石脑油加氢装置改造为催化裂化汽油预加氢装置及其运行分析

REVAMP OF NATHPHA HYDROGENATION UNIT FOR FCC GASOLINE PREHYDROTREATING AND OPERATION ANALYSIS

为降低FCC汽油的硫醇、二烯烃含量,采用中国石油石油化工研究院开发的FCC汽油预加氢技术,将一套200kt/a石脑油加氢装置改造成250kt/a FCC汽油预加氢装置。对原石脑油加氢装置的反应器进行了缩径处理,并增设了原料过滤器、聚结脱水器、原料缓冲罐气封等设施。改造后的FCC汽油预加氢装置的运行结果显示,FCC汽油的硫醇硫质量分数从26.1μg/g降到了2.7μg/g,二烯值从0.64gI/(100g)降到了0.20gI/(100g),预加氢产品的辛烷值没有损失。通过采取单炉管进料、瓦斯流量精确控制以及加强聚结脱水器压差监控等措施解决了反应器入口温度大幅度波动、原料聚结脱水器堵塞等问题,可为其它类似装置的改造和建设提供经验和参考。

In order to decrease the content of mercaptans and diolefins in FCC gasoline, an existing 0.2 Mt/a naphtha hydrogenation unit was revamped to a 0.25 Mt/a FCC gasoline prehydrotreating unit, which adopts a FCC gasoline prehydrotreating technology developed by Petrochemical Research Institute of CNPC. The revamping includes decreasing the inner diameter of naphtha hydrotreating reactor, increasing stock strainers, a coalescence dehydration device, and adopting gas seal for feed buffer tank. The performance test show that the mercaptans content in FCC gasoline is reduced to 2.7 μg/g from 26.1 μg/g, the diolefin value is lowered to 0.20 gI/（100 g） from 0.64 gI/（100 g） and no octane number loss is observed. Thought the reactor inlet temperature fluctuation and the block of coalescence dehydra- tion device were observed during the operation after revamping, the problems were solved by adopting single-tube furnace for feeding, controlling accurately the gas flow and the pressure difference of coales- cence dehydration device.