非芳烃分离塔生产运行分析与改进措施

Analysis of Operation of Non-aromatic Separation Tower and Improvement Measures

长岭分公司重整车间的非芳烃分离塔在大检修时整体更换为处理能力为15t/h的新塔T311,但更换后,溶剂油总收率没有达到设计要求。对非芳烃分离塔进行技术标定,发现实际原料比设计原料稍重;6号、120号溶剂油的有效组分未得到充分回收,并且出现组分重叠现象,导致它们的产量与收率相对变化较大;汽油总收率为48.28%,远高于23.4%的设计值,溶剂油收率为51.65%,远低于76.6%的设计值。究其原因,主要是标定期间塔顶操作压力偏高,上部回流比偏小,分离精度未达到设计要求,另外一个原因就是进料中带入过多的轻汽油组分。为此,将抽提塔原料的初馏点温度由(62±2)℃提高至(65±2)℃,以减少原料中C5等轻组分含量,定期清洗塔顶空冷器,降低塔的操作压力两项改进措施。措施实施后,溶剂油总收率达到70.30%,比2007年同期提高了12.14%,增效644.64万元。

SINOPEC Changling Petrochemical Company replaced the non-aromatic separation tower in its reformer workshop with a new tower T311 with a processing capacity of 15t/h during an overhaul.However,the total yield of solvent naphtha failed to meet design requirements after the replacement.Technical calibration of the non-aromatic separation tower indicates that：the feedstock is slightly heavier than the feedstock in design;the effective components of 6# and 120# solvent naphtha were not fully recovered and there was component overlap,leading to relatively large change in their output and yield;the total yield of gasoline is 48.28%,far higher than the design value of 23.4%,and the solvent naphtha yield is 51.65%,far lower than the design value of 76.6%.The main reasons for these problems are the operating pressure at the top of the tower is excessively high during calibration,the reflux ratio at the upper section is excessively small and the separation accuracy did not meet design requirements.Another reason is that excessive light gasoline components are entrained in the feed.To solve these problems,technicians at Changling Petrochemical Company raised the initial boiling point temperature of the feed to the extraction tower to（65±2）℃ from（62±2）℃ to reduce the contents of light components such as C5.Other measures taken included cleaning the air cooler at the top of the tower on a regular basis and reducing the operating pressure of the tower.As a result of the imposition of these measures,the total yield of solvent naphtha reached 70.30%,12.14% higher than in the same period 2007 ,and economic benefits amounted to 6.4464 million Yuan.