High Temperature Simulated Distillation: ASTM D 7169
Robust hardware and automated software are critical to method ASTM D7169. The Shimadzu GC-2010, equipped with an advanced flow controller, has proven to be reproducible and effective, and Shimadzu distillation GC software has achieved automation by integrating calibration, integration, calculation, and report functions.
Zhuangzhi 'Max' Wang and C. Mark Taylor, Shimadzu Scientific Instruments, Inc.
Robust hardware and automated software are critical to method ASTM D7169. The Shimadzu GC-2010, equipped with an advanced flow controller, has proven to be reproducible and effective, and Shimadzu distillation GC software has achieved automation by integrating calibration, integration, calculation, and report functions.
Monitoring boiling point distribution characteristics is of vital importance to make the most efficient use of feedstock in the petro-refinery industry. Simulated distillation GC (DGC) methods have been widely practiced to replace conventional distillation methods such as D86 and D1160, which are time and labor consuming. In DGC methods, retention times are directly correlated to boiling points and detector responses are correlated to the hydrocarbon concentrations. A calibration curve can be generated by plotting boiling points of n-alkanes as a function of retention times and sliced peak intensities represent the sample amount distilled.
Method ASTM D 7169 extends the boiling point profile up to 720 °C (corresponding to the elution of n-C100), targeting at high boilers that do not easily elute out of a GC column. In this study, a Shimadzu GC-2010 based DGC system was employed to determine boiling point distribution of crude oil samples.
Sample Preparation
Standard samples: Prepared 0.5% Polywax 655 CS2 solution, then mixed with equal volume of D2887 SimDist standard. Both Polywax 655 and D2887 standards are from AccuStandard.
Sample pretreatment: 0.2 g sample were measured and dissolved in 20 mL CS2. Three replicate runs were conducted from different 1.5 mL vials.
Figure 1
Results
See Figures 1 and 2.
Figure 2
Conclusions
The robust GC-2010 hardware, integrated with Distillation GC software, has achieved fully automated DGC boiling points determination, in compliance with ASTM D7169.
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