Simultaneous Determination of Boiling Range Distribution of Hydrocarbon, Sulfur, and Nitrogen in Petroleum Crude Oil by Gas Chromatography with Flame Ionization and Chemiluminescence Detections

Abstract

We present a quick and efficient gas chromatographic method to simultaneously determine the boiling range distribution of hydrocarbon (C), sulfur (S), and nitrogen (N) in crude oils by a high temperature–CNS simulated distillation (HT-CNS SimDis) analyzer. The analyzer is a gas chromatograph equipped with flame ionization (FID) and sulfur and nitrogen chemiluminescence (SCD and NCD) detectors with simulated distillation features. The hydrocarbon yield profile of crude oil obtained by FID response was applied to calculate S and N content in various isolated fractions such as naphtha, kerosene, diesel, and vacuum gas oil. This method was used to analyze 10 different crude oils of variable composition. A fraction of crude oil that boils above the atmospheric equivalent temperature (AET) of 700 °C does not elute fully and forms a coke inside the chromatographic column. As a result, it is not possible to quantify total sulfur and total nitrogen content in the high-boiling vacuum residue (VR) fraction (565 °C and above) of crude oil by this method. However, we have addressed this issue by calculating sulfur in the VR fraction as a difference between total sulfur in crude oil (using X-ray fluorescence or combustion methods) and sulfur in the rest of the fractions (using HT-CNS SimDis). A similar technique was employed to determine nitrogen in the VR fraction of crude oil. The gas oil reference standard with known boiling range distribution was used to check the system suitability and generate the response factor for the calculation of hydrocarbon yield, and VGO NS Reference (internal nitrogen/sulfur QC standard) was used as a calibration standard for sulfur and nitrogen quantification. Currently, there is no single method available for the simultaneous determination of C, S, and N present in crude oil. This method produces detailed temperature distribution of S and N in a crude oil sample that cannot be obtained by either total sulfur and total nitrogen analysis or analysis of sulfur and nitrogen in discrete distillation cuts. As a result, this technique is extremely valuable to the refining industry for the valuation of crude oil, plant troubleshooting, and optimization of refinery processes.

Sulfur and Total Carboxylic Acid Number Determination in Vacuum Gas Oil by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

“…The total sulfur content of all VGO samples have been performed using HT-CNS SimDis analyzer. , Approximately 100–200 mg of VGO samples were weighed in a glass vial, and 5 g of HPLC grade cyclohexane was added to the sample to dissolve the sample. The weight of the sample and solvent were accurately measured to the nearest 0.1 mg. A homogeneous solution of the sample was then transferred to a 2 mL GC vial and the contents sealed with an aluminum crimp cap.…”

“…The calibration plot for total sulfur content was drawn using “VGO NS reference” in-house material with a known quantity of sulfur content. The values of sulfur content obtained by this method for both VGO samples and the VGO NS reference standard were validated with the reference standard methods. , Data analysis was done by using SimDis software provided by PAC, Netherlands. All of the sample analysis was carried out in triplicate, and the average value of sulfur content obtained was considered for ATR-FTIR chemometrics model development.…”

“…Currently, the standard reference methods for the determination of total sulfur content in petroleum heavy fractions are X-ray and ultraviolet fluorescence spectroscopy (ASTM D-4294 and ASTM D-5453). , Several gas-chromatography-based methods are used in the literature for sulfur measurement in refinery fractions. Recent advances in sulfur determination involves the use of CNS-Simulated distillation instrument. , These methods are reliable but needs laborious sample preparation and cumbersome calibration procedures. CNS-simulated distillation cannot be made portable and is currently not available as online technology.…”

“…Recent advances in sulfur determination involves the use of CNS-Simulated distillation instrument. 69,70 These methods are reliable but needs laborious sample preparation and cumbersome calibration procedures. CNSsimulated distillation cannot be made portable and is currently not available as online technology.…”

Simulation of Reaction Pathways of Sulfur Compounds and Product Properties Based on the Molecular-Level Hydrotreating Reaction Model

“…The first step in the establishment of the hydrotreating model was to apply the SOL method to achieve a digital representation of the molecular composition of the diesel feeds. Therefore, this study applied comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry to obtain the molecular information in the diesel feeds , and used the gas chromatography with sulfur chemiluminescence detector to analyze the structures and content of sulfur-containing molecules. , …”