Simultaneous Determination of Boiling Range Distribution of Hydrocarbon, Sulfur, and Nitrogen in Petroleum Crude Oil by Gas Chromatography with Flame Ionization and Chemiluminescence Detections Ramachandra Chakravarthy, †,‡ Ganesh N. Naik, † Anilkumar Savalia, † Jagdish Kedia, † Chandra Saravanan, † Asit Kumar Das, † Unnikrishnan Sreedharan, † and Kalagouda B. Gudasi* ,‡ † Reliance Industries Limited, Reliance Corporate Park, Research & Development Centre, Thane-Belapur Road, Ghansoli-400701, Navi Mumbai, Maharashtra, India ‡ Department of Chemistry, Karnatak University, Pavate Nagar, Dharwad-580003, Karnataka, India * S Supporting Information 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. 1. INTRODUCTION The petroleum industry is the lifeblood of the global economy. 1,2 As the world struggles to emerge from global recession and financial crises, countries are looking for solutions to improve energy sources and their performance improve- ment. Globally, more than 600 refineries are currently in operation, producing a minimum of 100 million barrels of refined products per day using a variety of crude oils. 3,4 Each refinery has a unique physical configuration, operating conditions, and economics. 4 In the basic refinery process, crude oil is heated up to about 600 °C by passing superheated steam of high pressure at the bottom of the vertical distillation column, 5-7 from which various petroleum fractions such as petroleum gas, naphtha, kerosene, diesel, lubricant, gas oil, and solid petroleum coke get separated depending upon their boiling points. Analytical techniques play a key role in the characterization of each fraction in order to troubleshoot and optimize the refinery processes. 8-12 Each crude oil is a unique and complex mixture of several components, mainly hydrocarbons and a significant quantity of hetero elements such as sulfur, nitrogen, oxygen, and certain metals like nickel, vanadium, arsenic, mercury, sodium, magnesium, zinc, et cetera. 13,14 Sulfur and nitrogen molecules pose signi ficant challenges in a refinery. Strict sulfur specifications in gasoline and diesel fuels determine how crude oils get blended and processed. Difficult sulfur, such as the sterically hindered thiophenic type of molecules, pose considerable challenges in hydrotreating and hydrocracking processes and are poisons to certain catalytic processes. 15,16 Sulfur also plays a key role in sulfidic corrosion of refinery equipment and pipelines. 17,18 On the other hand, nitrogen is also a serious poison to catalytic cracking processes. Stringent regulatory requirements for emission of sulfur oxides (SOx) and nitrogen oxides (NOx) 19,20 also limit S and N content in petroleum products such as gasoline, jet fuel, diesel, et cetera. Received: December 13, 2016 Revised: January 31, 2017 Published: February 1, 2017 Article pubs.acs.org/EF © XXXX American Chemical Society A DOI: 10.1021/acs.energyfuels.6b03306 Energy Fuels XXXX, XXX, XXX-XXX