A Comparative Evaluation of Nitrogen Compounds in Petroleum Distillates

Abstract

Although the concentration of nitrogen compounds in crude oil is relatively low, they can become more concentrated in petroleum distillates and poison the catalysts used in refining processes. They cause undesirable deposits, color formation and odor in products; they also contribute to air pollution and some are highly carcinogenic. The poisoned catalyst becomes deactivated for hydrodesulfurization and unable to remove sulfur from middle distillates. In order to understand the effect on catalytic processes, it is desirable to identify the nitrogen compounds in various petroleum distillates. This paper compares the nitrogen species profiles in different petroleum distillates using a nitrogen chemiluminescence detector. In addition, four different petroleum distillate samples from different refineries were analyzed to find the variation in their nitrogen profiles. The nitrogen compounds in petroleum distillate samples were identified as anilines, quinolines, indoles, and carbazoles and their alkyl derivatives. Quantitation was carried out against known reference standards. The quantitative data were compared to the total nitrogen content determined by elemental analysis.

Fluorescence of A100 MOF and Adsorption of Water, Indole, and Naphthalene on A100 by the Spectroscopic, Kinetic, and DFT Studies

“…We checked the origin of the fluorescence of A100 MOF by comparing the fluorescence spectra from A100 MOF and solutions of model compound BDCH 2 in water at different pH. Figure 3A shows the normalized fluorescence spectra at λ exc = 260 nm obtained from BDCH 2 in its anionic (BDC) 2 The spectra have nearly the same position of spectral maximum and shape that indicates that the fluorescence emission is not dependent on whether the COOH group is dissociated. These data are consistent with absorption spectra of BDCH 2 vs (BDC) 2− in solution ( Figure 2) that are also independent of the pH.…”

“…400−480 nm as observed with both λ exc = 260 ( Figure 4A) and 310 nm ( Figure 4B). On the other hand, a complete quenching of emission from the BDC linker in A100 occurs in the adsorption complex with indole (AlOH) 2 …”

Preparation of a Nitrogen Oil Compound Fraction by Modified Gel Silica Column Chromatography

“…These compounds are naturally present in oils, almost entirely in organic form, tending to concentrate heavier fractions in crude oil. Nitrogen compounds are classified as basic, having pyridine (quinoline, benzoquinoline), or nonbasic rings, such as pyrrolic (indolic, carbazolic, and benzocarbazolic) rings (Supporting Information Figure S1), and mixed polycyclic compounds containing S, N, O, and metals. , Although nitrogen compounds are present at low concentrations, less than 2 wt %, nitrogen values above 0.25 wt % are considered high, and the average value is around 0.1 wt % …”

Quantification of nitrogen compounds in diesel fuel samples by comprehensive two-dimensional gas chromatography coupled with quadrupole mass spectrometry

“…Nitrogen compounds (N‐compounds) naturally occur in petroleum samples and in their derivative products . The N‐compounds in diesel fuel, although present at low concentration levels (mg/L), are still a concern because they have various undesirable properties during its refining process and throughout its usage that affect the stability of the refined products.…”