超声尿素包合法分离测定重质油中的正构烷烃

SEPARATION AND DETERMINATION OF NORMAL PARAFFINS IN HEAVY OIL WITH ULTRASONIC UREA ADDUCTION METHOD

选用大庆减压馏分油为原料,通过超声尿素包合法准确地分离了其中的正构烷烃和非正构烷烃组分,得到了纯度较高的正构烷烃。采用GC／MS进行了分析验证,测得正构烷烃的碳数范围为C20-C38。研究了活化剂、溶剂、尿素用量、温度、超声时间等因素对正构烷烃分离效果的影响,确定了最佳反应条件。在选定的反应条件下,2 g大庆减压馏分油,加入15 mL异丙醇,3 g尿素,正构烷烃的平均收率为42．51％。该方法准确度高,重复性好,正构烷烃定量分离的相对标准偏差为0．54％。

Normal paraffins were separated from Daqing vacuum gas oil （VGO） by urea adduction with the presence of ultrasonic field and activating agent. It was found that the carbon number of the separated normal paraffins was in the range of 20438 with relatively high purity as identified by the GC/MS data. Factors affecting the separation result, such as reaction temperature, reaction time, the type of activating agent and solvent, the amount of urea used, were discussed and the optimal reaction conditions were selected. Under the selected reaction conditions, 15 mL of isopropanol and 3 g of urea were added to 2 g of Daqing VGO, an average normal paraffin yield of 42.51% was obtained. This separation method possessed the features of high accuracy and good repeatability, having a relative standard deviation of less than 0.54%.