炉管注入介质对延迟焦化过程的影响

研究了加热炉炉管注入不同介质对延迟焦化过程产品分布和产品性质的影响。中型试验结果表明:在进料量、炉出口温度、焦炭塔塔顶操作压力、循环比和生焦周期等操作条件基本一致的情况下，当注入介质由1%（w）水蒸气替换为相同物质的量的甲烷、乙烷和丙烷时，产品分布基本相当；当甲烷注入量（w）由1.04%提高至1.96%和4.02%时，焦化蜡油的产率分别提高了1.16百分点和3.44百分点，使得液体收率分别增加了0.75百分点和2.19百分点；随着甲烷注入量的提高，产品汽油馏分和柴油馏分的性质基本一致，但焦化蜡油的性质略差，主要表现在密度、残炭和沥青质含量均有所升高，95%馏出温度提高了21.9 ℃；同时当炉管内水蒸气和甲烷的注入量（w）相同时，采用甲烷比水蒸气更有利于减缓炉管结焦。

EFFECTS OF INJECTED MEDIUM ON DELAYED COKING PROCESS

The effect of different injected medium on the product distribution and product properties of delayed coking was investigated. The results of pilot test showed that when the injected medium of 1% steam was replaced by the same amount of methane, ethane or propane, the product distribution was nearly equal under the conditions that the feed rate, furnace outlet temperature, operating pressure, circulation ratio and coking period were basically the same. When the amount of methane injection raised from 1.04% to 1.96% and 4.02%, the yield of coker gas oil increased by 1.16 and 3.44 percentage points, respectively, and the yield of liquid products increased by 0.75 and 2.19 percentage points, respectively. With the increase of methane injection, the properties of coker gasoline and coker diesel were basically the same, but the properties of coker gas oil became worse. The density, residual carbon and asphaltenes content all increased, and its 95% point of the distillation range increased by 21.9 oC. Moreover, when the injection mass of steam and methane was the same, methane was more conducive to retard the furnace tube coking than steam.