Analysis of Liquefaction Product Oils from Fischer-Tropsch Synthesis Using Column Liquid Chromatography/Gas Chromatography

A two-step pretreatment method for analysis of Fischer-Tropsch cold trap oils by column liquid chromatography was developed. The first step was the separation of Fischer-Tropsch cold trap oils into paraffin-olefin fraction and oxygenates fraction by column liquid chromatography with silica gel of 80–100 mesh as a stationary phase and dimethylsulfoxide (DMSO) as the eluent. The second step was similar to the first one except that the pore diameter of silica gel was smaller (100–200 mesh), and the paraffin-olefin fraction was further separated into paraffins and olefins. Through this pretreatment, the cold trap oils were separated into three different groups, namely, paraffins, olefins and oxygenates. All preparation fractions were resolved by high-resolution-capillary column gas chromatography, respectively. Using pure reagents as standards, components of all the three separated groups were identified by comparing gas chromatography retention time and carbon number rule of samples with corresponding pure reagents. The components were then quantified by correction factor normalization method. On the basis of the above research, the results of 63 components were given in this article, which accounted for 80% of total peaks detected by GC. The results will benefit the development of Fischer-Tropsch synthesis process.