Abstract:

It introduces the main production situation of the 1.20 MM TPY hydrofining unit. The reasons for the excessive sulfur content in the products of the hydrofining unit are analyzed from the aspects of changing the reactor reaction temperature, product circulation and other process operating conditions, as well as the sampling data at the outlet of the high-pressure heat exchanger. Energy dispersive spectrometer and X-ray diffractometer(XRD) detected that the blockage of high-pressure heat exchanger was corrosion under the deposited scale of ammonium salt(NH₄Cl), resulting in internal leakage of high-pressure heat exchanger E6101 C after the unit was converted to 0^# diesel. Through the process management and control such as material upgrading, increasing water injection, increasing the temperature of high-pressure heat exchanger E6101 C and so on, the heat exchanger was treated protectively, and the solution measures were put forward for the corrosion under the scale, so as to ensure the long-term stable operation of the heat exchanger. The mass fraction of total sulfur in 0^# diesel was continuously lower than 8 μg/g, and the product met the requirements of Guo Ⅵ standards.

Key words: hydrofining unit, product sulfur content, diesel circulation, reaction temperature, high-pressure heat exchanger, internal leakage

摘要：

介绍了1.20 Mt/a加氢精制装置主要生产概况，并从改变反应器反应温度、产品循环量等工艺操作条件及高压换热器出口采样数据等方面对该装置产品硫含量超标原因进行了分析。通过能谱仪、X射线衍射仪(XRD)检测出高压换热器堵塞物为铵盐(NH₄Cl),且铵盐结晶沉积在设备内部，长此以往堵塞部分管束，引起铵盐垢下腐蚀，导致高压换热器E6101C在装置转产0号柴油后出现内漏。通过材质升级、增加注水量、提高高压换热器E6101C温度等工艺管控对换热器进行保护性处理，并对垢下腐蚀提出了解决措施，从而保证换热器长周期稳定运行，产品0号柴油硫的质量分数持续低于8μg/g,产品符合国Ⅵ标准要求。

关键词: 加氢精制装置, 产品硫含量, 柴油循环量, 反应温度, 高压换热器, 内漏