| 摘要 |
In the delayed coking of a coking feedstock wherein the feedstock is continuously heated in a coking heater 35 and introduced into a coke drum 36, the heater is operated to provide a coke drum temperature of from 415 DEG to 455 DEG C, and, after filling of the drum to the desired level, feedstock introduction is discontinued and the coke-drum placed off-steam (36') and the coke drum contents are heated at a temperature of 450 DEG C to 500 DEG C, which temperature is at least 10 DEG C greater than the coking temperature, by passing a non-coking vapour 101 through the contents of the drum to reduce the volatile combustible matter content to a value of 4% to 10% by weight and thereby reduce the CTE of the formed coke. The process is applicable to the production of needle coke in particular from a petroleum feedstock wherein the feedstock is initially treated by thermal soaking in the presence of sulphur, followed by thermal cracking to increase the aromaticity. Noncrystalline substances may be removed prior to coking to further improve the process. <IMAGE> |
