Identification and Reactivity of Nitrogen Molecular Species in Gas Oils

Abstract

Nitrogen molecular species in several gas oils were analyzed by gas chromatograph with an atomic emission detector (GC-AED) and mass spectrometer (GC-MS). Nitrogen species in gas oils were divided through acidic extraction into basic species (such as aniline, quinoline, benzoquinoline, and their derivatives) and nonbasic species (such as indole, carbazole, and their derivatives). To be mostly identified, their distribution depended on the cutting point and origins of gas oils. Denitrogenation reactivities of nitrogen species in gas oils were followed in the hydrotreating reactions at 340 °C under 5MPa of H2 to quantify by GC-AED their respective reactivities in GOs. The reactivities orders and reactivity dependence on their chemical structures and matrix compositions are discussed on molecular bases. The reactivity order was found as indole > methylated aniline > methylated indole > quinoline > benzoquinoline > methylated benzoquinoline > carbazole > methylated carbazoles. The number and position of methyl groups were very influential on the reactivities of carbazole derivatives. Methyl groups neighboring the N atom inhibited remarkably the HDN reactions. Comparison of the reactivities of the same species in the GOs must be discussed by taking account of all components and products in the respective oil.

Adsorption Thermodynamics of Sulfur- and Nitrogen-containing Molecules on NiMoS: A DFT Study

“…In deep hydrodesulfurization (HDS), inhibitory effects of basic nitrogen-containing compounds on HDS conversion are so severe that it becomes the dominant factor that prevents the complete HDS of 4,6-dimethyldibenzothiophene [9]. It has also been reported that basic and non-basic nitrogen compounds have different hydrodenitrogenation (HDN) reactivities, and the differences in HDN reactivity are partly due to their different adorptivities on catalyst active sites [10,11]. Detailed adsorption thermodynamic data of hydrotreating-relevant molecules on hydrotreating catalyst active sites can provide additional fundamental insight towards understanding competitive adsorption and inhibitory effects of the sulfur-and nitrogen-containing molecules in the hydrotreating processes.…”

Kinetic Modeling of Vacuum Gas Oil Hydrotreatment using a Molecular Reconstruction Approach

“…Therefore, kinetic modeling of hydrotreating is essential to understand and predict the performances of hydrodearomatization (HDA), hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) reactions. Several literature works have studied the behavior, mechanisms and kinetics of hydrotreating of industrial gasolines, diesel cuts [27][28][29][30][31][32][33][34][35][36] as well as Vacuum Gas Oils [36][37][38]. However, concerning VGOs, no detailed kinetic model has been reported in literature.…”

Application of Microorganisms to the Processing and Upgrading of Crude Oil and Fractions

“…Nitrogen heterocycles are classified in basic compounds which are related to quinoline and usually comprise 25-30% (w/w) of all nitrogen heterocycles, while nonbasic compounds are alkylated derivatives of carbazole and comprise 70-75% of nitrogen heterocycles (Mushrush et al, 1999;Laredo et al, 2002). Another problem associated to nitrogen compounds is that basic nitrogen compounds are known to inactivate HDS catalysts (Shin et al, 2000;Zeuthen et al, 2001). Nonbasic compounds can be converted to basic ones during the refining/catalytic cracking process, and thus, they also are potential inhibitors of HDS processes (Choi et al, 2004;Laredo et al, 2003Laredo et al, , 2004.…”