催化汽油加氢脱硫装置分离塔的优化调整分析

Optimal adjustment analysis on splitter of FCC gasoline hydrodesulfurization unit

关键词:  催化汽油加氢脱硫装置  分离塔  优化

Key words:  FCC gasoline hydrodesulfurization unit  splitter  optimization

摘要:

催化汽油加氢装置进行国Ⅴ改造后,选择性加氢单元分离塔存在分割精度不高、回流比低、控制回路自控率低和轻汽油在线硫分析仪控制滞后等问题。通过分析原因,提出了变更轻汽油在线硫组态控制、重新整定控制回路PID参数和优化分离塔工艺参数等措施。上述措施实施后,分离塔塔底油10%馏出温度与轻汽油90%馏出温度的温度差提高到40 ℃以上,分离塔分割精度提高,轻汽油抽出比例提高了3百分点,终馏点为65~67 ℃,满足醚化装置要求,分离塔塔顶压力从0.89 MPa降至0.81 MPa。在处理量相同的情况下,分离塔重沸炉出口温度降低8~10 ℃,重沸炉燃料气用量降低190 m³/h,经济效益显著。 

Abstract:

After the transformation of FCC gasoline hydrogenation unit according to national standard of grade V gasoline, some problems of the splitter of selective hydrogenation unit arose, such as low separation accuracy, low reflux ratio, low automatic control rate of the control loop and control lag of on-line sulfur analyzer for light gasoline(LCN). Through analyzing the reasons, it was proposed to change the on-line sulfur configuration control of LCN, re-adjust PID parameters of control loop, and optimize the splitter process parameters, and so on. After above measures were carried out, the temperature difference between 10% range of HCN and 90% range of LCN increased to over 40 ℃, the segmentation precision of splitter improved, and the LCN withdrawal ratio increased by 3 percentage points. The FBP of LCN was 65-67 ℃, which could meet the requirements of etherification unit. The top pressure of splitter decreased from 0.89 MPa to 0.81 MPa. In the case of same processing capacity, the outlet temperature of splitter reboiler furnace reduced 8-10 ℃, and the fuel gas consumption of the reboiler furnace reduced 190 m³/h. The economic benefit was notable.