Petroleum Residues Research Articles

Hydrogen Transfer of Petroleum Residue Subfractions During Thermal Processing under Hydrogen

AbstractAnthracene (ANT) was applied as the accepting probe to evaluate the hydrogen transfer ability of a Venezuela petroleum residue and its subfractions (i.e., saturates, aromatics, resins, and asphaltenes) under different atmospheres and reaction conditions. The hydrogen donating ability (HDA) of H2, HDA of the fractions, and synergism between fractions and H2 were analyzed. The results show that the temperature, initial hydrogen pressure, and time have a positive effect on the HDA of hydrogen. The HDA of all of the subfractions increases clearly with increasing temperature, both under nitrogen and hydrogen, before an equilibrium is achieved, and the HDA determined under hydrogen is higher than that measured under nitrogen. The saturates (Sa) and aromatics (Ar) showed a positive synergism with hydrogen, whereas the resins (Re) and asphaltenes (Asp) showed a negative one according to the calculated synergism. The summation HDA determined under nitrogen was significantly lower than the original HDA of the Venezuela petroleum residue, whereas the trend for hydrogen was the opposite.

Association Model for Nickel and Vanadium with Asphaltene during Solvent Deasphalting

Solvent deasphalting is a highly efficient process for removing asphaltene and metals from the petroleum residue; however, there are rare modeling studies about the interaction between metals and asphaltene. This work establishes the association models of metals (Ni and V) with asphaltene during solvent deasphalting. The models reveal that the distribution factors of metals are related to the solvent density, association enthalpy, and temperature. The association energy of metal–asphaltene is higher than that of metal–resin. The distribution factor of metals with asphaltene is lower than that without asphaltene. The tuned model could well-predict the distribution factors for both Ni and V. The models provide the thermodynamics and theoretical guide for removing the metals from the heavy oil during solvent deasphalting.

Quantitative Vacuum Distillation of Crude Oils to Give Residues Amenable to the Asphaltene Determinator Coupled with Saturates, Aromatics, and Resins Separation Characterization

The automated Asphaltene Determinator coupled with saturates, aromatics, and resins (SAR–AD) separation is a powerful characterization tool initially designed for the rapid and repeatable analysis of asphalt bitumen and petroleum residua. By virtue of the evaporative light scattering detector (ELSD) and the fact that saturates and a portion of aromatics do not contain chromophores, making them undetectable in the 500 or 700 nm detectors, the complete quantification of petroleum fractions by this method is somewhat restricted to samples that do not contain a significant amount of volatiles. Crude oils can contain more than 70% of volatile material, which is not detected by the ELSD. To overcome the SAR–AD volatile limitation, a quantitative vacuum distillation method was developed to capture the volatiles and produce unaltered residua that does not lose volatiles in the ELSD. To complete the characterization, the volatiles are analyzed for their saturate, aromatic, and reactive olefin contents by proton nu...

Successive co-operation of supercritical water and silica-supported iron oxide nanoparticles in upgrading of heavy petroleum residue: Suppression of coke deposition over catalyst

The chemical effect of supercritical water (SC-H2O) on catalytic cracking of heavy petroleum residue was investigated over silica-supported hematite iron oxide nanoparticles, and the stability of catalyst against coke formation was approved by numerous analyses after sequence of reactions. First, the catalysts of process, with different active phase (α-Fe2O3) to support (SiO2) weight ratio, were prepared successfully via supercritical water impregnation approach. The performance of the α-Fe2O3–SiO2 was then considered on transformation of vacuum residue (VR) to lighter fuels in supercritical water medium. Comparing the results with non-catalytic degradation, i.e., SC-H2O pyrolysis, improvement of heavy oil conversion towards lighter fragments (maltene) was attained. The higher amount of asphaltene transformation as well as suppression in coke formation over/in catalyst could be attributed to larger portion of cracking occurred mainly in catalyst surface and pore volume (PV), whereas the cracking based on pyrolysis was accomplished free-radically in bulk volume (BV). In catalytic reaction, a consecutive cyclic reaction is taking place as; oxidative cracking of asphaltene over catalyst (with converting Fe3+→Fe2+) followed by in-situ hydrogenation of cracked fragments via in-situ hydrogen resulted from dissociation of water (with converting Fe2+→Fe3+). Moreover, SC-H2O reforming of hydrocarbons (CmHn) and conversion of those containing oxygen-containing groups, e.g., ethers, esters, carboxyls, carbonyls, to CO as well as related water–gas shift reaction (CO+H2O→H2+CO2) would facilitate over catalyst by which higher amount of asphaltene conversion and maltene yield were attained.

An Experimental Study of a Pilot Plant Deasphalting Process in CO2 Supercritical

The authors aimed to study the deasphalting process on laboratory scale through the design and development of a supercritical extraction experimental unit. The experimental unity used in tests is composed by a pump, an extractor with useful volume of 3 L and one separator vessel. Extractions in supercritical conditions were carried out using petroleum residue (vacuum and atmospheric residuum) as feedstock and dioxide carbon (CO2) as solvent. Temperature and pressure were manipulated in order to maintain the solvent in the required conditions, thus facilitating the extraction process and avoiding sharp changes in the system. In supercritical conditions, the products in the deasphalted oil stream present adequate characteristics for the production of lubricant oils and those in the asphalt residue stream present an elevated concentration of asphalt molecules.

Experimental study of the form of “hot” steel particles on the ignition characteristics of liquid fuels

The results of an experimental study of laws governing the ignition of liquid propellants (kerosene, diesel fuel and petroleum residue) by the single spherical steel particle heated to high temperatures are presented. Is carried out the comparison of the ignition delay times of the investigated flammable substances by the particles in the sphere and disk forms. It is established that the particle shape does not exert a substantial influence on the ignition process characteristics.

Modification of optical properties of seawater exposed to oil contaminants based on excitation-emission spectra

The optical behaviour of seawater exposed to a residual amount of oil pollution is presented and a comparison of the fluorescence spectra of oil dissolved in both n-hexane and seawater is discussed based on excitation-emission spectra. Crude oil extracted from the southern part of the Baltic Sea was used to characterise petroleum properties after contact with seawater. The wavelength-independent fluorescence maximum for natural seawater and seawater artificially polluted with oil were determined. Moreover, the specific excitation-emission peaks for natural seawater and polluted water were analysed to identify the natural organic matter composition. It was found that fluorescence spectra identification is a promising method to detect even an extremely low concentration of petroleum residues directly in the seawater. In addition, alien substances disturbing the fluorescence signatures of natural organic substances in a marine environment is also discussed.

Effect of the textural parameters of the carrier and the preparation procedure of the supported Ni-Mo/Sibunit catalysts on their catalytic activity

The results of studies on the preparation of Ni-Mo sulfide catalysts based on a carbon-carbon composite material of the Sibunit type for the hydrocracking of heavy petroleum residue are reported. The effects of the support texture and the conditions of catalyst preparation on catalytic activity in the model reactions of 1-methylnaphthalene and dibenzothiophene conversion were demonstrated.

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

The aim of this work was to investigate vacuum residues hydroconversion using acid-modified catalysts. To achieve this goal, silicon was incorporated by a grafting procedure. The catalysts with different silicon amounts in the support or hydrogenating actives phases were evaluated performing hydrotreatment of a Safaniya vacuum residue at 370°C. A multi-techniques set of analyses was used, in order to characterize both the sulphided active phase and acidity. It can be concluded from this study that acidity is beneficial for conversion of asphaltenes but the hydrogenation active phase does not seem to be the main way to improve the transformation. The proposed mechanism is the following: with short reaction time, acidity promotes cracking of naphthenic and alkyl units but hydrogenation is not completed. Then, with longer reaction times, asphaltenes reveal a loss of aromatic rings which demonstrates that the hydrogenation pathway is enhanced and a significant loss of molecular weight is observed. This new way of transformation opens the way to a complete change of reactivity over the whole HDT processes. If used as a pretreatment of petroleum residues, this type of catalyst could drastically improve the conversion yield of heavy feeds in order to develop sustainable refining processes.

Synergism of Hydrogen and Oil Composition in Noncatalytic Upgrading of Petroleum Residues

Synergism of hydrogen and composition of oils in noncatalytic upgrading of different petroleum residues were analyzed. Residues were upgraded under temperature of 400°C and initial pressure of 4 MPa for 20 min in the presence of hydrogen or nitrogen, respectively. In addition, anthracene was used as chemical probe to quantify the hydrogen-donating ability of the three feedstocks and the contribution of hydrogen gas. Results show that hydrogen has better synergism with the residue that contains more naphthenic aromatic structure, heteroatom, and metals. Moreover, hydrogen activation possibilities limit the effect of the hydrogen solubility of the oils on upgrading.

Simulation of Petroleum Residue Hydroconversion in a Continuous Pilot Unit Using Batch Reactor Experiments and a Cold Mock-Up

The kinetics of atmospheric petroleum residue hydroconversion with a dispersed catalyst was studied. A methodology has been developed in order to transpose the chemical kinetics (reaction network, stoichiometry, and kinetic constants) obtained with a batch reactor by Nguyen et al. to a continuous reactor [Nguyen, T. S.; Tayakout-Fayolle, M.; Ropars, M.; Geantet, C. Chem. Eng. Sci. 2013, 94, 214]. Their five-lump kinetic model takes into account vapor–liquid mass transfer, vapor–liquid equilibriums, and hydrogen consumption. Consequently, hydrodynamics and vapor–liquid mass transfer of the micropilot unit’s reactor were studied in a cold mock-up by tracer experiments. The same thermodynamic model given by Nguyen et al. was used, and the flash calculations were performed using ProSimPlus software. Experimental data were obtained in the micropilot unit at 420, 430, and 440 °C with a dispersed catalyst for residence times of 1 and 2 h. The catalyst precursor, an oil-soluble molybdenum naphthenate, was added to obtain a molybdenum concentration of 600 wt ppm in the feedstock. The total pressure was 12 MPa with a hydrogen-to-feed ratio of 500 N m3/m3. The methodology was validated by comparing the model’s output with the experimental results.

An Experimental Study of a Pilot Plant Deasphalting Process in Subcritical and Supercritical Conditions

The authors aimed to study the deasphalting process on laboratory scale through the design and development of a supercritical extraction experimental unit. Extractions in subcritical and supercritical conditions were carried out using petroleum residue as feedstock and propane as solvent. Temperature and pressure were manipulated in order to maintain the solvent in the required conditions, thus facilitating the extraction process and avoiding sharp changes in the system. In supercritical conditions, the products in the deasphalted oil stream present adequate characteristics for the production of lubricant oils and those in the asphalt residue stream present an elevated concentration of asphalt molecules.

Continuum approximation of large reaction mixtures in reactors with backmixing

The growing need to produce ultraclean fuels from hydrocarbon mixtures such as petroleum fractions and residues has put increasing pressure on refiners to achieve deep conversions. It is imperative to be able to predict the behavior of such mixtures at high conversions as functions of their properties and reactor type. To this end, treating the reaction mixture as a continuum greatly simplifies the analysis and modeling of the conversion process. However, the continuum approximation can become invalid at very high conversions. Previously, we examined the validity of the approximation for various reactions in plug flow reactors. The validity conditions for first‐order reaction mixtures in reactors with different mixing intensities are developed. In general, backmixing widens the range of validity. In certain cases, the continuum approximation is valid at arbitrarily high conversions. © 2014 American Institute of Chemical Engineers AIChE J, 61: 159–165, 2015

Occurrence of polycyclic aromatic hydrocarbons in the Soan River, Pakistan: Insights into distribution, composition, sources and ecological risk assessment

Present study investigates the occurrence, distribution and sources of ∑17 polycyclic aromatic hydrocarbons (PAHs) in the surface water of Soan River, Pakistan. The concentrations of total PAHs ranged from 61 to 207ng/l. Low molecular weight (LMW) PAHs were recorded higher in concentrations (64.7 percent) as compared to high molecular weight (HMW) PAHs (35.6 percent). Principal component analysis (PCA) revealed domestic and industrial wastewater discharge, vehicular exhaust, petroleum residues and biomass combustion as the main sources for PAHs contamination. Using the USEPA toxic equivalency factor (TEF) approach: Benzo(a)Pyrene and Dibenzo(a,h)Anthracene contributed highly carcinogenic exposure equivalent. The surface water of the Soan River is found to be slightly polluted with PAHs thereby posing health risks to aquatic bodies.

Recovery and Characterization of Petroleum Residues Through the Molecular Distillation Process

Molecular distillation process is an efficient way to separate complex residues to obtain improvement and a more complete characterization of crude oils. It presents advantages such as to generate distillation products that can be experimentally characterized, and the operation conditions of this process generate distillate cuts with an atmospheric equivalent boiling point (AEBP) above 650°C without risks of thermal degradation. The aim of this work is to carry out the separation of two vacuum residues (VR) within the process temperature range from 550 to 670°C, using the Brazilian Molecular Distillation equipment. As a result, five distillate cuts and five residues from molecular distillation processing were generated. The molecular distillation (MD) technique provided a gain in distillate yield of about 10% over the conventional methods. The efficiency of the technique was verified through the vapor pressure osmometry experiments and the extension of true boiling point (TBP) curves of petroleum. The extended TBP curves by the molecular distillation process demonstrated that this alternative method is appropriate to extend the TBP curves to temperatures above those of the conventional methods.

Pitch based carbon fibers for automotive body and electrodes

Pitch is an attractive raw material for carbon fiber precursors due to its low cost stemming from its availability as a residue of coking and petroleum processes. Ford Motor Company reported a carbon fiber target price of $11.0/kg by using a fast cycle-time manufacturing method with carbon fiber in an inexpensive format, allowing for an average retail price of gasoline of $3.58/gallon. They also recommended the use of carbon fiber with strength of 1700 MPa, modulus of 170 GPa, and 1.5% elongation. This study introduced a ca. 5.5 μm carbon fiber with 2000 MPa tensile strength obtained from a precursor through simple distillation of petroleum residue. Petroleum pitch based carbon nanofibers prepared via electrospinning were characterized and potential applications were introduced on the basis of their large specific surface area and relatively high electrical conductivity.

Oil Pollution in the Marine Environment II: Fates and Effects of Oil Spills

Part I of this three-part set of articles focused on the various types and amounts of oil inputs to the marine environment. The complexity of the mixture of chemicals making up crude oils, fuel oil...

Characterization of a continuous micro-scale pilot unit for petroleum residue hydroconversion with dispersed catalysts: Hydrodynamics and performances in once-through and recycling mode

Abstract A continuous micro-pilot unit has been designed to convert petroleum residues with dispersed catalysts. Once-through and recycling modes can be operated. Several operating conditions (residence times and temperatures) have been investigated using the molybdenum naphthenate as catalyst precursor (600 ppm). The micro-pilot hydrodynamics has been characterized via a cold mockup by Residence Time Distribution. Whatever the mode used, the conversion, product yields and average molecular weights depends only on residence time and temperature.

Sources of polycyclic aromatic hydrocarbons in PM2.5 over the East China Sea, a downwind domain of East Asian continental outflow

A receptor site in the East China Sea (ECS), ∼66 km off the shore of Shanghai, was used to investigate the seasonally atmospheric transport of land-based PAHs. Positive matrix factorization (PMF) modeling and back trajectories were performed to apportion the sources of the 16 USEPA priority PAHs (16 PAHs). In the process, three episodes were observed in all seasons except summer. These episodes provided additional insight to the transport mechanisms of these air pollutants in this most developed region of China. The average concentrations (in ng/m3) of PAHs in PM2.5 in fall, winter, spring and summer were 5.26 ± 5.36, 10.41 ± 8.58, 3.93 ± 2.31 and 0.97 ± 0.25, respectively, and with an annual average of 5.24 ± 5.81. Low molecular weight (LMW) PAHs (i.e., 2 ∼ 3-ring) was a dominant contributor for the 16 PAHs in PM2.5 over the ECS (36.2%), especially in summer (55.6%). The source apportionment by PMF analysis indicated that, based on yearly average, vehicular emission (27.0%) and coal combustion (24.5%) were the two major sources of PAHs, followed by biomass burning (16.5%), petroleum residue (16.3%) and air–surface exchange (15.7%). The highest source contributor for PAHs in fall and winter was coal combustion (30.5%) and vehicular emission (34.5%), respectively; while in spring and summer, the air–surface exchange contributed the most (27.1% and 59.5%, respectively). The specific composition patterns of 16 PAHs and PMF modeling results manifested that the air–sea exchange could be a potential source for the LMW PAHs in PM2.5 over the ECS, especially in warm season.

Characterization of the BP petroleum residuals in the sediment of the Salt Marshes in the Northern Gulf of Mexico by Fourier Transform Ion Cyclotron Resonance mass spectrometry

Of the estimated 5 million barrels of crude oil released into the Gulf of Mexico from the BP Deepwater Horizon event, a fraction heavily oiled Louisiana's coastal salt marshes. Oil inputs may significantly alter the abundance, structure and diversity of the microbial communities inhabited in the sediments, and subsequently affect essential microbial services. In this study, detailed analysis was conducted to investigate the possible impact of petroleum residuals on soil microbial communities of salt marsh in northern Barataria Bay of the Gulf of Mexico after the oil spill. Sediment samples from heavily, moderately, non-oiled sites were collected after 7 months, 16 months and 29 months of the spill and Total Petroleum Hydrocarbons (TPH) were measured. Since traditional gas chromatography (GC) analysis cannot identify heavy fractions of the oil containments, we incorporated ultrahigh resolving power Fourier Transform Ion Cyclotron Resonance mass spectrometry (FT-ICR-MS) to address the compositional complexity of high molecular weight, nonvolatile petroleum fractions of the oil containments that are not readily degraded by the indigenous microbial community. The petrogentic material was extracted with methylene chloride followed by positive and negative electrospray (ESI) FT-ICR-MS characterization. These data can be correlated with the analysis of the diversity and structure of the microbial community to elucidate how the oil contamination perturbed the microbial community and how the microbes responded to the perturbation. Mass spectrometry analysis of these samples display a 1.5 to 2.5 fold increase in the molecular complexity, particularly oxygen compounds relative to the original Macondo well oil and ketone species were abundantly present in the oiled sediment extracts. The comprehensive analysis on the petroleum residues will help us better understand the fate of oil released into the environment and the long-term impact of BP oil spill.