| 摘要 |
A three-stage process for cracking liquid or gaseous hydrocarbons into lower hydrocarbons and/or hydrogen, carbon monoxide and carbon dioxide comprises, in the first stage preheating the hydrocarbons by passing them alone or with steam up through a descending mass of hot heat-transfer material, in the second stage burning a part of the hydrocarbons with added oxygen or air so that the remainder is cracked by the heat evolved and finally in the third stage, cooling the gases produced by passing them up through the descending heat transfer material which has been withdrawn in a cool state from the first stage and recirculated to the top of the third stage. The three stages may be carried out in separate vessels but are preferably super-imposed in a single vessel, the heat transfer material, which may be any refractory and easily flowing granular substance but which preferably consists of naturally occuring pepples or pepples of alumina or mullite prepared artificially as described in Specification 715,882, being withdrawn from the bottom of the vessel after passing down through each stage in succession and then elevated to a feeding device at the top thereof. Hydrocarbons and steam are admitted at the bottom of the vessel and oxygen infected at about one third of its height. Cool gas is withdrawn at the top.
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