###### Abstract  
A gas chromatography high temperature simulation distillation (HTSD: ASTM D 7169), and physical vacuum distillation (ASTM D 1160) were employed to characterize H-Oil vacuum distillates, straight run vacuum distillates, and hydrotreated vacuum distillates with the aim to determine their content of diesel fraction and evaluate the possible higher extraction of diesel fraction from the heavy oils. The ASTM D 7169 reported about six times as high diesel fraction content in H-Oil heavy distillates as that reported by the ASTM D 1160 method. Performing a commercial distillation column test along with a simulation of the column operation using data of both ASTM methods and a software process simulator revealed that the HTSD is the more valid method for proper determination of the diesel fraction content in heavy oils. The software process simulation of the commercial distillation column operation suggests that the HTSD could be considered as a true boiling point distillation method for heavy oils. The separation of the diesel fraction from the H-Oil heavy distillates quantified by the HTSD could deliver oil refining profit improvement in the amount of six digits USD per year. gas chromatography; simulated distillation; vacuum distillation; process simulation; diesel fraction +
Footnote †: journal: Applied Sciences  
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methods ASTM D 1160 and ASTM D 5236 [20]. Nevertheless, the suppliers of simulated distillation gas chromatography equipment provide correlations to convert the simulated distillation data into the physical distillation methods ASTM D 86 and ASTM D 1160 for more convenient use by the refiners. While the GC simulated distillation ASTM D 2887 was proved to be equivalent to the true boiling point (TBP) distillation according to the standard ASTM D 2892 [24] for light oils, the high temperature simulated distillation HTSD (ASTM D 7169) has not yet proved its equivalency to the TBP distillation for heavy oils. The different boiling point distributions reported by the HTSD and the ASTM D 1160 raise the following question: which distillation method provides more reliable and valid information about the remaining amount of the more valuable light oil in the less valuable heavy oil? Figure 1 illustrates the lower yield of diesel fraction in samples of heavy oils (atmospheric residue, straight run vacuum distillate, hydrotreated vacuum distillate, H-Oil heavy atmospheric gas oil (HAGO), light vacuum gas oil (LVGO), heavy vacuum gas oil (HVGO), and fluid catalytic cracking (FCC) feed hydrotreater diesel fraction when the ASTM D 1160 method is used. Understandably, the question arises whether it is possible to extract more diesel from the heavy oils. If one uses the ASTM D 1160 distillation data, the answer to this question could be no, but if the ASTM D 7169 is used, the answer could be yes. Another important question, which is also related to the evaluation of the feasibility to extract more diesel fraction from the heavy oil products, is which distillation data should be used in the process of the commercial distillation column performance simulation? [PERSON] [25], for example, recommends the use of the ASTM D 1160 standard to characterize heavy oils instead of the simulation distillation in process simulation. While, [PERSON] et al. [26; 27; 28] strongly recommend the employment of ASTM D 7169 when commercial distillation column operation simulation is concerned. A commercial distillation test at an operating distillation column separating mixtures containing heavy oils and simulation of its performance by a software process simulator may give an answer which laboratory distillation method ASTM D 7169 or ASTM D 1160 reports the correct value for the heavy oil diesel fraction content. For that reason, a commercial test at a FCC feed hydrotreater main fractionator was organized and performed in which the heavy oil streams were characterized by ASTM D 7169 and ASTM D 1160 methods.