苯抽提装置运行问题及解决措施

中国石油哈尔滨石化公司苯抽提装置采用SUPER SAEⅡ专利工艺技术设计建造,设计处理能力为10×104t/a。该装置在运行过程中,先后出现了原料甲苯超标、进料负荷偏低、原料苯含量严重偏低、产品苯酸洗比色超标、非芳烃含量偏高、抽余油中环丁砜含量超标等问题,不仅严重影响了装置的稳定运行,也严重影响了苯和抽余油产品的产品质量。通过分析问题原因,采取了有针对性的解决措施:加强原料性质的监控,严格控制原料中甲苯含量不超标;将抽提塔进料量提至9.0～9.5t/h;利用已有流程将精制前苯部分转入返洗剂罐,将0.5t/h的苯添加至返洗液中,提高了返洗液中的苯含量;投用白土塔。通过采取应对措施,逐步稳定了产品质量,使外输苯产品质量一直能达到并超过GB 3405—1989国家优级苯标准。

Operation Problems of Benzene Extraction Units and Solutions

PetroChina Harbin Petrochemical Company adopted the SUPER SAE II patented technology in designing and constructing its benzene extraction unit,which has a designed processing capacity of 10×104t/a.The unit met with many problems during operation,including too high content of methylbenzene in feedstock,too low load of feeds,extremely low content of benzene in feedstock,too high benzoic acid colorimetry result,too high contents of non-arene substance and too high content of sulfolane in raffinate oil.These problems not only greatly affected the stability of operation of the unit but also impacted the quality of benzene and raffinate oil.After analyzing the causes of the problems,technicians came up with solutions,including strengthening the monitoring of feedstock properties,strictly controlling the content of methylbenzene in feedstock to maintain it within the normal range,raising the feeding rate for the extraction tower to 9.0-9.5t/h,transmitting the benzene stream before refining through the existing process to the return lotion tank and adding 0.5t/h of benzene into the return lotion to raise the content of benzene in the return lotion,and introducing a carclazyte column.As a result of these measures,the product quality of the unit stabilized and has never dropped below the GB 3405—1989 national standard for premium benzene products.