炼油厂含苯系物污水处理工艺模拟研究

Study on Treatment Process of Sewage Containing BTEX Based on Simulation

为了实现炼油厂含苯系物污水的回收利用,提出了液液萃取-汽提联合处理工艺。应用Aspen Plus对该工艺流程进行模拟,采用UNIQUAC物性方法,分析了抽余油用量、汽提蒸汽量等主要工艺参数对污水处理效果的影响。模拟结果表明,含苯系物污水经联合工艺处理后,净化水主要污染物含量低于饮用水标准限值,可作为新鲜水供炼厂回用;抽余油萃取了污水中的油和苯系物之后,依然满足该炼油厂对抽余油的质量要求,可按原计划送往下游装置。本工艺过程未产生二次污染,达到零排放的环保目标。

In order to recycle the wastewater containing benzene,toluene,ethylbenzene and xylene(BTEX)from the refinery,a combined process consisting of Liquid-liquid Extraction(LLE)followed by Steam Stripping(SS)is proposed.Aspen Plus is used to simulate this combined process and the property method is specified as UNIQUAC to analyze the effect of aromatics extraction raffinate oil flow rate and stripping steam flow rate on wastewater treatment.The result shows that the major pollutants in the treated water meet the requirements of the standard GB 5749,and the water can be reused by the refinery.After the treatment process,the raffinate oil used as extractant still satisfies the quality requirement of the refinery.Therefore,the zero emission target is achieved by the combined process.