GB264845A - Improvements in and relating to the conversion of saturated hydrocarbons, in gas or vapour form, especially methane, into unsaturated hydrocarbons - Google Patents

Abstract

264,845. I. G. Farbenindustric Akt.- Ges. Jan. 20, 1926, [Convention date]. Hydrocarbons; benzene; acetaldehyde. - The thermal decomposition of gaseous or vaporous saturated hydrocarbons, particularly methane, into unsaturated hydrocarbons, particularly acetylene. is effected by passing the saturated hydrocarbons, alone or diluted with nitrogen or other inert gases, through a flame which extends across substantially the whole cross-sectional area of a tube. The flame may be a disc-like flame produced by burning a combustible gas, such as a part of the gas to be treated, with air &c. in a plurality of separate burners. The reaction products may be rapidly cooled to separate the hydrocarbons, or they may be subjected directly to further chemical treatment to vield other products, such as benzene or acetaldehyde. The residual gases containing hydrogen and carbon monoxide may be converted catalytically into methane, which may be returned to the process. Suitable apparatus comprises an inlet tube E for the gas to be treated having branches m and a main branch R controlled by taps F, g. The branches m lead to burners i arranged radially in a horizontal plane, as shown in Fig. 2, and projecting into a reaction tube K; the burners have flattened nozzles and are fed with air &c. through pipes h. In use, the burners are lit by an ignition device (not shown), such as an induction sparking apparatus, and the main part of the gas to be treated flows through the tube R and then through the disc of flame produced by the burners. The reaction products preheat the gases flowing in the tube R and are withdrawn through a pipe S. The air &c. and/or the combustion gas may be preheated, preferably by exchange of heat with the reaction products. The Specification as open to inspection under Sect. 91 (3) (a) states that the thermal decomposition may be effected in a zone of high temperature obtained by the flameless combustion of part of the gas to be treated. In this connection a modified apparatus is described in which the burners i are replaced by 32 radially disposed oxygen-delivering nozzles and in which the reaction tube is fitted internally, at the level of the nozzles, with a horizontally arranged gauze of tungsten wire covering the whole cross-section of the tube and supporting a thin layer of platinized asbestos. A further modification is described also in which the platinized asbestos is replaced by a plate of highly porous refractory material, such as " Marquardt composition," mounted about 1 cm. below the nozzles. This subject-matter does not appear in the Specification as accepted.