetylene and ethylene are produced by the partial combustion of methane and/or ethane at superatmospheric pressure in a combustion zone comprising a convergent section and a divergent section in contiguous relationship, the gases passing thence to a lower pressure zone within such time that substantially no decomposition or polymerization of acetylene occurs, the ratio of the entering pressure to the exit pressure in the combustion zone being between 1.5 : 1 and 10 : 1. Also preferably the effluent gases are exhausted from the combustion zone to a superatmospheric pressure and are further cooled with water prior to absorption of the acetylene and/or ethylene. The initial gases may be preheated before combustion. The combustion chamber takes the form of a nozzle known as a De Laval nozzle. Referring to Fig. 1, oxygen and hydrocarbon are passed from the storage tanks 1 and 2 respectively into the mixing chamber 9 filled with silicon carbide granules to assist in mixing. The gases pass thence to a combustion chamber 20 which contains a sparking-plug 19 to initiate combustion and a thermocouple 17 provided with a gauge 18. The combustion chamber has a convergent section 22, a throat 27 and a divergent section 23. Generally the velocity of the gases will be about sonic in the throat, in the converging section subsonic, and in the diverging section supersonic. The conditions used are preferably a mol. ratio of methane to oxygen of about 1 : 1, or ethane to oxygen about 2 : 3, using super-atmospheric pressure and a temperature between 1150 DEG and 1500 DEG C.