There is a need for reliable and fast means of monitoring refining, conversion, and upgrading processes aiming to increase the yield of light distillates, and thus, reducing the oil barrel bottoms. By simultaneously utilizing the FID and mass selective detectors while splitting the column effluent in a controlled way, it is possible to obtain identical gas chromatograms and total ion chromatograms from a single run. This means that besides the intensity vs. time graphs, the intensity vs. mass and boiling point can also be obtained. As a result, physical and chemical characterization can be performed in a simple and rapid manner. Experimental results on middle, heavy distillates, and crude oil fractions show clearly the effect of upgrading processes on the chemical composition and yields of diesel, jet fuels, and high vacuum gasoil fractions. The methodology is fully compliant with ASTM D-2887, D-7213, D-6352, and D7169 for simulated distillation and the previously mentioned mass spectrometry standards. The group type analysis correlated satisfactorily with high-performance liquid chromatography data.

This work presents the carrying out of boiling-point distributions by simulated distillation with direct-column heating rather than oven-column heating. Column-heating rates of 300 degrees C/min are obtained yielding retention times of 73 s for n-tetratetracontane. The calibration curves of the retention time versus the boiling point, in the range of n-pentane to n-tetratetracontane, are identical to those obtained by slower oven-heating rates. The boiling-point distribution of the reference gas oil is compared with that obtained with column oven heating at rates of 15 to 40 degrees C/min. The results show boiling-point distribution values nearly the same (1-2 degrees F) as those obtained with oven column heating from the initial boiling point to 80% distilled off. Slightly higher differences are obtained (3-4 degrees F) for the 80% distillation to final boiling-point interval. Nonetheless, allowed consensus differences are never exceeded. Precision of the boiling-point distributions (expressed as standard deviations) are 0.1-0.3% for the data obtained in the direct column-heating mode.

Characterization of petroleum samples in terms of boiling point distributions is at the core of the oil business. In addition, knowledge of chemical properties like molecular weight (MW) and hydrocarbon group-type as well as class-type distributions are also important parameters for monitoring upgrading processes. This work studied the feasibility of using gas chromatography coupled to flame ionization and mass spectrometry detection (GC-FID-MS) for providing all the former mentioned parameters in a fast and simple simultaneous approach that requires less than 1 h for completion. Comparison with routine thin layer chromatography with flame ionization detection (TLC-FID) and standardized supercritical fluid chromatography (SFC) for hydrocarbon group and class-type analyses validated the approach and, furthermore, allowed one to highlight advantages or disadvantages for the compared techniques. Upgrading processes carried out with atmospheric and vacuum distillate feedstocks were monitored with the mentioned characterization tools. The application of these techniques was found suitable for analyzing petroleum distillates comprised within the C5−C60 carbon range. GC-FID-MS was found suitable for samples containing low amounts of polar hydrocarbons, in addition was determined capable to discriminate HC-class-types for complex samples arising from hydroprocessing, catalytic upgrading, and physically separated distillation cuts. On the other hand, SFC and TLC-FID yielded restricted applicability in the light or heavy distillation ends.