超声强化C8芳烃中乙苯结晶分离工艺研究

Research on Ultrasonic Enhanced Separation of Ethyl benzene,Crystals from C8 Aromatic Hydrocarbons

通过改变超声波的功率,研究不同功率超声波对C8芳烃异构体形貌以及动力学行为的影响。研究结果表明,将40 W、20 kHz超声波引入C8芳烃结晶分离过程,不仅可以避免晶体的爆发成核,使形成的晶体形貌变为尺寸更小、更加规整的球形颗粒,不易包藏母液,从而提高C8芳烃中乙苯组分分离效率,使二甲苯晶体的含湿率降低至2%;同时大幅降低结晶分离所需的冷量,使混合C8芳烃物料初次析晶温度由-47.2℃提升至-8.9℃,提高结晶分离二甲苯晶体后的乙苯母液纯度至99.0%,从而实现乙苯的单级高效连续结晶分离,生成出能够直接进入苯乙烯装置的高浓度、高纯度乙苯。

By changing the power of ultrasonic waves,the effects of different power ultrasonic waves on the morphology and dynamic behavior of C8 aromatic isomers were studied.The research results indicate that introducing 40W and 20 kHz ultrasonic waves into the C8 aromatics crystallization and separation process can not only avoid crystal nucleation,but also transform the formed crystal morphology into smaller and more regular spherical particles,making it diffi cult to encapsulate the mother liquor,thereby improving the separation effi ciency of ethylbenzene components in C8 aromatics and reducing the moisture content of xylene crystals to 2%;At the same time,the required cooling capacity for crystallization separation is signifi cantly reduced,increasing the initial crystallization temperature of the mixed C8 aromatic materials from-47.2℃to-8.9℃,and increasing the purity of the ethylbenzene mother liquor after crystallization separation of xylene crystals to 99.0%,thereby achieving singlestage efficient and continuous crystallization separation of ethylbenzene,generating high concentration and highpurity ethylbenzene that can directly enter the styrene unit.