费-托合成蜡分质分级-萃取精制工艺研究

以内蒙古伊泰费-托合成蜡为原料,采用减压蒸馏与溶剂萃取相结合的工艺技术脱除费-托合成蜡中的异构烃类和含氧化合物以降低其油含量。考察了不同萃取剂、操作条件对脱油效果的影响,采用傅里叶红外光谱(FT-IR)和高温气相色谱对蜡样品进行分析。结果表明:选用N-甲基吡咯烷酮为溶剂,在萃取温度为120℃、剂油质量比为2.0的操作条件下,萃取效果最佳,精制蜡收率和含油率分别为93.75%和0.097%,精制蜡滴点为112℃,针入度为0.1mm,产品满足Sasol公司H105费-托合成蜡产品质量标准。精制费-托蜡的碳数分布在C₁₉～C₁₂₀之间,FT-IR表征结果表明其结构简单,主要由长链正构烷烃组成,C₃₅的含量最高。

STUDY OF PROCESSING FISCHER-TROPSCH WAXES BY VACUUM DISTILLATION AND EXTRACTION REFINING

This paper introduced a method of refining Inner Mongolia Itai Fischer-Tropsch waxes to reduce oil content. The method removed iso-hydrocarbons and oxygenate by combining process of vacuum distillation and solvent extraction. The effects of the extraction agent, the conditions of extraction on the removal efficiency were investigated. The Fourier transform infrared spectroscopy (FT-IR) and High temperature gas chromatography simulated distillation were applied to analyze the Fischer-Tropsch waxes. The results showed that the yield of Fischer-Tropsch waxes and oil content can reach 93.75% and 0.97‰, respectively by using N-methyl pyrrolidone as solvent, extraction temperature of 120℃, catalyst/oil ratio of 2:1. At this point, the refined wax has a melting point of 112°C and a penetration of 0.1mm. The product satisfies the quality standard of H105 Fischer-Tropsch wax produced by Sasol. The carbon number of refined F-T waxes is distributed between C19 and C120, and FT-IR characterization showed that it is simple in structure, mainly composed of long chain n-alkanes, among which the content of C35 is the highest.