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 Magnesium Hydride on the Thermal Decomposition Properties of Nitrocellulose

Magnesium hydride is a kind of attractive hydrogen storage material. In this article, the thermal decomposition characteristic of the pure nitrocellulose and the mixture of nitrocellulose with 5% MgH₂ was investigated using an accelerating rate calorimeter. The kinetic parameters such as activation energy, E_a; preexponential factor, A; and self-accelerating decomposition temperature, T_SADT, were also calculated. We easily showed that the decomposition reaction could be accelerated by adding MgH₂, which indicated that MgH₂ has an obvious catalytic influence on the decomposition of nitrocellulose. On the other hand, the calculated values of E_a and T_SADT showed a decrease in thermal sensitivity with the addition of MgH₂. These results were in accordance with our objectives. Therefore, MgH₂ is very likely to be an important additive in propellants.     

One-Pot Synthesis,Crystal Structure,and Thermal Decomposition Behavior of 1,1ʹ-Diamino-4,4ʹ,5,5ʹ-Tetranitro-2,2ʹ-Biimidazole

1,1?-Diamino-4,4?,5,5?-tetranitro-2,2?-biimidazole (DATNBI) was synthesized, by employing one-pot facile method, from 4,4?,5,5?-tetranitro-2,2?-biimidazole. The crystal structure was determined by X-ray diffraction for the first time. DATNBI crystallized in monoclinic system P2₁/c, with a crystal density of 1.934 g cm^?3 at 293(2) K and 2.019 g cm^?3 at 130(2) K, respectively. Its crystal parameters at 293 K are a = 4.8833(15) Å, b = 6.960(2) Å, c = 6.928(4) Å, α = γ = 90°, β = 93.418(6)°, V = 591.1(3) ?³, Z = 2, μ = 0.178 mm^?1, and F(000) = 348. The thermal stability and non-isothermal kinetics of DATNBI were studied by differential scanning calorimeter (DSC) with heating rates of 5, 10, 15, and 20 K min^?1. The apparent activation energy (E_a) at the first decomposition peak calculated by Kissinger, Ozawa, and Starink equations were 85.50, 89.67, and 86.10 kJ mol^?1, respectively. For the second peak, these were 116.49, 119.82, and 117.45 kJ mol^?1, respectively, with individual pre-exponential factors lnA = 18.40 s^?1 and lnA = 25.11 s^?1. The thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR) analysis of thermal decomposition products reveals that the main decomposition gas products are H₂O, N₂O, CO₂, and NO₂. Based on the new crystalline densities, the detonation velocity and pressure predicted by EXPLO5 are 9062 m s^?1 and 36.4 GPa, respectively.     

Studies on Triple Base Gun Propellant Based on Two Energetic Azido Esters

Triple base propellant is the workhorse propellant because it possesses several advantages like reduced flash, flame temperature, and erosion of the barrel as compared to double and single base propellant. Hence, efforts are going on worldwide to increase its performance by increasing its energy using energetic plasticizers and binders. In the present article, nonenergetic plasticizer dibutyl phthalate (DBP) is replaced by two energetic azido ester plasticizers, tris(azido acetoxy methyl) propane (TAAMP) and bis(azido acetoxy) bis(azido methyl) propane (BABAMP), in triple base composition and their different properties are studied.

Experimental closed vessel (CV) results (loading density 0.2 g/cm³) clearly indicate that the triple base composition with 2% DBP has force constant 1018 J/g, which is increased to 1026 and 1030 J/g on replacement of DBP by 1 and 2% TAAMP, respectively. Mechanical properties of propellant compositions containing 1 and 2% TAAMP (compression strength 279 and 291 kg_f/cm², percentage compression 11.2 and 10.5, respectively) are also better than those of composition containing DBP (compression strength 275 kg_f/cm² and 10.3% compression). Similarly, 1 and 2% replacement of DBP by BABAMP shows further rise in energy (1032 J/g, 1038 J/g respectively) than that of compositions containing 1 and 2% TAAMP. These two compositions also exhibit better mechanical properties (compression strength 311.2 and 312.3 kg_f/cm², % compression 11.0 and 10.5, respectively) than compositions containing 1 and 2% TAAMP. The differential thermal analysis (DTA) results brought out the fact that the compositions containing energetic plasticizers revealed maximum decomposition temperature in the range of 172–174°C which is close to DBP plasticized triple base gun propellants (174°C). The energetic plasticized propellant compositions of both (TAAMP and BABAMP) showed sensitivity data in the range of (H₅₀ 19 to 22 cm, F of I 25 to 29 and friction insensitivity 19.2 kg) acceptable limit for gun propellant.     

Novel high-energy ionic molecules deriving from new monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties

ABSTRACT

In recent years, the exploration of a practical strategy for novel energetic molecules with high energy and low sensitivity is very desirable but highly challenging. Novel ionic energetic molecules have attracted much attention in this area due to their prominent advantages including low sensitivities, high thermal stability, and excellent energy performances. Herein, five different ionic energetic molecules based on new monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties with enhanced oxygen balance have been synthesized, characterized and evaluated as potential high-energy materials. Thermal stability, sensitivities and energy output test were measured and studied in detail. The heats of formation and energetic parameters were calculated by using Gaussian 09 suite of programs and EXPLO 5 code. The results suggest that all as-prepared new molecules exhibit good thermal stability with high decomposition temperature (3, 231°C; 5, 160°C; 6, 185°C; 7, 180°C; 8, 213°C), and relative low sensitivity (IS > 20 J, FS = 324 N). Inheriting the significant oxygen content of monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties, they also possess good energy properties (v _D = 8238 ~ 9208 m s^?1, P = 26.8 ~ 36.7 GPa, V _o = 481.8 ~ 959.4 L kg^?1), which make them competitive high-energy materials.     

An Experimental Study of the Explosion Parameters of Vapor-Liquid Mixtures of Nitroethane/Air

The explosion hazards characterizing vapor-liquid mixtures (mists) are commonly overlooked, resulting in significant damage within processing industries that use these mixtures. This article presents new experimental data that enable the quantitative evaluation of the effects of vapor-liquid mixtures of nitroethane/air on various explosion parameters. A series of experiments was conducted as follows: First, at mean Sauter mean diameter (SMD, D₃₂=6V_p/A_p, where A_p and V_p are the surface area and volume of the particle, respectively) values of 19.33 and 33.75 μm, two sets of vapor-liquid mixtures of nitroethane/air at various concentrations were obtained. Subsequently, experiments were conducted, and the explosion pressure and temperature of the two sets of vapor-liquid mixtures of nitroethane/air at various concentrations were analyzed. The flame temperatures and explosion pressures, maximum rate of pressure rise [dP/dt]_max, maximum rate of temperature rise [dT/dt]_max, flame propagation delay time, and lower explosion limit (LEL) were analyzed. At both mean SMD values (19.64 and 34.40 μm), the peak pressure of the vapor-liquid mixtures of nitroethane/air increased as the total concentration was increased, within the flammable range. However, the total concentration of the maximum peak temperature at a mean SMD of 19.64 μm was less than that at a mean SMD of 34.40 μm, with values of 418.38 and 631.20 g m^?3, respectively. For a similar concentration of the gaseous-phase or vapor-liquid mixture of nitroethane/air, the [dP/dt]_max of the vapor-liquid mixtures of nitroethane/air was significantly larger than that of the gaseous-phase nitroethane/air mixtures.     

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.     

Kinetics of desulfurization by electrochemical oxidation in an emulsifying electrolyte

Diesel with S content 624.4 µg/g was directly used, and a constant current of 500 mA was proposed in this work. Emulsification as an enhancement method was used to enhance the interphase mass transfer. After emulsifying electrochemical oxidation–extraction, the sulfur content of diesel decreased to 8.1 µg/g and the desulfurization efficiency reached 98.71 %. On comparingwith the non-emulsifying electrochemical oxidation–extraction, it has a highly efficient deep desulfurization.

The analysis also found that the effect of emulsion and non-emulsion extraction desulfurization process on electrochemical oxidation has great difference under the same operating conditions, and parameters such as the order, reaction rate and activation energy of the two kinds of oxidation desulfurization reaction were studied. The results showed the oxidative desulfurization reaction is the first reaction. When the temperature reached T₂, the oxidation rate constant of the emulsion/non-emulsion system was 0.0199 min^?1 and 0.0179 min^?1, respectively. When the temperature reached T₁, the oxidation rate constant of the emulsion/non-emulsion system was 0.0375 min^?1 and 0.0346 min^?1, respectively. According to Arrhenius' law, the apparent activation energy of sulfur compounds in the raw oil is E_a (emulsion) = 6.9783 kJ/mol and E_a (non-emulsion) = 9.1826 kJ/mol, respectively.     

POLLEN TRANSLUCENCY AS A THERMAL MATURATION INDICATOR

Using an inversion technique, we show that pollen translucency with depth can be used as a quantitative tool to estimate the thermal history of sedimentary sequences. The overall trend of translucency is a decrease with increasing depth. In this study, three wells in southern Louisiana were examined, each having Carya (a pollen genus including present-day Pecans and Hickories) translucency measurements with depth, and one of the wells containing measurements of vitrinite reflectance with depth. High sedimentation rates (>250 ft/MM yrs of shale) require the use of a fluid flow/compaction burial history program linked with the Carya inversion algorithm. Thermal history is estimated by the interaction of a heat flux taken to be linear in time, and a time-temperature integral for the inversion of Carya translucency. The former involves β, a linear heat-flux coefficient to be determined, while the latter involves two previously unknown constants: T_C, a critical temperature, below which the translucency is stable (no carbonization), and T_D, a scaling constant, roughly analogous to a doubling temperature. T_D and T_c are chemical constants, and should be consistent in the three wells, while β should be consistent when determined independently by vitrinite reflectance and Carya translucency inversions. Grid searches for an acceptable solution in T_C vs. T_D vs. βspace were carried out for each of the three wells to determine the best T_D T_C and β for each well. A goodness-of-fit criterion, contoured in T_D vs. T_C vs. βspace, defines a volume of solutions within fixed error limits. Estimates of T_D= 75 ± 30°K and T_C= 290 + 20°K, for the genus Carya, are consistent for all of the wells. Acceptable β ranges, determined by the Carya inversion, overlap for the neighbouring wells. and the ranges are also consistent with β determined by the independent inversion of vitrinite reflectance in one of the wells. We conclude that Carya translucency can be used as a quantitative thermal indicator. Application of the inverse method to translucency measurements on other palynomorphs having longer. or different, age ranges than the Eocene-Recent lifetime for Carya is recommended.     

Combustion Characteristics and Propulsive Performance of Boron/Ammonium Perchlorate Mixtures in Microtubes

A microthruster is used for the operation tracking and posture control of microsatellites. In this work, the combustion characteristics and propulsive performance of a boron/ammonium perchlorate (B/AP) propellant mixture for a microthruster were investigated. Amorphous B and AP were used in different mass ratios to prepare the propellant samples. A laser-ignition solid micropropulsion test system was set up, and a differential scanning calorimeter was used. The solid combustion products of the samples with good performance were collected. Microstructural and component analyses of the combustion products were performed. Various performance parameters, including the combustion temperature, combustion velocity, spectral intensity, ignition delay time, thrust, specific impulse, density specific impulse, and heat flow, changed with the fuel–oxidant ratio. The optimal fuel–oxidant mass ratio of the propellant samples was 40%, with a density specific impulse of 0.474 kg/m²?s and a maximum heat flow of 4.4913 mW/mg. Analysis of the combustion products revealed that the clearance between particles significantly diminished after combustion. During combustion, the AP completely decomposed, and a large amount of H₃BO₃, B₂O₃, and HBO₂ was generated.     

Kinetics of thermal degradation of a Japanese oil sand

Thermal degradation characteristics of a Japanese oil sand at different heating rates (10, 20, and 30 °C/min), and 30 ml/min air flow rate have been investigated. The kinetic parameters have been calculated based on three stages of weight loss and/or the conversion of the sample. These include, stage 1 (SI): volatilization of moisture content and the light hydrocarbon (20–227 °C), stage 2 (SII): combustion of heavy hydrocarbon (227–527 °C), and stage 3 (SIII): oxidative decomposition of carbonaceous organic matter (502–877 °C). The results showed that the rate of change of the oil sand conversion with time $\left(\frac{d\alpha }{\mathit{dt}}\right)$ was affected by the heating rate. The time taken by the system to reach 0.99 conversion was observed as 85, 50, and 35 min at the heating rates of 10, 20, and 30 °C/min, respectively. The frequency factor, A, at SI was between 0.09 and 0.54 min^?1, while the activation energy, E_a, was 11.2–12.5 KJmol^?1 (the percentage weight loss, W_t, was 0–3.6 %w/w; and the conversion, α, was 0–0.2.). At SII, the values of A and E_a were 2.1–5.5 min^?1 and 17.6–19 KJmol^?1, respectively (W_t = 3.1–15.88 %w/w; α = 0.17–0.86.). The value of A at SIII was 5.5E11–1.1E13 min^?1, while E_a was 160–200 KJmol^?1 (W_t = 15.33–17.99 %w/w; and α = 0.84–0.99).     

Synthesis,characterization, and thermal analysis of a new energetic salt based on 1ʹ-hydroxy-1H,1ʹH-5,5ʹ-bitetrazol-1-olate

4-Amino-1,2,4-triazolium 1?-hydroxy-1H,1?H-5,5?-bitetrazol-1-olate (ATHBTO) was synthesized by reacting 4-amino-1,2,4-triazole (AT) and 1H,1′H-5,5′-bistetrazole-1,1′-diolate dihydrate (H₂BTO·2H₂O). Its crystal structure was characterized through single-crystal X-ray diffraction. Meanwhile, FTIR, ¹H NMR, ¹³C NMR, and elemental analysis were also introduced to analyze its composition. The thermal stability was investigated by differential scanning calorimetry, thermogravimetric analysis, and thermogravimetric tandem infrared spectrum. Results indicated that ATHBTO exhibited excellent resistance to thermal decompositions reaching 511.4 K and had a 64.6% mass loss between 475.7 and 552.3 K. The kinetics parameters were calculated by Kissinger’s method and Ozawa–Doyle’s method. Moreover, according to the Kamlet–Jacobs formula, the calculated detonation velocity and detonation pressure of ATHBTO attained 8218 m/s and 28.69 GPa, respectively.     

Ammonium perchlorate-based molecular perovskite energetic materials: preparation,characterization, and thermal catalysis performance with MoS2

ABSTRACT

In this study, ammonium perchlorate (AP)-based molecular perovskite structural high-energetic materials (H₂dabco)[NH₄(ClO₄)₃] (DAP) were fabricated and their catalytic performance upon the addition of MoS₂ nanosheets was investigated. The DAP samples were succesfully prepared via a self-assembly reaction and their morphology and structure were characterized via scanning electron microscopy, X-ray diffractometry, and Fourier transform infrared spectroscopy. The thermal decomposition performance of a pure DAP sample and of a mixture of DAP with MoS₂ nanosheets were analyzed via differential scanning calorimetry. The results show that DAP has a high thermal stability at its initial decomposition temperature of 319.8°C, and that its apparent decomposition heat measures 4199 J/g. This value is higher than for AP (829.7 J/g). Furthermore, the thermal decomposition peak temperature of DAP upon the addition of 1 wt% and 3 wt% MoS₂ nanosheets decreases from 394.4°C to 343.3°C and 328.8°C, respectively. The investigation of the catalysis thermal performance of DAP may foster its practical application in composite propellant.     

Study of Different Al/Mg Powders in Hydroreactive Fuel Propellant Used for Water Ramjet

Experiments were conducted to study the effect of magnesium–aluminum alloy on the combustion performance of hydroreactive fuel propellants. The raw metal powders added to the propellants were ball-milled magnesium–50% aluminum alloy (m-AM), magnesium–50% aluminum alloy (AM), and Al and magnesium (Mg) powders, which were characterized using scanning electron microscopy, X-ray diffraction (XRD), and simultaneous thermogravimetric analysis (TGA). A high-pressure combustor and a metal/steam reactor were used to simulate the two-stage combustion of hydroreactive propellants used for a water ramjet. The combustion performance of the metal powders in propellant was studied experimentally, and the efficiency of the Al reaction in the propellants during the two-stage combustion was calculated. TGA traces in air indicated that the oxidation onset temperature of AM powders is much lower than for both Mg and Al powders. The XRD patterns for the AM and m-AM alloys exhibited Al₁₂Mg₁₇ diffraction peaks. The hydroreactive fuel propellant systems with added m-AM powder exhibited good performance in terms of burning rate, combustion heat, and the Al reaction efficiency, which was better than that for the propellants containing AM, Mg, and Al powders. At the pressure studied (3.0 MPa), the burning rate of the m-AM-containing propellant was found to be 15 mm s^?1, and the heat of primary combustion was 6,878.1 kJ kg^?1.     

Preparation and Characterization of the Solid Spherical HMX/F2602 by the Suspension Spray-Drying Method

Solid spherical octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine/fluororubber2602 (HMX/F₂₆₀₂) was prepared by the suspension spray-drying method as follows: firstly, thinning octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) was obtained by a solvent–anti-solvent method. Secondly, thinning HMX suspended in ethyl acetate solvent in a solution of a binder—F₂₆₀₂—was made into a suspension. Finally, the samples were prepared by spray drying. The samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), and its thermal stability as well as mechanical and spark sensitivities were measured. The results of SEM showed that the grain of HMX/F₂₆₀₂ was solid spherical and the particle distribution was homogeneous. The results of XPS indicated that F₂₆₀₂ can be successfully coated on the surface of HMX crystals. Compared to raw HMX, th characteristic drop height was increased from 19.60 to 40.37 cm, an increase of 79.10%. The friction sensitivities of HMX reduced from 100 to 28% and the spark sensitivity of HMX/F₂₆₀₂ increased. The critical explosion temperatures of raw HMX and HMX/F₂₆₀₂ were 275.43 and 274.30°C, respectively. The amount of gas evolution of raw HMX and HMX/F₂₆₀₂ was 0.15 and 0.12 ml·(5 g)^?1, respectively. The results of DSC and vacuum stability tests (VSTs) indicate that the thermal stability of HMX/F₂₆₀₂ was equal to that of raw HMX and HMX and F₂₆₀₂ had good compatibility.     

Investigation on the Thermal Expansion of Four Polymorphs of Crystalline CL-20

The thermal expansion behaviors of α-CL-20 · 1/2H₂O, anhydrous α-, β-, ε-, and γ-CL-20 crystals have been investigated by means of variable-temperature X-ray powder diffraction (XRD) together with Rietveld refinement. The results show that hexanitrohexaazaisowurtane (CL-20) with four polymorphs exhibits linear thermal expansion. The ε phase performs approximately isotropic expansion in the temperature range of 30 to 130°C, but α, β, and γ phases exhibit anisotropic expansion in the temperature ranges of 30 to 130°C, 30 to 120°C, and 30 to 180°C, respectively. The different expansion behaviors are due to the different structures of the four polymorphs. The different thermal expansion behaviors of α-CL-20 · 1/2H₂O and anhydrous α are revealed in this work. The a-axis expansion of α-CL-20 · 1/2H₂O exhibits a switch from positive thermal expansion (PTE) to negative thermal expansion (NTE) at 90°C, whereas the a-axis of anhydrous α is resilient to PTE. The cause is the loss of the structural water. Moreover, it is easily found that the b-axis of the γ phase shows a constriction that may be attributed to the distortion of the six-membered ring.     

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.     

Enhanced heavy oil recovery (SAGD), coinjection of steam and solvent,reduction of CEOR and CSOR

The effect of coinjection of hydrocarbon solvents (C₄, C₅, C₆, C₇, and C₈), with steam at low pressure, on heavy oil recovery is addressed. It is concluded that the coinjection of solvents reduced cumulative steam oil ratio and the lighter solvents performed better in reducing cumulative net energy oil ratio (CEOR, GJ/m³). The work illustrated that C₆ was the best-performing solvent with respect to oil recovery (EOR) at 20 wt%, CEOR with an optimum of 30 wt%. An explanation on the reason for the highest EOR at 20 wt% is given. The coinjection with CO₂ has also been addressed here with different schemes.