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1.
The conclusion has been drawn that the active catalytic materials are of high molecular weight and not readily volatile at 200° C. and 3–5 mm. Hg pressure. This conclusion has beententatively checked by the use of a synthetic product.  相似文献   

2.
The flow patterns and pressure gradient of immiscible liquids are still subject of immense research interest. This is partly because fluids with different properties exhibit different flow behaviours in different pipe's configurations under different operating conditions. In this study, a combination of oil–water properties (σ = 20.1 mN/m) not previously reported was used in a 25.4 mm acrylic pipe. Experimental data of flow patterns, pressure gradient and phase inversion in horizontal oil–water flow are presented and analyzed together with comprehensive comments. The effect of oil viscosity on flow structure was assessed by comparing the present work data with those of Angeli and Hewitt (2000) and Raj et al. (2005). The comparison revealed several important findings. For example, the water velocity required to initiate the transition to non-stratified flow at low oil velocities increased as the oil viscosity increased while it decreased at higher oil velocities. The formation of bubbly and annular flows and the extent of dual continuous region were found to increase as the oil–water viscosity ratio increased. Dispersed oil in water appeared earlier when oil viscosity decreased.  相似文献   

3.
4.
Here, superhydrophobic cuprous oxide(Cu_2O) with hierarchical micro/nanosized structures was synthesized via spray-assisted layer by layer assembling. The as-prepared superhydrophobic meshes with high contact angle(159.6°) and low sliding angle(1°) are covered with Cu_2O ‘‘coral reef"-like micro/nanosized structures. Interestingly, the superhydrophobic mesh surfaces became superhydrophilic again due to the oxidization of Cu_2O to CuO by annealing at a higher temperature(300 ℃). And the superhydrophobic properties would be recovered by heating at 120 ℃. Furthermore, the superwetting meshes were applied to design a miniature device to separate light or heavy oil from the water–oil mixtures with excellent separation efficiency. These superwetting surfaces by simultaneously spray-assisted layer by layer assembling technique show the potential application in universal oil–water separation.  相似文献   

5.
To permit expansion of the resource base and utilize industrial waste, coal–water–oil fuels may be prepared on the basis of coke and semicoke, as well as common petroleum derivatives (fuel oil and spent compressor, turbine, and transformer oils). The minimal oxidant temperature corresponding to stable ignition of coal–water–oil slurries is established. Typical variation in fuel temperature in the course of reaction is determined, as well as the delay time of ignition and the total combustion time for individual droplets of such fuel suspensions. For droplets of initial size 0.5–1.5 mm, the influence of the various factors (droplet size, oxidant temperature, and concentration of the components) on the threshold (minimum) temperature and inertia of ignition is studied. It is shown that stable ignition of coke and semicoke in such fuel is possible at moderate oxidant temperatures: 700–1000 K.  相似文献   

6.
Oil spills and chemical leakages have caused severe environmental problems. Physical absorption of the spilled oils and chemical reagents by absorbing materials is an efficient and economical approach to solve these problems. Herein, we have prepared a porous thermoplastic polyurethane (TPU) sponge by combining the thermally induced phase separation method with the selective dissolution of water-soluble PEG components. The selective removal of PEG components from the walls of TPU sponges could increase the intensities of free volume holes and surface areas of TPU sponges. The content of free volume holes and surface areas of TPU sponge reached its maximum with the TPU/PEG ratio of 1:1. The increased roughness could improve the absorption capacities of TPU sponges for various oils/organic solvents. Moreover, due to its excellent compressibility, this TPU sponge could be reused 20 times with little loss of saturated absorption capacity. In addition, this TPU sponge exhibited excellent separation ability for the toluene from the toluene/water mixture and emulsion. In all, we have developed a facile method to prepare TPU sponge absorbent with excellent absorption performance, which holds great potential in the application of large-scale oil/water separation.  相似文献   

7.
A wire-mesh sensor has been employed to study air/water and air/silicone oil two-phase flow in a vertical pipe of 67 mm diameter and 6 m length. The sensor was operated with a conductivity-measuring electronics for air/water flow and a permittivity-measuring one for air/silicone oil flow. The experimental setup enabled a direct comparison of both two-phase flow types for the given pipe geometry and volumetric flow rates of the flow constituents. The data have been interrogated at a number of levels. The time series of cross-sectionally averaged void fraction was used to determine characteristics in amplitude and frequency space. In a more three-dimensional examination, radial gas volume fraction profiles and bubble size distributions were processed from the wire-mesh sensor data and compared for both flow types. Information from time series and bubble size distribution data was used to identify flow patterns for each of the flow rates studied.  相似文献   

8.
As the coal–oil–water slurry is gaining importance in place of fuel oil, a better understanding of handling characteristics is in demand. Therefore, experimental investigations have been carried out to investigate the rheological properties of coal–oil–water suspension containing coal particles of different sizes. Different coal stocks with average particle sizes of 108 μm, 75.7 μm and 62.9 μm have been used. The concentration of solid for the experiment varies from 10% to 50% by weight. All experiments have been carried out in a cup and bob type coaxial cylindrical viscometer. Newtonian, shear thinning and shear thickening behavior of suspension has been observed depending on component content and operating conditions. Study with different particle sizes shows that it is possible to achieve an optimum particle size for better handling of such suspension. A generalized correlation has been developed to predict the apparent viscosity of coal–oil–water suspension incorporating the coal concentration, oil concentration, torque and particle diameter. The experimental data are in well agreement with proposed correlation.  相似文献   

9.
O.J. Alamu  M.A. Waheed  S.O. Jekayinfa 《Fuel》2008,87(8-9):1529-1533
The finite nature of fossil fuel necessitates consideration of alternative fuel from renewable sources. Palm kernel oil (PKO) has been identified as a renewable resource from which biodiesel can be produced. The effect of ethanol–PKO ratio on PKO biodiesel yield was studied with a view to obtaining optimal feedstock ratio. Experiments were conducted for ethanol–PKO ratios 0.1, 0.125, 0.15, 0.175, 0.2, 0.225 and 0.25 under transesterification conditions of 60 °C temperature, 120 min reaction time and 1.0% KOH catalyst concentration. Results obtained gave 29.5%, 54%, 75%, 89%, 96%, 93.5% and 87.2% average PKO biodiesel yield for the respective feedstock ratios. This shows increase in biodiesel yield with ethanol–PKO ratio up to 0.2. Standard fuel test results of the PKO biodiesel are within biodiesel specifications.  相似文献   

10.
11.
Hong-yan Zeng  Zhen Feng  Xin Deng  Yu-qin Li 《Fuel》2008,87(13-14):3071-3076
Mg–Al hydrotalcites with different Mg/Al molar ratios were prepared and characterized by powder X-ray diffraction (XRD), Fourier-transform infrared spectra (FTIR), thermogravimetric apparatus and differential thermal analysis (TGA-DTA) and scanning electron micrograph (SEM). It was confirmed by XRD that the materials had hydrotalcite structure. The hydrotalcite catalyst calcined at 773 K with Mg/Al molar ratio of 3.0 exhibited the highest catalytic activity in the transesterification. In addition, a study for optimizing the transesterification reaction conditions such as molar ratio of the methanol to oil, the reaction temperature, the reaction time, the stirring speed and the amount of catalyst, was performed. The optimized parameters, 6:1 methanol/oil molar ratio with 1.5% catalyst (w/w of oil) reacted under stirring speed 300 rpm at 65 °C for 4 h reaction, gave a maximum ester conversion of 90.5%. Moreover, the solid catalyst could be easily separated and possibly reused.  相似文献   

12.
An experimental study of a new vane-type pipe separator (VTPS) was conducted for the possible application in the well-bore for oil–water separation and reinjection. Results by using particle image velocimetry (PIV) reveal a better flow field distribution for oil–water separation, which is formed in VTPS than that in hydrocyclone. The effects of split ratio, the oil content, guide vanes’ installation and number of guide vanes on oil–water separation performance have been investigated experimentally. Compared to a traditional single hydrocyclone, VTPS shows a good separation performance as the water content at the inlet of VTPS reaches 79.9%, the oil content at the water-rich outlet is about 400 ppm while the split is near 0.70. These results are helpful to provide a possibly new design for downhole oil–water separation.  相似文献   

13.
Organic–inorganic hybrid coating based on methacrylated/phosphorylated epoxidized soybean oil were obtained by combining photopolymerization and sol–gel process. A series of novel methacrylated and phosphorylated epoxidized soybean oil/silica coating materials were prepared from tetraethoxysilane (TEOS), and acrylated soybean oil via sol–gel technique. Acrylated epoxidized soybean oil (AESO) is obtained by reacting epoxidized soybean oil (ESO) with methacrylic acid and vinyl phosphonic acid. The characterization of AESO was performed by NMR and IR spectroscopy.  相似文献   

14.
Urea–siloxane hybrid coatings were prepared by the sol–gel method from a dipodal diurea silane and methyltriethoxysilane. The coatings combine corrosion protection and scratch and solvent resistance in one layer and enable the incorporation of polydimethylsiloxane (PDMS) to achieve repellent properties. PDMS of different molecular weights were investigated with a molecular weight of 2000–3500 g/mol providing a repellent surface with the best durability. The coating was applied on plate heat exchangers mounted on North Sea oil platforms to prevent crude-oil derived fouling. While the uncoated heat exchangers get clogged by waxy substances and require costly maintenance in regular intervals, the coated heat exchanger significantly prolongs the service interval by at least a factor of 3.  相似文献   

15.
The mineral species in soils vary in a wide variety of places,thus resulting in the petroleumcontaminated soil(PCS) with complex characters.Thus,the research on the effect of mineral species on oil-soil interactions in PCS takes on a critical significance.In this study,the desorption and adsorption behaviors of aromatic hydrocarbons(Ar) on two minerals surfaces were examined.Meanwhile,the interfacial forces between minerals and Ar were studied and the sources of these forces were analyzed.Moreov...  相似文献   

16.
The effect of addition of a varying concentration of a drying catalyst (cobalt salt as primary drier) and a combination of catalysts such as cobalt, zirconium (secondary drier) and calcium (auxiliary drier) in a fixed concentration (1%) to a 50:20:30 compositions of 87% conjugated linseed oil, styrene (ST), and divinylbenzene (DVB) has been studied by characterizing the resulting polymers from thermal polymerization with various techniques such as soxhlet extraction, 1H NMR (1H nuclear magnetic resonance) spectroscopy, dynamic mechanical analysis (DMA), mechanical and thermogravimetric analysis. The thermal polymerization is performed in the temperature range of 85–160 °C. By soxhlet extraction, it is observed that the polymers contain approximately 64–77% crosslinked materials and the crosslinked insoluble fraction increases with an increase in cobalt catalyst concentration. For fixed concentration (1%) of catalysts, the insoluble fraction from the soxhlet extraction is maximum for the cobalt–zirconium mixture and minimum for the cobalt–calcium mixture. The micro-composition of these polymers obtained from the 1H NMR spectroscopy indicates that the crosslinked materials are composed of both soft oily and hard aromatic phases. The polymers with varying cobalt concentrations up to 0.6 wt% exhibit two separate glass transition temperatures, indicating the presence of two separate phases, one soft rubbery phase with sharp glass transition temperature of −50 °C and a hard brittle plastic phase of broadened glass transition temperature of 70–120 °C. On the other hand, instead of sharp peaks, the polymers with 0.8 and 1.0% cobalt salts exhibit two humps and a distinct peak in between the humps in the tan δ plots, indicating the presence of an additional phase comprised of a copolymer of linseed oil–styrene and DVB. For fixed concentration (1%) of catalysts, the cobalt–calcium combination follows the similar trend in the tan δ as that for the polymers with 0.8–1.0% cobalt whereas other combinations exhibit two phases. These polymers possess crosslink densities of 0.63–0.91 × 104 mol/m3 and compressive strengths of 2.0–26.6 MPa. The catalyzed polymers are thermally stable below 300 °C and exhibit a major thermal degradation with a maximum degradation of 82–88% at a temperature of 500 °C.  相似文献   

17.
Olive mill waste water (OMWW) contains high concentrations of phenols that are responsible for the high toxicity of the effluent. A one step precipitation process of OMWW by cold methanol yielded a polymeric organic precipitate (polymerin) and a supernatant (OMWW-S) rich in phenols, which were further concentrated in an ethyl acetate extract (OMWW-E). This extract was comparatively adsorbed on: i) a layered double hydroxide of magnesium and aluminium (LDH); ii) the LDH after calcination at 450 °C (LDH-450); iii) a hydroxyaluminium–iron-co-precipitate (HyAlFe); and iv) a hydroxy-aluminium–iron–montmorillonite complex (HyAlFe-Mt). Adsorption behaviour and kinetics of phenols with these materials were investigated. The Langmuir model better described adsorption (R2 > 0.97) in comparison to the Freundlich model (R2 > 0.89). Phenols were sorbed according to the following order: LDH-450 > LDH > HyAlFe > HyAlFe-Mt. Phenol adsorption on LDH matrices was strong, since desorption with simulated soil solution under dynamic conditions never exceeded 20%. Cyclic adsorption conducted with LDH-450 removed most phenols, ~ 94% from OMWW-E, consequently reducing its phytotoxicity. The study evidenced that calcined LDH represented an effective remediation process for OMWW.  相似文献   

18.
Ways of developing and modernizing Russian oil refineries are considered on the basis of an analysis of the presentations of Russian and foreign companies at the 10th Russian and CIS Refining Technology Conference (RRTC) held by Euro Petroleum Consultants in Moscow on September 23–24, 2010. It is shown that the main trends in the development of the Russian oil refining industry with the purpose of overcoming the current economic crisis are the rational use of production facilities, the modernization of existing plants to increase the depth of processing and the profitability of production, satisfying the growing demand for motor fuels (especially diesel) and improving their quality to meet the parameters of eurostandards, increasing the conversion of the processing of oil at oil refineries, reducing the consumption of energy, and improving the process control and optimization systems at existing plants to increase their efficiency and minimize the environmental risks in operating plants. The development of hydrogenation processes that allow the synthesis of high-quality products from cheap sour crude oil or the qualified preparation of raw materials for the process of catalytic cracking must now become the main direction of oil refining in Russia and CIS countries. Oil residue processing technologies (e.g., hydrogenation processes, catalytic cracking, new and improved catalysts for hydrocracking, catalytic cracking, hydrotreatment of heavy oil residues; and hydrogen synthesis technologies) are discussed.  相似文献   

19.
This paper reported preparation of novel order mesoporous Mg–Al–Co hydrotalcite based catalysts through sol–gel procedure using precursors such Mg(NO3)2, Al(NO3)3 and Co(NO3)2 and Na2CO3. The catalyst also contained both acidity and basicity being very convenient for decarboxylation process of vegetable oil to green hydrocarbons. The alkaline media was maintained at pH 10 during the processes. Molar ratio of metal cations and temperature of the sol–gel processes were investigated for their effect in the mesoporous structure formation. The results showed that the procedure should be established at 70 °C with the molar Mg/Al/Co ratio of 1/5/0.2. Acidity and basicity of the mesoporous hydrotalcite based catalyst were demonstrated for their co-existence. The as-synthesized material at the suitable conditions was used as catalyst for decarboxylation of jatropha oil to obtain green hydrocarbons mainly belonging to diesel fraction. The decarboxylation was carried out at 400 °C for 3 h in closed auto-pressurized reactor exhibiting a yield of diesel involving hydrocarbons of over 70% after distillation and analysis. The result also confirmed that the acidity and basicity greatly accelerated the activity of the catalyst. Some techniques were used to characterizing the catalyst including XRD, SEM, TEM, TGA, NH3-TPD, CO2-TPD and BET, and GC–MS was also used to analyze the main product composition.  相似文献   

20.
In this study, a mathematical model is developed to predict the efficiency of a down-hole oil–water separation hydrocyclone. In the proposed model, the separation efficiency is determined based on droplet trajectory of a single oil droplet through the continuous-phase. The droplet trajectory model is developed using a Lagrangian approach in which single droplets are traced in the continuous-phase. The droplet trajectory model uses the swirling flow of the continuous-phase to trace the oil droplets. By applying the droplet trajectory, a trial and error approach is used to determine the size of the oil droplet that reaches the reverse flow region, where they can be separated. The required input for the proposed model is hydrocyclone geometry, fluid properties, inlet droplet size distribution and operational conditions at the down hole. The model is capable of predicting the hydrocyclone hydrodynamic flow field, namely, the axial, tangential and radial velocity distributions of the continuous-phase. The model was then applied for some case studies from the field tested DOWS systems which exist in the literature. The results show that the proposed model can predict well the split ratio and separation efficiency of the hydrocyclone. Moreover, the results of the proposed model can be used as a preliminary evaluation for installing a down-hole oil–water separation hydrocyclone system in a producing well.  相似文献   

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