Andre Hauser

Identification of biomarker compounds in selected Kuwait crude oils

Eighteen crude oils from Kuwait oil fields were analyzed by capillary GC/MS spectroscopy. Thirty-two biomarker compounds, 18 pentacyclic triterpanes and 14 steranes were identified and semi-quantitatively determined by selective ion monitoring (SIM) chromatography. The data obtained were used to calculate several biomarker indices. Depending on the oil source, the variation in the pentacyclic triterpanes distribution is more significant than the variation in the sterane distribution. The C29 norhopane and C30 hopanes were the dominating biomarkers in all the crude oils analyzed. The calculated biomarker indices indicated that the analyzed oils stem from medium mature oil reservoirs that have undergone biodegradation, to a certain extent.

Composition of high boiling petroleum distillates of Kuwait crude oils

Abstract Four crude oils of diverse API gravities were distilled on an 801 Autodest, Model 800 distillation unit to obtain vacuum gas-oil (VGO) distillates in the boiling range of 360–525°C. These distillates were separated into acids and bases by anion and cation exchange resins, and neutral nitrogenous compounds were removed by ferric chloride (FeCl3) on cellulose. Saturates were separated from aromatics by silica-alumina gel chromatography. Characterization of the crude oils and VGO distillates was carried out according to IP and ASTM methods. Nuclear magnetic resonance (NMR) spectroscopy was used successfully to calculate average molecular parameters and to elucidate an average molecular structure of the separated fractions.

An Investigation of the Deactivation Behavior of Industrial Mo/Al2O3 and Ni-Mo/Al2O3 Catalysts in Hydrotreating Kuwait Atmospheric Residue

Abstract The catalyst system for fixed-bed residue hydrotreating processes usually consists of different types of catalysts designed to promote hydrodemetallation (HDM), hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) reactions to desired levels. Overall catalyst life is determined by the performance of the individual catalysts in the different reactors. Therefore, information about the activity, stability, selectivity, and deactivation behavior of the individual catalyst is highly desirable to design improved catalysts that can prolong catalyst life, increase stream efficiency, and improve process economics. In the present work, residue hydrotreating experiments were conducted on two types of industrial hydrotreating catalysts, namely Mo/Al2O3 and Ni-Mo/Al2O3, that have been used as HDM and HDS catalysts, respectively, in an industrial ARDS process. The primary objective of the study was to compare the deactivation behavior of both types of catalyst. The characterization of the used catalysts by elemental analysis, surface area, pore volume, and pore size measurements along with TPO-MS, 13C NMR, and electron microprobe analysis showed significant differences in the nature of the coke and metal deposits on the two types of catalysts. The role of initial coking, the relative importance of the coke, and metal depositions on the deactivation of the two types of catalyst are discussed.

STUDIES ON DEPOSITS OF SPENT HYDRO-TREATING CATALYST: A STUDY BY COMBINED ANALYTICAL TECHNIQUES

ABSTRACT Carbonaceous and non-carbonaceous deposits on a Ni-Mo catalyst, stemming from atmospheric residue upgrading in an ARDS unit were subjected to a combination of analytical techniques, i.e. SF extraction, TGA/DTA/MS, DRIFT, l3C CP-MAS NMR, XRD and elemental analysis. Since the spectroscopic features of several components of the deposit interfere with each other a detailed deposit characterization was only achieved by stepwise removal of certain components by SFE deoiling and calcination. SF extraction stripped about 22 wt % of the carbonaceous deposit of the spent catalyst increasing the sp2/(sp3 + sp2) ratio of the NMR-visible carbon from 0 63 to 0.67. TGA revealed three separate temperature ramps for stepwise driving off of deposited material- first ramp, 30° C - 280° C, loss of oil and sulfur from metal sulfides; second ramp, 280° C - 450° C, loss of carbonaceous material like coke; third ramp, 500° C - 680° C, loss of metal sulfates. Further calcination up to 1000° C has no effect on the metal c...