尾油循环的煤焦油加氢实验研究

Experimental research on coal tar hydrotreating of residue recycling

利用小型固定床加氢实验装置,将煤焦油和其加氢后的尾油混合,在温度(360~420)℃、压力(13~15)MPa、氢油体积比(1 500~1 700)∶1和液体体积空速0.25 h-1条件下进行加氢处理,所得产品切割得到的汽油馏分、柴油馏分和尾油馏分,分别占产物质量的16.12%、78.83%和5.05%,且产品中硫、氮含量很低,汽油中硫含量16.7μg·g^(-1),氮含量36μg·g^(-1),柴油中硫含量102.6μg·g^(-1),氮含量97μg·g^(-1),可用作清洁燃料。结果表明,尾油循环在煤焦油加氢过程中对煤焦油具有稀释作用,不仅减轻了设备负荷,同时也可以提高汽油和柴油收率。因此,以煤焦油加氢尾油循环加氢是一种高效、绿色环保制备燃料油的方法。

The hydrotreatment of the mixture of coal tar and its tail oil after hydrogenation was studied in a small fixed bed hydrogenation unit under the process condition as follows：reaction temperature （360 - 420 ）℃,reaction pressure （13 -15 ） MPa, volume ratio of hydrogen to oil （1 500 -1 700）： 1 and LHSV 0.25 h^-1. In the obtained product, mass fractions of gasoline, diesel oil and hydrogenation tail oil were 16.12% ,78.83% and 5.05% ,respectively. And the contents of sulfur and nitrogen in the product were very low. The contents of sulfur and nitrogen in gasoline were 16.7 μg·g^-1 and 36μg·g^-1, respectively. The sulfur content was 102.6 μg·g^-1 and the nitrogen content was 97 μg·g^-1 in diesel oil,which could be used as clean fuel. The results showed that the recycling of tail oil had dilute effect during coal tar hydrotreating, which not only reduced the load of equipment, but also enhanced the yield of gasoline and diesel oil. So coal tar hydrotreating of residue recycling was a kind of efficient and benignly environmental preparation method of fuel oil.