Investigation of nitrogen compound types in high-boiling petroleum distillates from Saudi Arabian crude oil
General Material Designation
[Thesis]
First Statement of Responsibility
M. A. Ali
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
King Fahd University of Petroleum and Minerals (Saudi Arabia)
Date of Publication, Distribution, etc.
1987
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
241
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
M.S.
Body granting the degree
King Fahd University of Petroleum and Minerals (Saudi Arabia)
Text preceding or following the note
1987
SUMMARY OR ABSTRACT
Text of Note
This study aims at the selective separation of acids, bases and neutral nitrogen compounds from high-boiling distillates (370-535C) of Arab Heavy and Arab Medium crude oils. Preliminary work was carried on all four Saudi Arabian crude oils and their distillates in the boiling range 370-535C (700-1000F). The distillates were prepared using atmospheric and vacuum distillation. The study has shown that the basicity, aromaticity, average molecular weights and degree of ring condensation in distillates increase with an increase in heteroatomic contents, carbon residues and viscosity of the material. Acids and bases were separated with anion and cation exchange resins respectively while the neutral nitrogen compounds were removed by complexation with ferric chloride supported on Attapulgus clay. These fractions were further separated into distinct nitrogen compound types namely pyridines, pyrroles and amides using high performance liquid chromatography on neutral alumina. A nonaqueous potentiometric titration method was developed to determine the basic and nonbasic nitrogen in the distillates and the separated fractions. Titration of distillates and HPLC fractions also led to the determination of strong and weak basic nitrogen. A chromatographic-Infrared method was used for the quantitative determination of major compound types. The results were compared with titration and total nitrogen data. Comparison of the results from the two methods has shown that these techniques can be employed for the determination of compound types in complex petroleum fractions. Characterization of nitrogen compound types was made on the basis of infrared and ultraviolet spectroscopy. Vapor pressure osmometry was used to determine the average molecular weights. Characterization of individual nitrogen compounds was accomplished using gas chromatograpy and gas chromatograpy-mass spectrometric analysis. Sixteen nitrogen compounds were positively identified by GC-MS analysis. These compounds represent three compound types which are pyridine, pyrrole and amide.