Vacuum Distillation Of Crude Oil Research Articles

Molecular Characterization of Aged Bitumen with Selective and Nonselective Ionization Methods by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. 1. Multiple Pressure Aging Vessel Aging Series

Bitumen is a very complex mixture corresponding to the residue from the vacuum distillation of crude oil. The complexity of such a mixture can be defined by its composition, with several thousand molecules that may contain heteroelements such as sulfur, nitrogen, and oxygen. Almost all bitumen production is used as a binder to produce asphalt pavements. Additional additives or physicochemical treatments can be used to improve the properties and lifetime of this binder. Asphalt pavements are subject to oxidative aging over the years, which leads to deterioration of the physical properties and reduces the performance and durability of the product. To have a better understanding of such mechanisms, artificial techniques can be used to simulate oxidative aging of bitumen. The most-used technique is the pressure aging vessel (PAV) which simulates the long-term aging of bitumens. To characterize oxidative aging at the molecular level, instruments such as Fourier transform ion cyclotron resonance (FTICR) are required. The ultrahigh resolution of this analyzer allows the unambiguous attribution of molecular formulas to each signal. Electrospray ionization (ESI) source was used to selectively ionize acid molecules, while atmospheric pressure photoionization (APPI) source was used to have a nonselective ionization of low-polarity molecules from bitumen. Analyses were carried out on four different PAV aging times (PAV-0h, 25h, 72h, and 96h) to characterize the aging kinetics from a bitumen sample. ESI results allowed the revealing of significant differences from the heteroatom class and family distributions starting from PAV-72h. It was defined by a general decrease of nonoxygenated families (Nx and NxSy) and by an increase of oxygenated families (Oz, NxOz, OzSy, and NxOzSy). The van Krevelen plot evidenced that aging markers correspond to low double bond equivalent (DBE) molecules. The occurrence of aldehydes and fatty acids (DBE 1) with aging in the CHOz family was characterized with DBE versus carbon number plots. Aging markers from OzSy were also characterized with occurrence of benzothiophenic (O2S1) and sulfonic acids (O3S1). Logically, less meaningful results were obtained with APPI. However, this nonselective source allowed the ionization of thiophenes, furans, cycloalkanes, and polycyclic aromatic hydrocarbons that were not observed in ESI measurements. Homogenic decreases in the distribution of nonoxygenated compound classes (HC, S1, S2, and N1) were observed. Concerning the oxygenated molecules, an expansion of the distribution was observed, but without the occurrence of specific aging markers. Oxidation seemed to be favored on linear and naphthenic molecules and not on the highly aromatic ones.

The New Test Procedure for Group-Type Composition of Base Oils of Lubricating Oils, Especially Emitted into the Environment

Mineral base oil, a product of multistep fine refining of the relevant fractions from vacuum distillation of crude oil, is a main component of so-called mineral lubricating oils containing aliphatic and alicyclic substituted aromatic hydrocarbons, i.e., derivatives of benzene and biphenyl. Mineral lubricating oil is composed mostly of mineral base oil and a low amount of enriching additives, most often products of advanced organic chemical technology. The application of mineral lubricating oils in open cutting systems has a very negative impact on environment and on the operator’s health. This work presents a simple, cheap and fast methodology allows identification of the group-type composition of base oil in lubricating oil and to estimate the content or total absence of base oil of mineral and vegetable origin in lubricating oil. The first step of the test is an in-situ screening for fluorescence of petroleum fraction under the 365 nm light. The next is the performance of infrared spectra with Fourier transformation (FT-MIR) to identify and estimate the content of vegetable oil and its derivatives and the performance of UV-Vis spectra to identify and determine the content of aromatic hydrocarbons, as well as dyes present in the lubricating oil. The last stage is normal phase thin layer chromatography (NP-TLC) using different visualization methods to evaluate the group-type composition of lubricating oil. Effectivity of the developed procedure has been confirmed during control of group-type composition evaluation of lubricating oils in cutting systems. The procedure can be also applied with respect to different oil matrices.

Comparison of Silica and Cellulose Stationary Phases to Analyze Bitumen by High-Performance Thin-Layer Chromatography Coupled to Laser Desorption Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Bitumen is a complex mixture corresponding to the residue of the vacuum distillation of crude oil. It can be separated on the basis of polarity and solubility with saturates, aromatics, resins, and...

The selective determination of potentially carcinogenic polycyclic aromatic compounds in lubricant base oils by the DMSO extraction method IP346 and its correlation to mouse skin painting carcinogenicity assays

Mineral oils are produced by vacuum distillation of crude oil at temperatures from ∼300 °C to ∼600 °C. Subsequent refining processes to eliminate the carcinogenic potential of mineral oils (by extraction and/or hydrotreatment) are based on the principle of removing substances associated with carcinogenic activity; i.e. PAC (polycyclic aromatic compounds), which include PAH and N or S heterocycles. Traditionally, the carcinogenic potential of the refined product was tested in the mouse skin painting assay. This bioassay is considered the gold standard for petroleum derived products since it uses the most sensitive species and route of exposure, and because mice and humans develop the same type of skin tumors it is a relevant model to assess the carcinogenic potential of mineral oils.Mouse skin painting studies have also been important in distinguishing two types of aromatic compounds found in mineral oil. The first type includes the 3–7 ring PAC associated with potential carcinogenic effects found in the 340–535 °C boiling range, which are removed by refinement. The second type includes highly alkylated aromatic compounds (predominantly 1–2 rings) which are not bioactivated and non-carcinogenic, which are typical of a refined oil.Because mouse skin painting studies are time consuming, a DMSO based method was developed that is capable to distinguish these two types of aromatics. Although this industry method, known as the IP346, has been applied for more than 30 years, the background experimental data underlying its development has not yet been published.This paper presents and discusses the chemical and biological features of mineral oil PAC structures assessed by IP346, especially the crucial role of the DMSO extraction step which allows to discriminate between the two types of aromatics. The DMSO selectivity towards the toxicological relevant PAC is discussed by comparing the composition of the DMSO extract of a distillate aromatic extract and mineral oils of varying viscosities and refining conditions. PAC which have >3 rings (naked or partially alkylated) are preferentially encompassed by the DMSO extract, whereas those PAC which have relatively long alkyl side chains are not. Thus, according to the IP346, refined oils will have lower levels of DMSO extractable material compared to less refined oils.DMSO selectivity towards the potentially carcinogenic >3 ring PAC makes the IP346 method therefore highly correlated to the outcome of mouse skin painting studies, using a pass/fail dichotomy. The accuracy, including the false negative results of the IP346 in the prediction of mineral oil carcinogenicity is discussed.The DMSO based IP346 is thus a simple but clear reflection of refinement efficacy. It links manufacturing conditions to carcinogenic potential of an oil, supported by solid physical-chemical and toxicological associations. In Europe it is the only legally binding method to assess, classify and label lubricating base oils and inherently more reliable for hazard assessment than the determination of an arbitrary selection of PAH.

Failure analysis of steam jet pump at top of crude oil vacuum distillation tower

The steam jet pump made by SAF 2205 duplex stainless steel (DSS) provides vacuum for vacuum distillation tower to improve the distillation efficiency of crude oil. The pump suffers from severe local wall thinning during service, especially at diffuser section. Failure analysis of the pump is carried out using traditional characterization techniques and computational fluid dynamics (CFD) simulation. The results show that the pump suffer from not only the electrochemical corrosion of acidic droplets forming in HCl-H2S-H2O environment, but also the mechanical erosion by high speed flow with a large value of wall shear stress. A vicious erosion-corrosion circle built by electrochemical corrosion together with mechanical erosion leads to severe damage at the diffuser section of steam jet pump.

Fouling Management of Thermal Cracking Units

ABSTRACTVisbreakers and other thermal cracking units are thermal process units in crude oil refineries that upgrade heavy petroleum, usually residual oils produced from atmospheric or vacuum distillation of crude oil. The associated process streams of these units consist of heavy hydrocarbons with very high viscosities and impurities, resulting in fouling of the heat exchangers used to cool or heat these streams. This paper presents a practical fouling analysis for thermal cracking units in a refinery in Germany. Fouling management at this refinery was initiated as part of the refinery energy-saving program. Following similar analysis of the refinery's crude preheat trains, heat exchanger networks associated in the thermal cracking units were modeled by entering the plant monitoring data, network topology, and heat exchanger geometries into a commercial heat exchanger network simulator, SmartPM. Fouling behaviors of vacuum residue streams and thermal cracker residue streams were identified and quantified. Both chemical reaction fouling and particulate fouling mechanisms were identified to be responsible for the fouling in these streams. Dynamic fouling models were fitted and used to predict fouling of these heavy petroleum streams, which fouled on both the shell and tube sides of the shell-and-tube heat exchangers.

Naphthenic acid corrosion characteristic and corrosion product film resistance of carbon steel and Cr5Mo low alloy steel in secondary vacuum gas oil

Although naphthenic acid corrosion (NAC) has been studied for many years, the mechanism of NAC is not fully understood. The objective of this paper is to study high-temperature NAC in secondary vacuum gas oil of an industrial crude oil vacuum distillation tower. A high-temperature autoclave was applied to conduct high-temperature corrosion test to investigate NAC behaviour of carbon steel and Cr5Mo low alloy steel at different sulphur contents and total acid numbers (TAN). The result shows that the corrosion rate of carbon steel and low alloy steel is high at low TAN and high TAN while it keeps at a low value at medium TAN. Corrosion product film on Cr5Mo low alloy steel surface is denser and more compact than that of carbon steel at high TAN. The chromium present in Cr5Mo low alloy steel plays an important role in NAC resistance by the formation of Cr7S8 film in the inner layer of the scale. Corrosion rates of the two steels in secondary vacuum gas oil are high at low TAN and high TAN, but low at medium TAN which are strange and different from previous experimental results conducted in non-industrial oil solution. A tentative explanation for this new phenomenon is also put forward.

Novel stationary phases based on asphaltenes for gas chromatography.

We present the results of investigations on the possibility of the application of the asphaltene fraction isolated from the oxidized residue from vacuum distillation of crude oil as a stationary phase for gas chromatography. The results of the investigation revealed that the asphaltene stationary phases can find use for the separation of a wide range of volatile organic compounds. The experimental values of Rohrschneider/McReynolds constants characterize the asphaltenes as stationary phases of medium polarity and selectivity similar to commercially available phases based on alkyl phthalates. Isolation of asphaltenes from the material obtained under controlled process conditions allows the production of a stationary phase having reproducible sorption properties and chromatographic columns having the same selectivity. Unique selectivity and high thermal stability make asphaltenes attractive as a material for stationary phases for gas chromatography. A low production cost from a readily available raw material (oxidized petroleum bitumens) is an important economic factor in case of application of the asphaltene stationary phases for preparative and process separations.

Hydrolysis Reaction Tendency of Low-Boiling Organic Chlorides To Generate Hydrogen Chloride in Crude Oil Distillation

The possibilities of hydrolysis of low-boiling organic chlorides in crude oil to generate a corrosive component, namely, hydrogen chloride was evaluated by using thermodynamic analysis under the operating conditions of crude oil distillation in refinery. Thermodynamic analysis was performed based on a previous work about the identity of chlorides and their distribution in YS crude oil of China. The Gibbs free energy change of the hydrolysis was estimated using the specified concentrations of steam and chloride hydrolysis products, and the results indicated that the low-boiling organic chlorides could hydrolyze to corrosive hydrogen chloride during atmospheric and vacuum distillation of crude oil from a thermodynamic point of view. Thermodynamic analysis results also showed that a high temperature and a low pressure are advantageous to the hydrolysis reaction of low-boiling organic chlorides. This thermodynamic analysis is helpful to understand the mechanism for the generation of hydrogen chloride during c...

Comparative analysis and evaluation of three crude oil vacuum distillation processes for process selection

There exists three practicable crude oil vacuum distillation processes and different processes have a significant impact on material and energy performances, including product yield, economic potential, heat recovery and the efficiencies of recoverable energy and recoverable exergy. Process selection is an important and difficult task for designers with various targets since the material and energy performances of a process do not coordinate with each other. In this work, an approach with simultaneous considerations of material and energy performances is proposed to comparatively analyze and evaluate the three processes, in order to provide insights for designers to screen a suitable process and vacuum furnace outlet temperature. The approach is conducted in three steps. In the first step, a simulation model is rebuilt to obtain basic material and energy data. In the second step, comparative analyses and evaluations are performed to measure the material and energy performances of three process options under the same operating conditions. In the last step, the variations of the material and energy performances are further investigated to determine the vacuum furnace outlet temperature. The results indicate that the cycle process has the highest product yield and best economic potential but the lowest efficiencies of recoverable energy and recoverable exergy, while the drawn process has the highest efficiencies of recoverable energy and recoverable exergy but the worst economic potential. The results also demonstrate that the selection of a vacuum distillation process and the determination of the vacuum furnace outlet temperature play a critical role in designing a crude oil vacuum distillation process.

Effect of polar organic substances on the distillates yield in atmospheric and vacuum distillation of crude oil

The influence of admixtures of chemically different polar organic solvents on the yield of distillates in atmospheric and vacuum distillation of crude oil has been studied. A comparative assessment of the compositions of asphaltenes isolated from vacuum residues has been made with the use of IR spectroscopy. The distillate recovery efficiency has been found to increase to the greatest extent in the presence of N-methylpyrrolidone as an additive during atmospheric distillation and ɛ-caprolactam in the case of vacuum distillation. However, the admixture of ɛ-caprolactam to crude oil does not provide an increase in aromaticity of vacuum-residue asphaltenes.

Feasibility of Microwave-Induced Combustion for Digestion of Crude Oil Vacuum Distillation Residue for Chlorine Determination

The microwave-induced combustion (MIC) method was applied for digestion of crude oil vacuum distillation residue for further chlorine determination. Ignition was performed by microwave radiation using a microwave oven designed for conventional pressurized wet digestion. Combustion was carried out using 20 bar of oxygen and NH4NO3 as the igniter. Water or H2O2, Na2CO3, and (NH4)2CO3 solutions were investigated for analyte absorption as well as the necessity of a reflux step. Digests were suitable to be analyzed by inductively coupled plasma optical emission spectrometry and ion chromatography. Accuracy was evaluated using spiked samples and certified reference materials of coal (BCR 181) and fuel oil (NIST 1634c). Recoveries for Cl were in the range of 98.4−100.2% for all investigated solutions using the reflux step. The agreement with certified values was better than 95% using 25 mmol L−1 (NH4)2CO3 as the absorbing solution and reflux step. Poor recoveries for Cl were observed using microwave-assisted wet...

Influence of the Speed Mixing-on Viscosity and Droplet Size of Oil in Water Emulsions

The viscosity and droplet size of oil in water emulsions prepared at different speed of mixing have been measured. Nonionic surfactant dissolved in fresh water has been used to emulsify the crude oil vacuum distillation residues from the Mexican petroleum refineries by mean of a dynamic mixer in batches of 600 mL. The aim of the present research was to reduce the crude oil vacuum distillation residues viscosity for its transport, storage, piping and burning in industrial boilers. The viscosity measurements were carried out in a range of temperature from 25 to 65°C and in a range of shear stress of 30–200 rpm. The results reveal that the droplet size decreases dramatically when the mixing speed is increased from 1000 to 1500 rpm while the droplet size is maintained very similar when the speed is increased from 1500 to 2500 rpm. On the other hand, the viscosity of the emulsion increases about 150 cP when the speed is increased from 1000 to 1500 rpm afterwards, it increases only about 110 cP when the speed is increased from 1500 to 2500 rpm. It is noteworthy that the weight fraction concentrations used of crude oil vacuum distillation residues, surfactant and water were 77%, 0.3%, and 22.7% respectively, and the flow behavior of the emulsion was found to be pseudoplastic.

Evaluation of the dermal carcinogenicity of lubricant base oils by the mouse skin painting bioassay and other proposed methods.

Lubricant base oils are petroleum products that are predominantly derived from the vacuum distillation of crude oil. Various types of refinement can be employed during the manufacturing process, and evidence suggests that certain of the associated process streams produce skin cancer. Polycyclic aromatic compounds (PACs), some of which are considered as the causative agents, are removed, concentrated or chemically converted during the refinement process. In order to understand the effects of various types of refinement processes on carcinogenic potential, 94 oils were evaluated in the mouse epidermal cancer bioassay. This Exxon database is unique, because of the wide range of crude oils and processing histories represented. Seven processing history classifications are described, and conclusions concerning the impacts of each refinement process on dermal carcinogenicity are discussed. This research also included an evaluation of selected biological and chemical test methods for predicting carcinogenic potential. These included a modified version of the Ames test for mutagenicity, as well as analytical characterizations of the polycyclic aromatic structures in the oils. For classification purposes, a sample was considered to be carcinogenic if it resulted in the production of two or more tumor-bearing animals (in test groups of either 40 or 50 animals). The modified Ames test was considered to be positive if the mutagenicity index was > or = 2.0, and PAC analyses were similarly designated as positive or negative according to proposed guidelines. All of the alternative test methods showed similar agreement with dermal carcinogenicity bioassay data; concordance values were > or = 80%. However, each test was incorrect in ca. 10%-20% of the cases evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)

A study of the mixture of coal and residue of the vacuum distillation of crude oil by thermal analysis

Thermal analysis was used for investigating the effect of the addition of the residue obtained from crude oil vacuum distillation on the carbonization process of brown coal. The kinetic analysis of the experimental TG curves was carried out by using the Coats-Redfern equation and then to select the most likely mechanism (functiong (α)) for particular decomposition stages of brown coal and its mixture with the residue. In the brown coal carbonization process the nucleation of a new solid phase is predominant. In the temperature range of the decomposition of coal (620–820 K) the addition of residue results a change in the mechanism of the thermal decomposition process — in the mixture three-dimensional diffusion processes and one-dimensional diffusion occur, depending on the composition. Above 730 K (secondary carbonation processes) the most likely mechanism involves the nucleation of a new solid phase as well as diffusion processes.

Role of thermal oxidation in the process of vanadium extraction from refinery coke (solid oil residues)

Since vanadium is a dispersed element characterized by a low Clark parameter (0.15), ores in which its content amounts to tenths of a percent are considered promising as feedstock for its isolation on an industrial scale. In view of the acute shortage of vanadium in the world market, an intense search is being carried out to find non-mineral types of feedstock for vanadium production. In heavy crude oils the vanadium concentration is comparable with its concentration in ores, but during atmospheric and vacuum distillation of crude oil the vanadium content in the residual products (fuel oil and tar) can be increased by factors of 2 and 4 respectively. A possible means of further concentrating petroleum vanadium is to burn boiler fuel (fuel oils) and collect the vanadium-rich ash. However, the presence of vanadium in boiler fuel leads to corrosion of the boiler equipment. The problem of catching the volatile vanadium oxides also arises [1]. Furthermore, it is necessary to burn boiler fuel with a high sulphur content, while the vanadium present in fuel oils poisons the catalysts of secondary oil refining processes, in particular hydrodesulphurization processes. Thus problems of the refining of heavy oil residues (OR) and industrial isolation of vanadium are interrelated and should evidently provide for the concentration of vanadium in solid oil residues and their separation from the liquid part of heavy OR. Vanadium was isolated from solid OR using cokes produced in the processes of slow coking, thermocontact cracking, flexicoking, and thermolysis of tar and fuel oil. From the viewpoint of more thorough oil refining, an important parameter characterizing the effectiveness of these processes is the liquid product/coke ratio. Certain indices of the given processes [2-6] are presented below:

Some aspects of the carbonization of vacuum distillation residue from crude oil

These studies concern the carbonization process of residues from vacuum distillation of crude oil. Some explanation aspects of the hypothetic reaction mechanism controlling the carbonization of high molecular weight components of crude oil are developed. On the basis of numerous experimental investigations, the thermal decomposition process can be divided into two stages, the first, from 670 to 790 K, in which the decomposition reactions take place and low and medium weight molecular compounds are emitted and the second stage, from above 790 K to 1000 K, in which cyclization, condensation and aromatization processes take place, and the degree of structural ordering in the solid products increases.

Carbonization of petroleum binders. 2. Oils from carbonization of petroleum binders

Changes of composition, structure, and contents of some functional groups, of oils from petroleum binders, in relation to temperature of carbonization from about 710 K to 1200 K have been investigated. Oils from carbonization of petroleum binders are of hydrocarbon type, and their elemental compositions are almost independent of carbonization temperature. During the thermal decomposition of these binders, about 75–80 wt % of gaseous and vapour products are emitted. As carbonization temperature increases, molecular weights of the oils increase from about 250 to about 290; their density, index of refraction, and molar refraction increase. Structural analysis of the oils showed that they contained about 30% of cyclic hydrocarbons (aromatic and cycloalkane) as well as alkanes. The number of rings in the average structural unit of oil increases with increase of carbonization temperature, especially the number of aromatic rings. About 60–70 vol % distills before 633 K under atmospheric pressure; the distillate is paraffinic, while the residue after distillation is aromatic-alicyclic. Oils from carbonization of P-70 asphalt have similar compositions and chemical natures, but lower molecular weights, than oils from carbonization of residues after vacuum distillation of crude oil. Oils from carbonization of pitch are decidedly aromatic.

Carbonization of petroleum binders. 1. Characteristics of solid products

Solid products of carbonization of residues (i.e. cokes) of vacuum distillation of crude oil, asphalt, and pitch have been studied. The objective was to determine the changes of composition and structure of cokes in relation to temperature. Investigations of elemental composition, functional group content, microscopic analysis, and X-ray diffraction of the products showed that with increasing temperature of carbonization, the degree of structure ordering, the dimensions of the pores, and the intensity of optical anisotropy of the cokes increases, as do the carbon, sulphur, and nitrogen contents; however, volatile matter, hydrogen, and functional-group contents in the cokes decrease.