Thermal behavior and compatibility study of dihydroxylammonium 3,4-dinitraminofurazan

A large number of nitramino-featured energetic salts have been reported and some of them show promising properties. Among them, the dihydroxylammonium 3,4-dinitraminofurazan (HADNAF) is easy to synthesize and shows high calculated detonation performances and acceptable thermal stability. The non-isothermal kinetics parameters of HADNAF including the apparent activation energy (E) and pre-exponential factor (A) of the exothermic decomposition reaction, and activation entropy (ΔS^≠), activation enthalpy (ΔH^≠), activation Gibbs free energy (ΔG^≠) at T_P0 of the reaction and the critical temperature of thermal explosion (T_b) were obtained by Kissinger’s and Ozawa’s method, respectively. Additionally, the compatibility of HADNAF with other materials (e.g. TNT, RDX, HMX, B, Mg) was tested by DSC method.     

Corrosion inhibition efficiency of linear alkyl benzene derivatives for carbon steel pipelines in 1M HCl

Linear alkyl benzene sulfonic acid (L) and three of its ester derivatives (L1, L2, L3) were prepared, followed by quaternization of these esters (L1Q, L2Q, L3Q). The corrosion inhibition effect on carbon steel in 1 M HCl was studied using weight loss and potentiodynamic polarization measurements. The adsorption of the inhibitors on carbon steel surface obeyed the Langmuir’s adsorption isotherm. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpy (ΔH¹), entropy (ΔS¹) of activation, adsorption–desorption equilibrium constant (K_ads), standard free energy of adsorption (ΔG^o_ads), heat (ΔH^o_ads), and entropy of adsorption (ΔS^o_ads) were calculated to elaborate the corrosion inhibition mechanism.     

Preparation,characterization of RDX/GAP nanocomposites,and study on the thermal decomposition behavior

1, 3, 5-trinitro-1, 3, 5-triazinane/Glycidylazide polymer (RDX/GAP) energetic nanocomposites were fabricated via a facile sol-gel method. Morphologies and structure characterization of RDX/GAP energetic nanocomposites were studied by scanning electron microscopy (SEM), Raman and Fourier-transform infrared spectroscopy (FT-IR). SEM images indicated the sizes of RDX particles in RDX/GAP nanocomposites were in nanoscale. FT-IR spectra of RDX/GAP nanocomposites showed the conjunct characteristics of RDX and GAP, implying RDX particles were trapped in GAP gel matrix. Raman detection revealed the crystal form of RDX maintained original α-form during sol-gel process. The thermal kinetics and thermodynamics of RDX/GAP energetic nanocomposites were investigated by differential thermal analyzer (DTA) under various heating rates (5, 10, 15, and 20°C min^?1). The kinetic and thermodynamic parameters of the energetic nanocomposites, such as activation energy (Ea), activation enthalpy (ΔH^≠), activation entropy (ΔS^≠), and activation Gibbs free energy of (ΔG^≠) were obtained. The activation energies of RDX/GAP nanocomposites were lower than those of raw RDX and GAP-RDX mechanical mixtures, indicating RDX/GAP nanocomposites presented high thermolysis activities. The thermodynamic parameters presented a rising trend when the contents of RDX increase. The critical temperature of thermal explosion (T_b) and the self-accelerating decomposition temperature (T_SADT) based on the activation energy were also obtained.     

Characterization and Thermal Decomposition of Nanometer 2,2′, 4,4′, 6,6′-Hexanitro-Stilbene and 1,3,5-Triamino-2,4,6-Trinitrobenzene Fabricated by a Mechanical Milling Method

Nanometer 2,2?, 4,4?, 6,6?-hexanitro-stilbene (HNS) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) were fabricated on a high-energy ball mill. The particle sizes of nano-HNS and nano-TATB were 98.4 and 57.8 nm, respectively. An SEM analysis was employed to image the micron morphology of nano-explosives. The particle size distribution was calculated by measuring the size of 300 particles in SEM images. XRD, IR, and XPS analyses were used to confirm whether the crystal phase, molecule structure, and surface elements were changed by the milling process. Thermal decomposition of nano-HNS and nano-TATB was investigated by differential scanning calorimetry (DSC) and thermal-infrared spectrometry online (DSC-IR) analyses. Using DSC traces collected from different heating rates, the kinetic and thermodynamic parameters of thermolysis of raw and nano-explosives were calculated (activation energy (E_K), pre-exponential factor (lnA_K), rate constant (k), activation heat (ΔH^≠), activation free energy (ΔG^≠), activation entropy (ΔS^≠), critical temperature of thermal explosion (T_b), and critical heating rate of thermal explosion (dT/dt)_Tb). The results indicated that nano-explosives were of different kinetic and thermodynamic properties from starting explosives. In addition, the gas products for thermal decomposition of nano-HNS and nano-TATB were detected. Although HNS and TATB are both nitro explosives, the decomposition products of the two were different. A mechanism to explain the difference is proposed.     

The influence of sulfur on the structural-dynamic parameters of petroleum systems studied by the NMR technique

A number of crude oils, fuel oils, and asphalts containing sulfur with a concentration in the range of 0.16–4.61 wt % were studied by the nuclear magnetic resonance technique. The NMR relaxation parameters were measured with a 08/PC laboratory NMR relaxometer made in-house according to TU 25-4823764.0031-90 and a computerized portable proton magnetic resonance analyzer. A multiexponential character of the spinecho envelope was revealed for all samples, which was deconvoluted into three exponentials having relaxation times of T _2A, T _2B, and T _2C. The obtained high-resolution NMR spectra of crude oil, fuel oil, and asphalt show that sulfur contributes to the width of all spectral lines. The slope of the T _1A, T _1B, T _1C, T _2A, T _2B, and T _2C plots varies depending on the temperature range of the measurement in all cases, thereby indicating a change in the activation energy E _Ai of molecular motion. All of the activation energies increase with an increase in the sulfur concentration. Over the entire range of measurement temperatures, there is one activation energy for crude oils and two activation energies E _A¹ and E _A² for fuel oils, with the low-temperature activation energies having higher values. An analysis of the asphalt revealed five, not two, activation energies or intervals of constant E _B² values (structurally-dynamically ordered phases of the shells of asphalt structure units).     

The Improvement of the Quality of Raffinate Obtained from Solvent Extraction of Lubricating Oils

Abstract

Vacuum distillates of an Egyptian crude oil were subjected to solvent extraction process applying N-methyl-2-pyrrolidone (NMP) and furfural as dearomatization solvents. The study shows that the extraction solvent together with the temperature and solvent-to-oil ratio have a significant effect on the yield and quality of produced lubricating oils. The optimum temperature for extracting light waxy distillates with NMP is 55°C at the solvent-to-feed ratio 2:1. These conditions are appropriate to remove the major portion of aromatics from the raffinate. The apparent activation energy (Ea), enthalpy (ΔH*), entropy (ΔS*), and free energy of activation (ΔG*) were calculated for the solvent dearomatization process.     

Spectroscopic Studies on Some Crude Oils from The North Western Desert,Egypt

Abstract

A direct method for crude oil evaluation based on spectral techniques is demonstrated in this article. This method is demonstrated for four crude oils from the El-Faras and Raml oil fields in the North Western Desert in Abu Gharadeg Basin, Egypt. The crude oils have been studied by ¹³C nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. Several parameters calculated from the ¹³C NMR and FTIR spectra provide useful information about the maturity of the organic matter in term of relative aliphatic, aromatic, and carbonyl/carboxyl concentrations; aliphatic chain length; and type and degree of substitution of aromatic structures. These spectra techniques may provide valuable information about the aromaticity and diverse functionalities that are important to the thermal history of the crude oil samples. Results showed that the composition of crude oil samples have higher aliphatic compounds than that of the aromatic compounds.     

The effect of cationic surfactant additives on flow properties of crude oil

Pretreatment of the crude oil with flow improver or pour point depressants has received the greatest acceptance due to its simplicity and economy. Three cationic surfactants Bola form based on urea were prepared by quaternization reaction with alkyl dihalides of different chain length (hexayl, decyl-, and dodecyl-dibromide). The prepared compounds (U6, U10, and U12) were evaluated as surface active agents as well as pour point depressant for crude oil compared to monosurfactant (U12a) corresponding to (U12). The surface parameters of each synthesized surfactant were calculated from their surface tension profile including the critical micelle concentration, maximum surface excess (Γ_max), and the minimum surface area (A_min). The free energies of micellization (ΔG°_mic) and adsorption (ΔG°_ads) were also calculated. Its pour point and viscosity decreased significantly after adding surfactants. FTIR studies of crude-surfactant mixture showed remarkable decrease in concentration of viscosity enhancing groups such as alkanes, alcoholic, and acidic groups, indicating the effectiveness of both the surfactants.     

Oil-source correlation and the impact of oil-filling process on geochemical composition of the different states of oils in the Upper Triassic Chang 7 Formation,Ordos basin,China

Five crude oil samples from five wells and 33 oil-containing sandstone reservoir rock samples from six wells of Chang 7 sub-unit were systematically studied to determine hydrocarbons in these oil reservoirs whether are the mixtures of oil components derived from different source rocks or from the same source rock during oil filling process over geological times. Sequential extraction was applied to the oil-containing reservoir rocks to deserve the free and adsorbed oils. The distribution of alkanes, hopanes and steranes and the correlation diagram of Pr/n-C₁₇ versus Ph/n-C₁₈ show that these oil components and crude oils have similar parent materials. And on this basis we compared the thermal maturity of the crude oils, the free oils and adsorbed oils and found that the thermal maturity of these oils is different. The cross plot of C₂₉αα-20S/(20S+20R) versus C₂₉ββ/(αα+ ββ) and the correlation diagram of Pr/n-C₁₇ versus Ph/n-C₁₈ both show that the crude oils have highest thermal maturity, followed by the free oils and then the adsorbed oils. The ratios of ∑C₂₁^?/∑C₂₂⁺ for the crude oils and free oils are greater than the adsorbed oils, indicating the crude oils and free oils have suffered more thermal stress and extensive cracking than that of the adsorbed oils. These geochemical data reveal that hydrocarbons in these oil reservoirs and crude oils were derived from the same source rock with different thermal maturity over geological times.     

A Comprehensive Evaluation of High Viscous Crude Oil from Shuguang No. 1 Zone of Liaohe Oil Field

Abstract

The high viscous crude oil from Shuguang No. 1 zone of Liaohe oil field has the characteristics of high density (ρ ₂₀ = 0.9977 g cm^?3), great viscosity (ν ₁₀₀ = 1223.9 mm² s^?1) and high pour point (48°C), which are similar to those of the residue distillation of general crude oils. It contains no gasoline distillation and the diesel oil fraction yield is just 7.19%. It is often used as fuels after emulsification. But this oil is so vicious that it cannot be atomized uniformly and burned fully. In order to make full use of it, this kind of high viscous crude oil has been evaluated comprehensively and the properties of its various distillations are analyzed respectively. The results indicate that this crude oil contains less wax, but more resins and asphaltene, which belongs to low-sulfur naphthene-base crude oils and it is the suitable material to produce high-quality paving asphalt. Based on its characteristics, the optimum processing scheme is put forward and the high-quality paving asphalt is produced by using the distillation higher than 350°C.     

Synthesis of phthalimide and succinimide copolymers and their evaluation as flow improvers for an Egyptian waxy crude oil

This paper describes the synthesis, characterization and performance evaluation of three phthalimide and three succinimide copolymers of vinyl acetate, styrene and methyl methacrylate as flow improvers for waxy crude oil. The prepared copolymers were named as; (VA)Ph; (St)Ph; (MMA)Ph; (VA)S; (St)S and (MMA)S. These copolymers were characterized by FTIR and ¹H NMR spectroscopy. The molecular weights and nitrogen content of these copolymers were determined by using the GPC technique and the Kjeldhal method, respectively. The rheological properties of crude oil (with and without additives) were studied. From the obtained results, it was remarked that the styrene phthalimide copolymer (St)Ph exhibited the maximum pour point depression (ΔPP_500 ppm = 30). The results of the rheological flow properties showed that the Bingham yield values (τ_β) for crude oil without additives at 15, 27 and 39 °C were 0.286, 0.131 and 0.075 Pa respectively, whereas the τ_β for the treated crude oil by the styrene phthalimide (St)Ph copolymer were 0.021, 0.0164 and 0.0081 Pa at 500 ppm at the same temperatures.     

Kinetics and mechanisms of the catalytic thermal cracking of asphaltenes adsorbed on supported nanoparticles

The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene content. The upgrading and recovery processes of these unconventional oils are typically water and energy intensive, which makes such processes costly and environmentally unfriendly. Nanoparticle catalysts could be used to enhance the upgrading and recovery of heavy oil under both in situ and ex situ conditions. In this study, the effect of the Ni-Pd nanocatalysts supported on fumed silica nanoparticles on post-adsorption catalytic thermal cracking of n-C7 asphaltenes was investigated using a thermogravimetric analyzer coupled with FTIR. The performance of catalytic thermal cracking of n-C7 asphaltenes in the presence of NiO and PdO supported on fumed silica nanoparticles was better than on the fumed silica support alone. For a fixed amount of adsorbed n-C7 asphaltenes (0.2 mg/m2), bimetallic nanoparticles showed better catalytic behavior than monometallic nanoparticles, confirming their synergistic effects. The corrected Ozawa– Flynn–Wall equation (OFW) was used to estimate the effective activation energies of the catalytic process. The mechanism function, kinetic parameters, and transition state thermodynamic functions for the thermal cracking process of n-C7 asphaltenes in the presence and absence of nanoparticles are investigated.     

一种新的原油轻烃分类法——塔里木盆地原油分类及其地化特征

根据Mango提出原油中轻烃成因的假说--稳态催化成因,按“母体”(甲基己烷类)占C7化合物的百分数与两类“子体”(二甲基戊烷类+3-乙基戊烷;1,1和1,3-二甲基环戊烷类)丰度比的关系图,将塔里木盆地不同地区、层位的141个原油分成A、B两大类和四亚类。为了验证分类的有效性和研究影响分类的因素,对各类原油中微量元素、饱和烃的C₁₄⁺色谱、生标组成及其分布规律进行了综合研究。鉴于各类原油具明显的地化特征区别,且在地区、层位上有一定的规律性,证实根据Mango假说提出的新的原油轻烃分类方法在塔里木盆地是有效的,在高熟的油气区更有应用前景。研究成果支持Mango的观点,即影响轻烃分类的主要因素可能是受沉积环境控制的催化剂组成,此外干酪根类型等也可能有一定的影响。     

The Preparation and Characterization of Some Novel Quaternary Iminium Salts Based on Schiff-base as a Corrosion Inhibitor

Abstract

Novel quaternary iminium compounds, namely, N-(4-methoxybenzylidene)-N-benzyldodecyliminium chloride (I_a), N-(4-methoxybenzylidene)-N-benzylhexadecyl iminium chloride (I_b), N-(4-methoxybenzylidene)-N-benzyloctadecyliminium chloride (I_c), and N-benzylidene-N-benzyldodecyliminium chloride, were prepared. The surface properties such as surface and interfacial tension, foaming, and emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration (CMC), maximum surface excess (Γ_max), minimum surface area (A_min), efficiency (PC₂₀), and effectiveness (π_CMC) were calculated. Free energy of micellization (ΔG°_mic) and adsorption (ΔG°_ads) were calculated.     

13C NMR identification in crude oils of hydrocarbons bearing ethyl and n-alkyl substituents on their main chain

Assignment of ¹³C NMR signals of compounds with ethyl, n-propyl, n-butyl, n-amyl, and n-C₆₊ alkyl substituents in different positions of carbon chains in the spectra of saturated hydrocarbon fractions of crude oils and in the spectra of crude oils, taking into account the dependence of chemical shifts on the recording temperature, the concentration of the test solution. and the composition of the object of study, has been proposed. The capabilities of the ¹³C NMR technique as applied to determination of this almost unexplored group of hydrocarbons in crude oils have been discussed.     

The Mild Oxidative Degradation of the Heavy Constituents in Viscous Crude Oils/Oil Sands and Its Prospect in Oil Recovery

Abstract

Viscous crude oils and oil sands are important energy resources, but it is difficult to exploit them due to the dominated heavy constituents such as asphaltenes. In this work, the mild oxidative degradation of the heavy constituents (oxidized by NaIO₄/NaH₂PO₄ and 30% H₂O₂/CH₃COOH) has been carried out. In the viscous oils, more than 45% asphaltenes has been degraded, and the asphaltenes are mainly chemically changed into the resin fractions, which is favorable to the stability of viscous crude oils. After the degradation, the total amount of extractable organic compounds from oil sands has been markedly increased than that of the blank experiment. The experimental results indicate that the mild oxidative degradation of asphaltenes can improve the physicochemical properties of the viscous oils and oil sands, which is particularly in favor of the exploitation of these energy resources.     

Oil-source correlation in Qingdong sag of Bohai Bay basin,China

Geochemical experiments on 11 cores and 14 crude oil/oil sand samples from Qingdong sag have been performed. The oils range from immature to mature and some of the oils suffered biodegradation. The Es₃^l member of the Shahejie Formation (group A) deposits under fresh water. The Es₄^u member (group B) mainly deposits in brackish-saline evaporate environment, generating both immature and mature oils. Results show the nonbiodegraded oils in Es₃^l reservoirs in the north of the sag (group I) come from mature Es₃^l member (group A), while those in Es₄^u reservoirs (group III) come from mature Es₃^l (group A) and Es₄^u (group B₁) members in the north; the less biodegraded oils (group II) in the western slope are the admixture of immature and mature oils of Es₄^u member (group B₂) in the north; immature oils (group V) in the south are from the neighboring low mature Es₄^u member (group B₃), and the most severely biodegraded oils (group IV) in the southern come from Dongying sag, except oils from well QD-8 that have a contribution from Es₄^u member (group B₃) from Qingdong sag.     

Dissolution Properties of Dihydroxylammonium 5,5ʹ-Bistetrazole-1,1ʹ-diolate and Disodium 5,5ʹ-Bistetrazole-1,1ʹ-diolate in Water

The dissolution and thermochemical properties of dihydroxylammonium 5,5?-bistetrazole-1,1?-diolate (TKX-50) and its intermedium disodium 5,5?-bistetrazole-1,1?-diolate ([Na₂(H₂O)₄]BTO) in water at 298.15 K were studied using a C-80 Calvet microcalorimeter. Empirical formulae for the calculation of the molar enthalpies of dissolution (Δ_dissH), relative partial molar enthalpies (Δ_dissH_partial), and relative apparent molar enthalpies (Δ_dissH_apparent) were deduced by the experimental results of the dissolution processes of TKX-50 and [Na₂(H₂O)₄]BTO in water. Finally, the corresponding kinetic equations describing the dissolution processes were dα/dt = 10^?2.95(1 ? α)^0.64 for the dissolution of TKX-50 in water and dα/dt = 10^?2.76(1 ? α)^1.07 for the dissolution of [Na₂(H₂O)₄]BTO in water.     

Petroleum Geochemistry of Lower Indus Basin,Pakistan: II. Oil-oil and Oil-source Rock Correlation

Nine crude oils and eight source rock samples from Cretaceous sequences, Lower Indus Basin have been characterized by means of diagnostic biomarker parameters in order to establish genetic liaison among them. The biomarker geochemistry indicators such as relative distribution of C₂₇-C₂₈-C₂₉ ααα-20R steranes, C₁₉ and C₂₃ tricyclic terpanes (TT), C₂₄ tetracyclic terpanes (TeT), hopanes distribution, steranes/hopanes ratio, presence of unidentified compound X (C₃₀ pentacyclic triterpane), and pristane (Pr) to phytane (Ph) ratio suggest that the crude oils contain predominantly terrigenous organic matter (OM). Based on these data, the analyzed crude oils from the Lower Indus Basin are genetically associated and could be classified into a single group. Geochemical correlation studies of crude oils and source rock sediments indicate that Lower Goru shales and Sembar could be the probable source rocks for the petroleum generated from Cretaceous strata, Lower Indus Basin, Pakistan.     

Correlation between main structural group parameters of crude oils of the Volga–Urals oil and gas basin by <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR data

In Volga?Urals crude oils, an increase in the aromatics content is characterized by a rapid increase in the relative amount of polysubstituted aromatic rings and a generally lower proportion of bi- and polycyclic aromatics, unlike the case of Western Siberia oils. The difference between the oil and gas basins is most probably due to the special features of the source organic matter of the oils. The regional features of the Volga?Urals oils are a relatively weak relationship between the concentrations of mono- and bi- + polycyclic aromatics and a relatively close relation of Σn-Alk to typically uninformative parameter Hβ, which indicate a high uniformity of the composition of saturated cyclic compounds and moieties of hybrid naphthenoaromatic components. In addition, the assumption that (H/C)_ar/(H/C)_al = const does not hold for Volga?Urals oils. However, the relationships between the main parameters describing total aromaticity (primarily, C_ar, H_ar) and n-alkyl structures (primarily, Σn-Alk) are identical for oils from both the basins. The total number of relationships that can be universal for oils from different oil-and-gas basins is fifteen. To estimate C_ar from ¹H NMR data for Volga?Urals crude oils, a linear dependence on the two variables H_ar and H_α should be used. The expressions obtained to relate the structural-group parameters have made it possible to reveal a number of oils that stands out among the others.