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1.
Hu Jia Jihui Ni Wanfen Pu Ping Yue Hang Jiang Jianjun Yang 《Journal of Thermal Analysis and Calorimetry》2014,118(3):1707-1714
In the previous study, the oxidation behavior of four Chinese crude oils (Oil 1 to 4) in the presence and absence of rock cuttings was investigated by thermogravimetry/derivative thermogravimetry (TG/DTG) techniques and oxidation tube experiments. The present work investigates the thermal behavior of these oils by combining DTG–DTA method. First, we conducted comparative analysis about mass loss rate from DTG curves and endothermic/exothermic phenomenon from DTA curves attempting to clarify the endothermic or exothermic mechanism in crude oil low-temperature oxidation. Finally, we combined the thermal analysis method with low-temperature oil oxidation tube experiment in porous media to ascertain, whether the two methods are consistent in the aspect of low-temperature oxidation mechanism of crude oil by O2 consumption rate and CO2 generating rate (carbon bond stripping reaction rate). Results show that crude oils undergo an endothermic oxidation behavior during low-temperature oxidation stage, suggesting the decomposition of hydrocarbon components. Clay can play a catalytic effect on low-temperature oil oxidation. The results of DTG–DTA tests can also better reflect oil oxidation mechanism under real conditions. 相似文献
2.
Effect of different clay concentrations on crude oil combustion kinetics by thermogravimetry 总被引:1,自引:0,他引:1
The objective of this research was to investigate the effect of different clay composition and concentrations on the thermal
behaviour and kinetics of heavy crude oil in limestone matrix by thermogravimetry (TG/DTG). In TG/DTG experiments, three distinct
reaction regions were identified in all of the crude oil + limestone mixture known as low temperature oxidation (LTO), fuel
deposition (FD) and high temperature oxidation (HTO) respectively. Addition of clay to porous matrix significantly affected
the reaction regions. Significant reduction of activation energy due to addition of clay to crude oil indicates the catalytic
effect of clay on crude oil combustion. 相似文献
3.
Kök M. V. Pokol G. Keskin C. Madarász J. Bagci S. 《Journal of Thermal Analysis and Calorimetry》2004,75(3):781-789
In this study the combustion characteristics of crude oils (Karakuę and Beykan) in the presence of a limestone matrix were
determined using the thermogravimetry (TG/DTG). Experiments were performed at a heating rate of 10°C min-1, whereas the air flow rate was kept constant at 10 L h-1 in the temperature range of 20-900°C. In combustion with air, three distinct reaction regions were identified in all crude
oil/limestone mixtures studied known as low temperature oxidation (LTO), fuel deposition (FD) and high temperature oxidation
(HTO). The individual activation energies for each reaction region may be attributed to different reaction mechanisms, but
they do not give any indication of the contribution of each region to the overall reactivity of the crude oils. Depending
on the characteristics, the mean activation energy of samples varied between 50.3 and 55.8 kJ mol-1.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
In
this research, thermal characterization and kinetics of Karakus crude oil
in the presence of limestone matrix is investigated. Thermogravimetry (TG/DTG)
is used to characterize the crude oil in the temperature range of 20-900°C,
at 10°C min -1 heating rate using air
flow rate of 20 mL min -1. In combustion
with air, three distinct reaction regions were identified known as low temperature
oxidation (LTO), fuel deposition (FD) and high temperature oxidation (HTO).
Five different kinetic methods used to analyze the TG/DTG data to identify
reaction parameters as activation energy and Arrhenius constant. On the other
hand different f(α) models from literature
were also applied to make comparison. It was observed that high temperature
oxidation temperature (HTO) activation energy of Karakus crude oil is varied
between 54.1 and 86.1 kJ mol -1, while low
temperature oxidation temperature (LTO) is varied between 6.9 and 8.9 kJ mol -1. 相似文献
5.
Yi-Bo Li Jin-Zhou Zhao Wan-Fen Pu Hu Jia Huan Peng Dong Zhong Sheng-Kui Wang 《Journal of Thermal Analysis and Calorimetry》2013,113(2):579-587
This research aimed at the investigation of the effect of different metallic additive on the combustion and kinetic behavior of crude oil. For this purpose, the thermal behavior of the oil-only and oil–metallic salts mixtures were studies by the thermogravimetry (TG)/derivative thermogravimetry and differential scanning calorimetry (DSC) on heating rate at 10 °C min?1. The result shows that Dagang crude oil exhibited apparent low temperature oxidation (LTO), fuel deposition, and high temperature oxidation processes. With the addition of metallic salts, the LTO process has been shortened and samples added CuSO4, CrCl3·6H2O, and AlCl3·6H2O achieved a much lower peak temperature than that of oil. Based on the Arrhenius model, metallic additives were proven to have obvious influence on the combustion activation energy. And, by comprehensive analysis of TG/DSC profile and activation energy, ZnSO4 exhibited a positive influence on light crude oil combustion during the high pressure air injection process. 相似文献
6.
This research presents the results of an experimental study on the determination of pyrolysis behaviour and kinetics of six
crude oils by differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). Crude oil pyrolysis indicated two main
temperature ranges where loss of mass was observed. The first region between ambient to 400°C was distillation. The second
region between 400 and 600°C was visbreaking and thermal cracking. Arrhenius-type kinetic model is used to determine the kinetic
parameters of crude oils studied. It was observed that as crude oils gets heavier (°API decreases) cracking activation energy
increases. Activation energy of cracking also show a general trend with asphaltene content.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
M. V. K?k 《Journal of Thermal Analysis and Calorimetry》2009,97(2):397-401
In this research, the effect of different lithology (limestone and sandstone) on the combustion of light crude oils was investigated
using thermal analysis techniques. Three distinct reaction regions were identified in all of the crude oil+limestone and sandstone
mixtures, known as low temperature oxidation (LTO), fuel deposition (FD) and high temperature oxidation (HTO), respectively.
Kinetic analysis of the crude oil+limestone and sandstone mixtures was performed using Coats and Redfern method and the results
are discussed. 相似文献
8.
J. A. Murillo-Hernández S. López-Ramírez J. M. Domínguez C. Duran-Valencia I. García-Cruz J. A. González-Guevara 《Journal of Thermal Analysis and Calorimetry》2009,95(1):173-179
A survey on the effect of ionic liquids (ILs) over the thermal stability of a heavy Mexican oil was performed. ILs used were
based on [Cnim]+ and [Cnpyr]+ organic cations with FeCl4− metal anion. Mixtures of heavy crude oil (HCO) with ILs show three oxidation zones: low temperature oxidation (LTO), full
deposition (FD) and high temperature oxidation (HTO). Thermal stability and mass loss decrease in the LTO zone but increase
in the FD and HTO zones for every ILs used. The activation energy of the oxidation is influenced by the ILs in the HTO zone.
It decreases when increasing the size of the organic radical substitute in the cation of the ILs while it increases with the
presence of hydroxyl groups. The influence of electronic structure and reactivity indexes are rationalized to understand the
variations of activation energy obtained of the reaction systems. Among all cations used, cation-3 (IL-3) shows the greater
value of HOMO-LUMO gap as well as the lower activation energy. 相似文献
9.
Jaap S. Sinninghe Damst W. Irene C. Rijpstra Jan W. de Leeuw Gerard W. M. Lijmbach 《Journal of separation science》1994,17(6):489-500
Five crude oils with varying sulfur contents (0.1 – 4.7%) were characterized on a molecular level for organically-bound sulfur. Aromatic fractions were analyzed by GC-(MS) and asphaltene and polar fractions were analyzed by flash pyrolysis-GC-(MS). The polar fractions were also desulfurized with Raney Ni and the hydrocarbons formed were analyzed by GC-MS. Major sulfur compounds in the aromatic fractions were identified as alkylbenzo- and alkyldiben-zothiophenes. The flash pyrolyzates of the asphaltene contained alkylthiophenes and alkylbenzothiophenes as major compounds, depending on the thermal maturity of the oil. Generally, the sulfur-rich crude oils contained relatively more sulfur compounds. The flash pyrolyzates of polar fractions contained a variety of sulfur compounds (alkylthiolanes, alkylthianes, terpenoid sulfides, alkylbenzothiophenes) with substantial differences between different crude oils. Raney Ni desulfurization of the polar fraction yielded hydrocarbons dominated by n-alkanes, but isoprenoid alkanes, n-alkylcyclohexanes, mid-chain methylalkanes, tricyclic terpanes, hopanes and steranes were also present. These hydrocarbons show a potential to fingerprint crude oils since their distribution patterns are more characteristic than those of the hydrocarbons present in the saturated hydrocarbon fraction. 相似文献
10.
Thermal analysis of crude oils and comparison with SIMDIST and TBP distillation data 总被引:1,自引:0,他引:1
M. A. Ali M. A. B. Siddiqui S. M. J. Zaidi 《Journal of Thermal Analysis and Calorimetry》1998,51(1):307-319
Four commercial Saudi Arabian crude oils were characterized by thermogravimetry (TG) and differential thermal analysis (DTA).
These crude oils, Arab Berri (AB), Arab Light (AL), Arab Medium (AM) and Arab Heavy (AH), were also subjected to the traditionally
employed true boiling point (TBP) distillation and simulated distillation (SIMDIST). The TG/DTA data show that the hydrocarbons
present in these crude oils fall into four groups: the volatiles, the low molecular weight, the medium molecular weight and
the high molecular weight compounds. These four types of hydrocarbons were observed to display certain trends, such that the
volatile and low molecular weight hydrocarbons increased, while the medium and high molecular weight hydrocarbons decreased
with the lightness of the crude. The volatile contents of AB, AL, AM and AH crude oils up to 280°C were 50.1, 42.2, 42.3 and
38.5 mass percent, respectively. This confirms that AB is the lightest of these crude oils with maximum volatile content.
The mass percentage loss from the TG results is in good agreement with the percentage distilled from TBP (ASTM D 2892) and
SIMDIST. During evaporation, the TG mass loss follows a similar trend to those of the TBP and SIMDIST results and thus behaves
like distillation. During the oxidative degradation, the TG curve shows a higher mass loss as compared to the distillation
data. The higher deviation of the TG mass loss and percentage distilled at the higher-temperature end of the curve may be
attributed to the higher content of asphaltenes and carbonaceous material present in AH as compared to the AB crude oil. At
around 200°C, the TG mass loss curve intersects the TBP and SIMDIST curves and shows a derivation from distillation behaviour.
This intersection temperature of the TG and distillation curves is observed to decrease with the heaviness of the crude and
can be an indication of the onset of thermal degradation of hydrocarbons present in the crude oil. On the whole, the TG data
closely resemble the distillation results. 相似文献
11.
Non-isothermal kinetic analysis and feasibilty study of medium grade crude oil field 总被引:1,自引:0,他引:1
M. V. Kök 《Journal of Thermal Analysis and Calorimetry》2008,91(3):745-748
In this research, non-isothermal kinetics and feasibility study of medium grade crude oil is studied in the presence of a
limestone matrix. Experiments were performed at a heating rate of 10°C min−1, whereas the air flow rate was kept constant at 50 mL min−1 in the temperature range of 20 to 600°C (DSC) and 20 to 900°C (TG). In combustion with air, three distinct reaction regions
were identified in all crude oil/limestone mixtures, known as low temperature oxidation (LTO), fuel deposition (FD) and high
temperature oxidation (HTO). The activation energy values were in the order of 5–9 kJ mol−1 in LTO region and 189–229 kJ mol−1 in HTO region. It was concluded that the medium grade crude oil field was not feasible for a self-sustained combustion process. 相似文献
12.
低温氧化是注空气采油及原位燃烧采油技术中的重要化学反应,为深入认识原油在有氧环境下复杂热反应过程中的低温氧化特性,我们采用热重/差热分析法(TG/DTA)研究了线性升温和等温条件下马瑞(Merey)原油的热反应行为。 结果表明,Merey原油在空气及线性升温条件下的受热过程分4个阶段:气化段、低温氧化段、热解段和高温氧化段;相邻阶段的物理、化学主导过程的重叠增加了分析原油热反应特征的难度。 升温速率提高,气化段和低温氧化段的终止温度不变;热解段和高温氧化段的终止温度以及热解段的峰温随升温速率的增加而升高。 N2气与空气下Merey原油的热重/微分热重(TG/DTG)数据对比表明,升温速率越高,空气下的高温氧化段与热解段重叠程度越大,这有利于燃烧但会降低原油采收率。 空气下等温时的TG/DTA结果表明随升温速率增加,升温至300 ℃时的失重率降低,不利于原油轻组分的气化。 反应温度越高,气化过程时间越长,失重分数越大。 Merey原油在低于300℃时低温氧化反应不是主导反应。 相似文献
13.
Michelle Gonçalves Mothé Cheila Gonçalves Mothé Carlos Henrique Monteiro de Carvalho Marcia Cristina Khalil de Oliveira 《Journal of Thermal Analysis and Calorimetry》2013,113(2):525-531
Present study investigates thermal behavior of two heavy crude oils with different °API values by simultaneous thermogravimetry–differential scanning calorimetry–fourier transform infrared spectroscopy (TG–DSC–FTIR), and an evaluation of the chemical element levels present in the oils’ ashes was done by energy dispersive X-ray fluorescence spectrometry. TG and DSC curves were obtained for two samples in nitrogen atmosphere. Among all inorganic components evaluated, the highest concentration in the two oils was SO3. Thus this study may contribute to a better understanding of the thermal behavior of heavy crude oils and their composition. 相似文献
14.
Joseph J. Chen Dr. Martin Hürlimann Dr. Jeffrey Paulsen Dr. Denise Freed Dr. Soumyajit Mandal Dr. Yi‐Qiao Song 《Chemphyschem》2014,15(13):2676-2681
Crude oils, which are complex mixtures of hydrocarbons, can be characterized by nuclear magnetic resonace diffusion and relaxation methods to yield physical properties and chemical compositions. In particular, the field dependence, or dispersion, of T1 relaxation can be used to investigate the presence and dynamics of asphaltenes, the large molecules primarily responsible for the high viscosity in heavy crudes. However, the T2 relaxation dispersion of crude oils, which provides additional insight when measured alongside T1, has yet to be investigated systematically. Here we present the field dependence of T1‐T2 correlations of several crude oils with disparate densities. While asphaltene and resin‐containing crude oils exhibit significant T1 dispersion, minimal T2 dispersion is seen in all oils. This contrasting behavior between T1 and T2 cannot result from random molecular motions, and thus, we attribute our dispersion results to highly correlated molecular dynamics in asphaltene‐containing crude oils. 相似文献
15.
Luis A. Alcázar-Vara Luis S. Zamudio-Rivera Eduardo Buenrostro-González 《Journal of Dispersion Science and Technology》2016,37(11):1544-1554
This study presents an investigation about the influence of resins and asphaltenes, extracted from two Mexican crude oils (light and heavy oil samples), on the asphaltene aggregation inhibition, rheological behavior, and waterflood oil-recovery. Resins and asphaltenes were characterized by means of elemental analysis, metals analysis by atomic absorption, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, and electrospray ionization mass spectrometry (ESI-MS) in order to evaluate the effect of their structural parameters on the phenomena studied. Efficiency of the resins fraction as natural inhibitors of asphaltene aggregation was evaluated trough ultraviolet–visible (UV–vis) spectroscopy. Results showed better efficiencies of resins on asphaltene aggregation inhibition at resin/asphaltene (R/A) ratios close to unity and at high temperature. In addition, efficiencies were influenced by structural characteristics of the asphaltene–resin system. Rheological behavior of the heavy crude oil sample was significantly influenced by the presence of asphaltenes and resins. Finally, asphaltenes and resins played an important role on wettability and waterflood oil-recovery. 相似文献
16.
Michelle G. Mothé Carlos H. M. Carvalho Eliana F. C. Sérvulo Cheila G. Mothé 《Journal of Thermal Analysis and Calorimetry》2013,111(1):663-668
The present work investigates the thermal behavior and kinetic of four types of petroleum samples: a medium crude oil—P1, one heavy oil—P2, and two extra heavy oils—P3 and P4 by TG, DTG, and DSC methods. Thus, this study may contribute to the characterization of petroleum with different °API values. 相似文献
17.
Mustafa Versan Kok 《Journal of Thermal Analysis and Calorimetry》2011,105(2):411-414
In this research, thermo-oxidative reactions of crude oils of different origin are determined in limestone matrix using simultaneous
thermogravimetry and differential thermal analysis (TG–DTA) systems. Two different reaction regions were identified known
as low temperature (LTO) and high temperature oxidation (HTO). Kinetic parameters of the samples were determined by four different
methods and the results are discussed. 相似文献
18.
M. Tomassetti G. Favero L. Campanella 《Journal of Thermal Analysis and Calorimetry》2013,112(1):519-527
A thermal degradation study using TG–DTG thermogravimetry was performed on three saturated fatty acids esterified with glycerol (i.e. glyceryl-tristearate (C18), -tripalmitate (C16) and -trimyristate (C14)) at different heating rates. In addition, thermogravimetry (TG) and derivative thermogravimetry (DTG) of glyceryl di-stearate and glyceryl mono-stearate were also carried out at different heating rates. A deconvolution procedure applied to the first process and overlapping at least two steps between about 200 and 350 °C, enabled the activation energy of decomposition to be determined both by the Kissinger and the Ozawa–Flynn–Wall isoconversional methods for the deconvoluted steps of the above-mentioned fatty acids. 相似文献
19.
Ayman M. Atta Maher A. Elsockary Osama F. Kandil Zakaa M. Mohamed 《Journal of Dispersion Science and Technology》2013,34(1):7-19
Polyethylene acrylic acid copolymer (PEAA) was modified with different types of alkanols and hydroxybenzoic acids to produce three types of esterified grafts. The molecular structures of the synthesized dispersants were performed using 1H NMR analysis. The molecular weights of the synthesized dispersants were determined by GPC technique. The activity of PEAA derivatives as asphaltene stabilizer in the crude oil was evaluated by means of flocculation measurements. The effect of asphaltenes on the rheological behavior of highly asphaltenic crude oils was studied to evaluate the transportation parameters of crude oils. The rheological properties were measured at different temperature ranges of 5°C to 25°C in presence and absence of PEAA additives. It was observed that the PEAA having side chain lengths below C16 show non‐Newtonian pseudoplastic relationships at temperatures from 25°C to 5°C. While, PEAA additives having side chain lengths equal or above C16 show Newtonian relationship even at low temperature (5°C) for all tested crude oils. 相似文献
20.
Jian-jun Yang Wan-fen Pu Hu Jia Cheng-dong Yuan Ji-hui Ni Xiao-long Li Ming Yang Hang Jiang 《Journal of Thermal Analysis and Calorimetry》2014,117(2):979-984
The analysis of light crude oil for oxidation reaction experiments is a kind of important technological for evaluating an air injection project in a reservoir. In this study, the paper comprehensively analyzes the variations of Jilin crude oil composition comparing crude oil component’s variations before and after oxidation, and investigates the effluent gas composition and hydrocarbon, analyzes the mechanism of low temperature oxidation reaction (LTO), and rebuilds the light crude oil cracking reaction of intermediate component in a new pattern. In the early stage of the oxidation reaction, firstly, oxygen is captured by forming chemical bond in liquid hydrocarbon. And then oxygen takes part in the free radical chain reaction by forming hyperoxide and decomposes to ketones, aldehydes, alcohols, and so on. Meanwhile, chain scission reaction comes up. Research result shows that the intermediate components (C7–17) of crude oil make great contribution to crude oil cracking. The experimental result shows that Jilin reservoir has the potential of implementing air injection project. 相似文献