Abstract:

Aiming at the recovery and removal of residual solvents in the solvent extraction residues of heavy oil mines, a surfactant-enhanced bubbling separation process based on the bubbling separation process was proposed. The influence of surfactant types on the bubbling separation process was explored, and the kinetics of the anionic surfactant sodium dodecyl sulfate (SDS) on the bubbling separation process was studied. The results showed that the type of surfactant has an important influence on the removal effect. By reducing the toluene-water interfacial tension and increasing the hydrophilicity of the solid surface, the anionic surfactant SDS promoted the separation of the toluene liquid layer from the surface of the solid particles, thereby strengthening the bubbling separation process. The first-order kinetic model of the process was confirmed. However, the cationic surfactant tetradecyl trimethyl ammonium bromide (C₁₄TAB) and the amphiphilic surfactant lauryl betaine (SB-12) increased the hydrophobicity of the solid surface, which promoted the particled to leave the solution system and inhibited the progress of bubbling separation. But the degree of SB-12 modification on the solid surface was weaker than that of C₁₄TAB, so the inhibitory effect of SB-12 was weaker than that of C₁₄TAB. With the extension of the bubbling time, the change of toluene-water interfacial tension caused by SB-12 became the main factor affecting the effect of bubbling separation, the effect of SB-12 on the bubbling separation process changed from inhibition to enhancement. But C₁₄TAB always exhibited an inhibitory effect during the bubbling separation process. The above results had certain theoretical significance for the removal and recovery of residual solvents after similar solid-phase solvent extraction.

Key words: separation, surfactant, interfacial tension, process intensification, kinetic model

摘要：

针对重质油矿溶剂萃取残渣中残留溶剂的回收和去除问题，本文在鼓泡分离工艺的基础上提出了表面活性剂强化鼓泡分离工艺，探究了表面活性剂种类对于鼓泡分离过程的影响，并研究了阴离子表面活性剂十二烷基硫酸钠（SDS）对于鼓泡分离过程的动力学。结果表明，表面活性剂种类对去除效果具有重要影响：SDS可以通过降低甲苯-水界面张力和增加固体表面的亲水性，促进甲苯液层从固体颗粒表面的脱离，进而强化鼓泡分离过程，该过程符合一级动力学模型。然而，阳离子表面活性剂十四烷基三甲基溴化铵（C₁₄TAB）和双亲性表面活性剂月桂基甜菜碱（SB-12）则通过增加固体表面的疏水性，促使颗粒离开溶液体系，抑制了鼓泡分离的进行，但由于SB-12对固体表面改性的程度弱于C₁₄TAB，SB-12的抑制作用弱于C₁₄TAB，且随鼓泡时间的延长，SB-12对甲苯-水界面张力的改变成为影响鼓泡分离效果的主要因素，SB-12对鼓泡分离过程的影响由抑制转为强化，但C₁₄TAB在鼓泡分离过程中始终呈现抑制作用。上述结果对于类似的固相溶剂萃取后残留溶剂去除或回收具有一定的理论指导意义。

关键词: 分离, 表面活性剂, 界面张力, 过程强化, 动力学模型