2. Raw Material and Separation Scheme
2.1. Raw material characteristics
The raw material was the mixture of products from a Fisher–Tropsch synthesis with a Co-based catalyst. The qualitative and quantitative analyses for the raw material were performed with the gas chromatographic method. The composition of the raw material and the normal boiling point [17] of each component are listed in Table 1. The primary alcohols account for a weight ratio of 43.98% and the saturated alkanes account for 56.02% of the raw material. The lowest normal boiling point (36.3 °C) is for n-pentane and the highest (356.5 °C) is for n-heneicosane, accounting for the wide boiling range of the raw material. The saturated alkanes are non-polar, whereas the primary alcohols are polar or weakly polar. Methanol has the strongest polarity and the polarity of alcohols decreases as the number of carbon atoms increase. The polarity of C18-alkyl alcohols is so weak that it can form a stable and homogeneous solution with the non-polar saturated alkanes.