热萃取污油的降凝处理研究

Study on pour point decreasing of the polluted oil obtained oily sludge by thermal extraction technology

经热萃取从含油污泥中得到的回收污油凝固点高、流动性差,为降低凝点改善其低温流动性,分别采用降凝剂及降凝剂与超声波联合处理的方法,对回收污油进行降凝处理.结果表明:在众多降凝剂中EVA的降凝效果较好,且当反应时间为0.5 h、反应温度为75℃、降凝剂的质量浓度为400 mg/L时,污油凝点从48℃降低到12℃,降凝率达75%;若将降凝剂和超声波联合使用,凝点可降到5℃,降凝率达90%;处理后的污油与原油混合具有良好的输送性能.

The polluted oil is characterized by high pour point and poor flowability.In order to decrease its pour point and improve its flowability at low temperature,the polluted crude oil was treated by different depressants and ultrasonic wave separately,and by the combination of screened depressant with ultrasonic wave.It is shown that,depressant EVA has better pour point decreasing effect than other depressants,and when the reaction time is 0.5 h,temperature is 75 ℃ and its mass concentration is 400 mg/L,the freezing point of the polluted oil can drop from 48 ℃ to 12 ℃ and the pour point decreasing ratio reaches to 75%.Furthermore,the pour point is decreased to 5 ℃ and the pour point decreasing ratio reaches to 90% when the depressant EVA is combined with ultrasonic wave.The mixture of the treated polluted oil and crude oil has excellent transport performance,and it can meet the demand of transport properties of crude oil.