A molecular insight into deoiled asphalt’s slurry-phase hydrocracking process

Qilu vacuum residue with Ni + V content of 120 ppm and Ca content of 40 ppm, is hard to process for fixed bed hydrocracking technology. In this work, solvent deasphalting process was used as a pretreatment for processing Qilu vacuum residue, and the yield of deasphalted oil could be up to 48.3 %, with less metal (Ni + V + Ca < 15 ppm) and asphaltene (<0.1 %) in deasphalted oil. The n-butane solvent in solvent deasphalting (SDA) process had higher selectivity for HC class, and correspondingly the relative abundance of HC class of deasphalted oil (DAO) was much higher than that of deasphalted oil (DAO). The abundance of DAO was higher than that of DOA when double bond equivalent (DBE) < 14 or carbon number (CN) < 46, and the relative abundance of SDA1-DOA was higher than that of SDA2-DOA when DBE < 20 or CN < 46. Deoiled asphalt was taken as the feed of slurry-phase hydrocracking (SHC) process, and the conversion ratio of deoiled asphalt in slurry-phase hydrocracking process could be more than 80 % for 240 min reaction. The conversion ratios of SDA1-DOA for SHC1-120 min and SHC1-240 min reactions were 66.92 % and 81.64 % respectively, and the conversion ratios of SDA2-DOA for SHC2-120 min and SHC2-240 min reactions were 70.19 % and 85.71 % respectively. Sulfur species and asphaltene changing rules at molecular level were determined to evaluate DOA’s slurry-phase hydrocracking process.     

Programmed automation of modulator cold jet flow for comprehensive two-dimensional gas chromatographic analysis of vacuum gas oils

A method is described for automating the regulation of cold jet flow of a comprehensive two-dimensional gas chromatograph (GCxGC) configured with flame ionization detection. This new capability enables the routine automated separation, identification, and quantitation of hydrocarbon types in petroleum fractions extending into the vacuum gas oil (VGO) range (IBP-540 degrees C). Chromatographic data acquisition software is programmed to precisely change the rate of flow from the cold jet of a nitrogen cooled loop modulator of a GCxGC instrument during sample analysis. This provides for the proper modulation of sample compounds across a wider boiling range. The boiling point distribution of the GCxGC separation is shown to be consistent with high temperature simulated distillation results indicating recovery of higher boiling semi-volatile VGO sample components. GCxGC configured with time-of-flight mass spectrometry is used to determine the molecular identity of individual sample components and boundaries of different molecular types.     

毛细管气相色谱/傅立叶变换红外光谱分析高温煤焦油中的重油馏分

 在原有工作基础上,采用毛细管气相色谱/傅立叶变换红外光谱-色谱保留指数(GC/FTIR-RI)联合解析技术,研究了高温煤焦油重油馏分的化学组成。分别从重油馏分F7(300～330℃)和F8(330～360℃)中分离并鉴定出70和61种化合物,了解到不同配煤工艺对煤焦油组成与性能的影响,从而获得了一些有意义的结果,为煤焦油的集中加工和新产品开发提供了重要依据     

辽河稠油减渣深度戊烷脱沥青的研究

以戊烷为溶剂,在脱沥青实验装置上对辽河稠油减渣进行梯级分离,得到轻脱油、重脱油和脱油沥青。在温度155℃~170℃、压力为4.0 MPa~7.0 MPa,考察了温度、压力变化对脱沥青油收率及性质的影响。用超临界萃取分馏的实验结果关联了脱沥青油残炭、N元素、Ni元素的脱除率。结果表明,压力升高、温度降低,脱沥青油收率增加,轻、重脱油的残炭值及S、N、Ni、V等元素含量升高,脱沥青油性质变差。在脱沥青油收率最高为74.23%时,Ca、Ni元素的脱除率分别为92.75%、74.50%;残炭的脱除率为62.13%;N、S元素的脱除率分别为40.17%、24.10%。超临界萃取馏分油的杂质脱除率与脱沥青油的杂质脱除率有较好的相关性。     

Replacement of Benzene and Carbon Tetrachloride with Less Hazardous Eluants in Chromatography for the Determination of Saturates Content of Hydrocarbon Oils

Abstract

The method for the separation of heavy petroleum hydrocarbons Into structural types-saturates, aromatics and polar materials has been modifled. The eluants, carbon tetrachloride and benzene that are carcinogenic and toxic, were successfully replaced with dichloromethane and petroleum spirit mixtures (35:65 and 82:18, respectively). The modified method was successfully applied to raffinates, extracts, hydrocracker products, heavy distillates, atmospheric and vacuum bottoms and other deasphalted residues (maltenes).

An Improved handling technique was developed for hydrocarbon oils containing asphaltenes utilizing a preliminary deasphalting step with n-pentane.

The precision of the technique was established for the saturates measured at ± 0.4% for a wide range of hydrocarbon oils.     

Some Properties of Petroleum Sulfoxides Suitable for Extraction in Hydrometallurgy

Several fractions of diesel fuel recovered from Arlan crude oil were treated with hydrogen peroxide, and the sulfoxides formed by oxidation of petroleum sulfides were isolated with aqueous sulfuric acid. The water solubility of these sulfoxides and their limiting extraction capacity with respect to neodymium nitrate were determined. Correlations between several characteristics of the petroleum sulfoxides [water solubility, limiting extraction capacity with respect to neodymium(III) nitrate, phase separation time under standard conditions, and viscosity] and the boiling range of corresponding petroleum fractions were analyzed.     

Automatic simulated distillation of heavy petroleum fractions up to 800°C TBP by capillary gas chromatography. Part I: Possibilities and limits of the method

The characterization of heavy petroleum fractions is essential for the design and improvement of cracking plants converting heavy feedstock into valuable “white” products. Conventional simulated distillation methods using packed columns are unsuitable for this purposes, being limited to boiling points up to about 600°C. The method presented is able to cover a boiling points interval ranging from about 150°C up to around 800°C. It employs a short, nonpolar, highly thermostable capillary column routinely operated at temperatures around 430°C. The analytical system is based on a high temperature versions of a fully automatic, capillary dedicated gas chromatograph. The experimental data demonstrate that cold on-column injection is the sole sampling system suitable for such heavy compounds. The conversion of the retention times into boiling points, based on the use of low molecular weight polyethylenes, is extremely reliable, as demonstrated by the excellent retention time reproducibilities. The lower part (up to 550–600°C TBP) of the boiling point distribution curves of heavy petroleum fractions obtained on capillary columns fits well with the corresponding distribution curves based on packed column data. For the petroleum fractions fully eluted from the column the quantitative results obtained either using internal standards or by direct processing of the elution curves are in excellent agreement (less than 0.3 weight% differences). The method has been applied to the determination of the true boiling points corresponding to short path vacuum distillation (DISTACT) cut points over 300°C.     

Will Zeolite‐Based Catalysis be as Relevant in Future Biorefineries as in Crude Oil Refineries?

Transition from petroleum‐ to biomass‐based fuel economy will require new conversion strategies. In a petroleum refinery, particular hydrocarbon fractions from crude oil are catalytically converted into high‐grade fuels. Certain zeolite catalysts are performing exceptionally well. Unlike petroleum fractions, biomass‐derived compounds have a high oxygen content requiring low‐temperature catalytic aqueous phase processes for selective conversion and stability of zeolite catalysts in hot liquid water. It will be shown that recent developments in zeolite synthesis and modification allow adapting zeolite properties to achieve selective conversion of biomass compounds/fractions as well.     

Optimization of tocopherol concentration process from soybean oil deodorized distillate using response surface methodology

Soybean oil deodorized distillate is a product derived from the refining process and it is rich in high value-added products. The recovery of these unsaponifiable fractions is of great commercial interest, because of the fact that in many cases, the "valuable products" have vitamin activities such as tocopherols (vitamin E), as well as anticarcinogenic properties such as sterols. Molecular distillation has large potential to be used in order to concentrate tocopherols, as it uses very low temperatures owing to the high vacuum and short operating time for separation, and also, it does not use solvents. Then, it can be used to separate and to purify thermosensitive material such as vitamins.In this work, the molecular distillation process was applied for tocopherol concentration, and the response surface methodology was used to optimize free fatty acids (FFA) elimination and tocopherol concentration in the residue and in the distillate streams, both of which are the products of the molecular distiller. The independent variables studied were feed flow rate (F) and evaporator temperature (T) because they are the very important process variables according to previous experience. The experimental range was 4-12 mL/min for F and 130-200 degrees C for T. It can be noted that feed flow rate and evaporator temperature are important operating variables in the FFA elimination. For decreasing the loss of FFA, in the residue stream, the operating range should be changed, increasing the evaporator temperature and decreasing the feed flow rate; D/F ratio increases, increasing evaporator temperature and decreasing feed flow rate. High concentration of tocopherols was obtained in the residue stream at low values of feed flow rate and high evaporator temperature. These results were obtained through experimental results based on experimental design.     

FT-Raman and photoacoustic infrared spectroscopy of Syncrude heavy gas oil distillation fractions

FT-Raman and photoacoustic (PA) infrared spectra of six distillation fractions derived from Syncrude heavy gas oil (HGO), which has a boiling range from 343 to 524 degrees C, were analyzed in detail in this study. Most of the information on the fingerprint region (200-1,800 cm(-1)) is provided by the FT-Raman spectra, which display approximately 30 bands that are assignable to functional groups in alkanes or aromatics. Monocyclic, bicyclic and tricyclic aromatics in the six fractions were also monitored using bands in this region. The C-H stretching region in both the FT-Raman and PA infrared spectra of the HGO distillation fractions was analyzed according to a curve-fitting algorithm used in previous investigations of samples with lower boiling points. The PA spectra of the HGO fractions were also analyzed by integration. The curve-fitting results show that the frequencies of the 11 Raman and 8 infrared bands used to model the aliphatic (approximately 2,775-3,000 cm(-1)) parts of the respective spectra are approximately constant across the entire HGO boiling range. These band positions are consistent with the results obtained in earlier studies of other distillation fractions obtained from Syncrude sweet blend. Both curve-fitting and integration show that the respective proportions of CH(2) and CH(3) groups do not vary significantly within the HGO region.     

Effect of a thin spreading solvent film on the efficiency of the hexadecan-1-ol monolayer deposited for water evaporation retardation

The influence of a thin spreading solvent film (ethanol, diethyl ether, and three fractions of petroleum ether boiling at 30–60 °C, 60–90 °C, and 90–120 °C) on the properties of hexadecan-1-ol (C₁₆H₃₃OH) monolayers at the air—water interface was studied. The specific evaporation resistance and the surface pressure were determined to describe the spreading behavior of the C₁₆H₃₃OH monolayers. The physical properties of the solvents and the images obtained in an atomic force microscope were examined. The time of establishing the equilibrium spreading surface pressure of monolayers can be reduced using a more volatile solvent with a lower boiling point and a lower relative density. The influence of the monolayer nature on water evaporation corresponds to the order of changing the solvent spreading rate: petroleum ether (30–60 °C) > diethyl ether > ethanol > petroleum ether (60–90 °C) > petroleum ether (90–120 °C). The monolayers formed upon petroleum ether (30–60 °C) spreading form a film with a less deficient and relatively planar surface. When ethanol is used as a spreading solvent, water evaporation is accelerated rather than retarded, while petroleum ether (30–60 °C) is more appropriate for this purpose.     

Determination of the boiling-point distribution by simulated distillation from n-pentane through n-tetratetracontane in 70 to 80 seconds

This work presents the carrying out of boiling-point distributions by simulated distillation with direct-column heating rather than oven-column heating. Column-heating rates of 300 degrees C/min are obtained yielding retention times of 73 s for n-tetratetracontane. The calibration curves of the retention time versus the boiling point, in the range of n-pentane to n-tetratetracontane, are identical to those obtained by slower oven-heating rates. The boiling-point distribution of the reference gas oil is compared with that obtained with column oven heating at rates of 15 to 40 degrees C/min. The results show boiling-point distribution values nearly the same (1-2 degrees F) as those obtained with oven column heating from the initial boiling point to 80% distilled off. Slightly higher differences are obtained (3-4 degrees F) for the 80% distillation to final boiling-point interval. Nonetheless, allowed consensus differences are never exceeded. Precision of the boiling-point distributions (expressed as standard deviations) are 0.1-0.3% for the data obtained in the direct column-heating mode.     

Characterization of a heavy oil–propane system in the presence or absence of asphaltene precipitation

When a light hydrocarbon solvent is injected into a heavy oil reservoir under a sufficiently high reservoir pressure, asphaltene precipitation occurs so that the heavy oil is in situ deasphalted during a hydrocarbon solvent-based heavy oil recovery process. The physicochemical properties of this in situ deasphalted heavy oil are rather different from those of the original crude oil in the heavy oil reservoir. In this paper, a heavy oil sample is saturated with a typical light hydrocarbon solvent (i.e., propane) under different saturation pressures in a see-through windowed high-pressure saturation cell. The heavy oil–propane system is characterized by measuring and comparing several important physicochemical properties of the propane-saturated heavy oil samples under different saturation pressures and the flashed-off heavy oil samples, such as the solubility, oil-swelling factor, density, viscosity, asphaltene content, hydrogen and carbon aromaticities. When the heavy oil is saturated with propane at P ≤ 780 kPa and T = 20.8 °C, there is no observable asphaltene precipitation and deposition under a microscope camera. The respective properties of the propane-saturated heavy oil samples taken from the upper and lower parts of the saturation cell are measured and found to be essentially the same within the experimental errors so that the entire system is considered to be almost homogeneous. If the saturation pressure is increased to P = 850 kPa, strong asphaltene precipitation occurs and some large asphaltene particles are deposited onto the bottom of the saturation cell. In this case, the heavy oil is deasphalted and the flashed-off heavy oil has lower density, viscosity, asphaltene content, hydrogen and carbon aromaticities than those of the original heavy crude oil.     

Characterization and routine determination of certainnon-basic nitrogen types in high-boiling petroleum distil-lates by means of linear elution adsorption hromato-graphy

Carbazoles, 1,2-benzcarbazoles, and 3,4-benzcarbazoles were identified as major non-basic nitrogen types in a straight-run California gas oil, Indoles and 2,3-benzcarbazoles were found to be absent. A routine procedure using ion exchange, linear elution adsorption chromatography, and ultraviolet spectrophotometric analysis is described for the rapid determination of the indoles, carbazoles, and benzcarbazoles (except N-alkyl derivatives) in straight-run heavy distillates (400 to 1000° F). The relative distribution of various nitrogen types in a number of crude petroleum fractions is reported. In the 600–10000° F boiling range, carbazoles plus benzcarbazoles account for 25 to 70% of the total nitrogen in straight-run samples. Within experimental error, tlie sum of nitrogen as carbaxoles and benzcarbazoles plus bases titratable in acetic anhydride accounts for all of the nitrogen of such samples. The carbazoles and 1,2-benzcarbazoles were clearly identifiable as major components of every crude oil studied.     

神府煤液化油加氢精制过程中硫氮化合物分布的变化

采用实沸点蒸馏对神府煤液化油及其加氢精制油做了馏分切割,并采用GC-PFPD与GC-NCD对液化油与精制油中的硫氮化合物类型进行了分析,研究了液化油加氢精制过程中硫氮化合物分布的变化。结果表明,液化油中硫含量随窄馏分的馏程由低到高呈现"U"型分布,氮的分布基本上随窄馏分沸点温度的升高而增大,氮的含量远高于硫的含量;经过固定床加氢精制后,97%的硫和98.9%的氮得到脱除。液化油中苯并噻吩和二苯并噻吩等二环和三环化合物占93.25%;经过加氢处理之后,硫醇、硫醚、噻吩类等低沸点含硫化合物基本消失,难脱除组分主要以苯并噻吩类、二苯并噻吩类为主。液化油中含氮化合物主要以五元杂环中性氮化物为主,占54.96%;碱性氮化物主要以苯胺类为主,占23.22%,喹啉类相对较少;经过加氢处理之后,脂肪胺类含氮化合物被完全脱除,精制油中残留的氮主要以碱性氮化物喹啉类与苯胺类含氮化合物存在。     

Recovery of some common solvents from protective clothing breakthrough indicator pads by microwave-solvent extraction and gas chromatography

The efficiency of solvent adsorption using Permea-Tec general solvent pads, used for the detection of chemical breakthrough of protective clothing, was determined for methanol, acetone, ethyl methyl ketone, trichloroethylene (TriCE), tetrachloroethylene (TetCE), toluene, m-xylene, and D-limonene. Known volumes of single or mixed solvents were added to pads in the range 0.2-5.0 microliters (0.16-8.13 micrograms). After microwave-solvent extraction (ME) into hexan-1-ol, the samples (0.5-3.0 microliters) of the filtered and extracted solutions were analyzed by gas chromatography. All solvents exhibited > 97% adsorption on the pads at spiking levels of 0.48-0.98 microgram for each solvent. The solvent recovery for the system was calculated for each solvent, with solvents with boiling points below 110 degrees C showing recoveries of > 90%, and with solvents with boiling points above 110 degrees C showing recoveries from 80 to 90%. The recovery precision was good (RSD < or = 4%) for all solvents over the range 1.0-2.5 microliters of applied solvents to pads for ME and 1.0 microliter of extracted solutions for GC analysis.     

重楼中薯蓣皂甙元的反相高效液相色谱测定

采用高效液相色谱法测定了重楼中薯蓣皂甙元的质量分数。样品先经甲醇提取,再经酸水解,将重楼甾体皂甙转变成薯蓣皂甙元,以ＳｙｍｍｅｔｒｙＣ８柱为色谱柱,以Ｖ（乙腈）∶Ｖ（水）＝７５∶２５溶液为流动相,检测波长２０３ｎｍ,重复性较好,结果令人满意。     

FT-Raman and photoacoustic infrared spectroscopy of syncrude light gas oil distillation fractions

FT-Raman and photoacoustic (PA) infrared spectra of 12 distillation fractions derived from Syncrude light gas oil (LGO), which has a boiling range from 195 to 343 degrees C, were analyzed in detail in this study. In the fingerprint region (200-1800 cm(-1)) most of the information is obtained from the FT-Raman spectra, which display 36 bands that are assignable to various alkyl or aryl functional groups. Monocyclic, bicyclic and tricyclic aromatics in the 12 fractions were also characterized using Raman bands in this region. The corresponding section of the infrared spectra is much simpler, displaying a relatively small number of bands due to either aromatic or aliphatic CH(n) (n=1, 2 or 3) groups. The Cz.sbnd;H stretching region in both FT-Raman and PA infrared spectra of the LGO distillation fractions was curve-fitted according to procedures established in previous investigations of Syncrude samples with various boiling ranges. The PA spectra of the LGO fractions were also analyzed using an accepted integration strategy that requires no a priori assumptions with regard to the number of constituent bands or their shapes. The curve-fitting results show that the frequencies of the 11 Raman and eight infrared bands used to model the aliphatic ( approximately 2775-3000 cm(-1)) parts of the respective spectra decrease systematically as the median boiling points of the LGO fractions increase. These band positions are consistent with those determined in earlier studies of other distillation fractions. Both curve fitting and integration show that the abundance of CH(2) groups increases at the expense of CH(3) groups as the boiling points of the fractions increase within the LGO region.     

Generalized correlation for predicting the kinematic viscosity of liquid petroleum fractions

A two-parameter viscosity model proposed previously for pure liquids is extended to correlate the kinematic viscosity–temperature behavior for liquid petroleum fractions. The coefficients in the viscosity equation are related to the characterization properties of the petroleum fractions and a generalized kinematic viscosity–temperature correlation is then developed, which needs only specific gravity at 15.6°C and 50% boiling point as input parameters. The present method, when tested by predicting the experimental kinematic viscosities of 47 fractions from 15 world crude oils with total 250 data points, yielded reasonable results with an overall average absolute deviation of 4.2%.     

A multi-dimensional high performance liquid chromatographic method for fingerprinting polycyclic aromatic hydrocarbons and their alkyl-homologs in the heavy gas oil fraction of Alaskan North Slope crude

We report an offline multi-dimensional high performance liquid chromatography (HPLC) technique for the group separation and analysis of PAHs in a heavy gas oil fraction (boiling range 287-481 degrees C). Waxes present in the heavy gas oil fraction were precipitated using cold acetone at -20 degrees C. Recovery studies showed that the extract contained 93% (+/-1%; n=3) of the PAHs that were originally present while the wax residue contained only 6% (+/-0.5%; n=3). PAHs present in the extract were fractionated, based on number of rings, into five fractions using a semi-preparative silica column (normal-phase HPLC). These fractions were analyzed using reverse-phase HPLC (RP-HPLC) coupled to a diode array detector (DAD). The method separated alkyl and un-substituted PAHs on two reverse-phase columns in series using an acetonitrile/water mobile phase. UV spectra of the chromatographic peaks were used to differentiate among PAH groups. Further characterization of PAHs within a given group to determine the substituent alkyl carbon number used retention time matching with a suite of alkyl-PAH standards. Naphthalene, dibenzothiophene, phenanthrene and fluorene and their C1-C4 alkyl isomers were quantified. The concentrations of these compounds obtained using the current method were compared with that of a GC-MS analysis obtained from an independent oil chemistry laboratory.