芳烃抽提装置腐蚀问题分析及解决方法研究

针对以环丁砜为溶剂的芳烃抽提装置存在的腐蚀问题，通过现场调研，分别从工艺条件、原料性质及溶剂3个方面分析腐蚀产生的条件和特点，分析腐蚀垢样的成分，模拟芳烃抽提工艺，分别设计吸附、氯离子分配、腐蚀、溶剂再生等试验，研究腐蚀原因和解决方法。研究结果表明：环丁砜的分解产物和原料中的氯是造成腐蚀结垢的主要原因；阴离子交换树脂可以有效改善溶剂pH，减少腐蚀；氯离子在再生塔塔底富集，定期清理再生塔塔底残液可有效降低溶剂氯含量，有利于解决腐蚀问题；采用不锈钢材质是有效的缓蚀方法。

ANALYSIS AND SOLUTION OF CORROSION PROBLEM IN AROMATICS EXTRACTION UNIT

Aiming at the corrosion problem of sulfolane-solvent-based aromatics extraction unit, the conditions and characteristics of corrosion were analyzed from three aspects: process conditions, raw material properties and solvents through field investigation. The composition of corrosion samples was analyzed and the aromatics extraction process was simulated. Simulation of adsorption, chloride ion distribution, corrosion and solvent regeneration were conducted to find the solutions. The results showed that the sulfolane decomposition products and the chlorine in raw materials were the main causes for corrosion; anionic resin could effectively improve the pH value of solvents and reduce corrosion; chloride ions were mainly concentrated at the bottom of regeneration tower. Regular cleaning of the residual liquid at the bottom of regeneration tower could effectively reduce the chlorine content of solvents, which is conducive to solving the corrosion problem. It is concluded that using stainless steel can prevent corrosion effectively.