| 摘要 |
822,615. Combustible gases. GERHOLD, M. June 4, 1956 [June 7, 1955], No. 17168/56. Class 55 (2). In a process for converting gaseous or liquid hydrocarbons into gases consisting of low molecular weight carbon compounds and hydrogen the hydrocarbons are first cracked at a temperature of at least 500‹ C., preferably 600-750‹ C., in the presence of a cracking catalyst and the gaseous products of the cracking are reacted with oxidizing gases, preferably in the presence of a dehydrogenating catalyst and at a temperature of 700-900‹ C., to form the required gases. Steam, air or oxygen or mixtures thereof may be used as the oxidizing gas and it and the starting materials may be preheated. External heat may be supplied to the process, e.g. by causing an electric current to flow in the walls of the reaction chamber. Cracking catalysts which may be used are oxides of aluminium, magnesium, zinc, cadmium, silicon, boron, tin, lithium, titanium, beryllium, zirconium or molybdenum alone or mixed with each other. The cracking and dehydrogenating catalysts may be formed into shaped heattransmitting bodies which may be heated to the desired reaction temperature outside the reaction chamber in which they are employed and circulated therethrough. The contact time for the whole process may be less than 15 seconds, e.g. 3-10 seconds, 1/2-1/3 of this time being employed for the cracking stage. Olefins which may comprise 30-50% of the products of the cracking stage may be separated therefrom and the residual gases only passed to be reacted with the oxidizing gases. Hydrogen in an amount up to 10% by weight of the starting material may be introduced into the cracking stage, e.g. by recycling some of the final gas produced to the cracking stage.
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