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761.
Mehran Sohrabi Nor Idah KechutMasoud Riazi Mahmoud JamiolahmadyShaun Ireland Graeme Robertson 《Chemical Engineering Research and Design》2011,89(9):1865-1872
The 2007 IEA's World Energy Outlook report predicts that the world's energy needs will grow by 55% between 2005 and 2030, with fossil fuels accounting for 84% of this massive projected increase in energy demand. An undesired side effect of burning fossil fuels is carbon dioxide (CO2) emission which is now widely believed to be responsible for the problem of global warming. Various strategies are being considered for addressing the increase in demand for energy and at the same time developing technologies to make energy greener by reducing CO2 emissions.One of these strategies is to ‘capture’ produced CO2 instead of releasing it into the atmosphere. Capturing CO2 and its injection in oil reservoirs can lead to improved oil recovery as well as CO2 retention and storage in these reservoirs. The technology is referred to as CCS (carbon capture and storage). Large point sources of CO2 (e.g., coal-fired power plants) are particularly good candidates for capturing large volumes of CO2. However, CO2 capture from power plants is currently very expensive. In addition to high costs of CO2 capture, the very low pressure of the flue gas (1 atm) and its low CO2 content (typically 10-15%) contribute to the high cost of CO2 capture from power plants and the subsequent compression. This makes conventional CO2 flooding (which requires very large volumes of CO2) uneconomical in many oil reservoirs around the world which would otherwise be suitable candidates for CO2 injection. Alternative strategies are therefore needed to utilize smaller sources of CO2 that are usually available around oil and gas fields and can be captured at lower costs (due to their higher pressure and higher CO2 concentration).We investigate the potential of carbonated (CO2-enriched) water injection (CWI) as an injection strategy for improving recovery from oil reservoirs with the added benefit of safe storage of CO2. The performance of CWI was investigated by conducting high-pressure flow visualization as well as coreflood experiments at reservoir conditions. The results show that CWI significantly improves oil recovery from water flooded porous media. A relatively large fraction of the injected CO2 was retained (stored) in the porous medium in the form of dissolved CO2 in water and oil. The results clearly demonstrate the huge potential of CWI as a productive way of utilizing CO2 for improving oil recovery and safe storage of potentially large cumulative quantities of CO2. 相似文献
762.
Thermodynamic analysis of single‐step synthesis of dimethyl ether (DME) from syngas over a bi‐functional catalyst (BFC) in a slurry bed reactor has been investigated as a function of temperature (200–240°C), pressure (20–50 bar), and composition feed ratio (H2/CO: 1–2). The BFC was prepared by physical mixing of CuO/ZnO/Al2O3 as a methanol synthesis catalyst and H‐ZSM‐5 as a methanol dehydration catalyst. The three reactions including methanol synthesis from CO and H2, methanol dehydration to DME and water–gas shift reaction were chosen as the independent reactions. The equilibrium thermodynamic analysis includes a theoretical model predicting the behaviour and a comparison to experimental results. Theoretical model calculations of thermodynamic equilibrium constants of the reactions and equilibrium composition of all components at different reaction temperature, pressure, and H2/CO ratio in feed are in good accordance with experimental values. 相似文献
763.
In this study,strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated.Among these resins,Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions.The effect of pH,contact time,mass of resin,temperature,and concentration of interfering ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process.The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models.The results indicated that the pseudo-second order kinetic model was more appropriate than the other one.Moreover,the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data. 相似文献
764.
Nanocrystalline magnesium oxide with a high surface area and a highly defective surface structure with plate-like shape was synthesized by a facile method using polyvinyl alcohol as a surfactant. The prepared MgO was employed as support for nickel catalysts with various nickel loadings in methane reforming with carbon dioxide. The results showed high catalytic activity and stability for the prepared catalysts due to the formation of NiO–MgO solid solution and high basicity of support. The 5% Ni/MgO catalyst was very effective in this process and exhibited stable catalytic performance for 50 h of reaction as well as a high resistance against carbon formation. 相似文献
765.
Güneş Süheyla Kürkçüoğlu Tuncer Hökelek Mehran Aksel Okan Zafer Yeşilel Hakan Dal 《Journal of Inorganic and Organometallic Polymers and Materials》2011,21(3):602-610
Three new complexes [M(deten)2Ni(μ-CN)2(CN)2]
n
(M = Ni, Cu and Cd, deten = N,N-diethylethylenediamine) have been synthesized and characterized by chemical, thermal analysis, FT-IR and Raman spectroscopies.
The crystal structure of the Cd complex has been determined by X-ray single crystal diffraction. Structural study reveals
that the Ni2+ and Cd2+ ions are located on inversion centers, and adopt slightly distorted square-planar and octahedral geometries, respectively.
In the crystal structure, the intermolecular N–H⋯N hydrogen bonds link the polymeric chains into a two dimensional network.
Vibrational spectral data indicate the presence of two ν(C≡N) for complexes can be assigned to the terminal and bridging cyanides.
The decomposition reaction take places in the temperature range 30–1000 °C in the static air atmosphere. 相似文献
766.
Tashkhourian J Moradi Abdoluosofi L Pakniat M Montazerozohori M 《Journal of hazardous materials》2011,187(1-3):75-81
A simple and selective method was used for the preconcentration and determination of uranium(VI) by solid-phase extraction (SPE). In this method, a column of alumina modified with sodium dodecyl sulfate (SDS) and a new Schiff's base ligand was prepared for the preconcentration of trace uranyl(VI) from water samples. The uranium(VI) was completely eluted with HCl 2M and determined by a spectrophotometeric method with Arsenazo(III). The preconcentration steps were studied with regard to experimental parameters such as amount of extractant, type, volume and concentration of eluent, pH, flow rate of sample source and tolerance limit of diverse ions on the recovery of uranyl ion. A preconcentration factor more than 200 was achieved and the average recovery of uranyl(VI) was 99.5%. The relative standard deviation was 1.1% for 10 replicate determinations of uranyl(VI) ion in a solution with a concentration of 5 μg mL(-1). This method was successfully used for the determination of spiked uranium in natural water samples. 相似文献
767.
Ueno D Darling C Alaee M Campbell L Pacepavicius G Teixeira C Muir D 《Environmental science & technology》2007,41(6):1841-1848
Hydroxylated PCBs (OH-PCBs) are well-known metabolites of PCBs in organisms, but there has been no direct study of their presence in the abiotic environment. In this study, OH-PCBs were determined in samples of rain, snow, and surface waters from sites in Ontario, Canada. OH-PCBs were quantified by gas chromatography with high-resolution mass spectrometry (GC-HRMS)in order to provide complete characterization of all OH-PCB homolog groups. OH-PCBs and PCBs were detected in all the samples analyzed, although half of the sigmaOH-PCBs could not be identified even with 71 individual congener standards. Total concentrations of OH-PCBs (sigmaOH-PCBs) in water ranged from 0.87 to 130 pg/L and from 230 to 990 pg/g in particulate organic matter. Total fluxes of those compounds in snow and rain were from < 1 to 100 pg/m2 and from < 1 to 44 pg/ m2/day, respectively. Higher sigmaOH-PCB fluxes in rain were found in southern Ontario than in a remote north-central Ontario site possibly reflecting greater sources of precursor PCBs near urban areas. Relatively higher sigmaOH-PCB concentrations were found in surface waters from sites near sewage treatment plant (STP) outfalls in the cities of Toronto (130 pg/L) and Hamilton (35 pg/L) than in offshore samples from Lake Ontario (1.6 pg/L). The results indicate that STPs are one of the sources of OH-PCBs for lake waters in this region. Similar homolog and congener profiles in rain and offshore surface water samples suggest that atmospheric deposition is the predominant source at offshore sites. This is the first report to detect the OH-PCBs in the abiotic environment. 相似文献
768.
Robust adaptive vibration control of a flexible structure 总被引:1,自引:0,他引:1
Different types of L1 adaptive control systems show that using robust theories with adaptive control approaches has produced high performance controllers. In this study, a model reference adaptive control scheme considering robust theories is used to propose a practical control system for vibration suppression of a flexible launch vehicle (FLV). In this method, control input of the system is shaped from the dynamic model of the vehicle and components of the control input are adaptively constructed by estimating the undesirable vibration frequencies. Robust stability of the adaptive vibration control system is guaranteed by using the L1 small gain theorem. Simulation results of the robust adaptive vibration control strategy confirm that the effects of vibration on the vehicle performance considerably decrease without the loss of the phase margin of the system. 相似文献
769.
Liquid–liquid extraction process with the recommended low interfacial tension chemical system of butanol–succinic acid–water was performed in a two impinging-jets contacting device (TIJCD), working continuously with opposed impinging jets. A range of extraction efficiency of 58–96% was achieved under different conditions. Overall volumetric mass transfer coefficient and specific power input criteria clearly indicate the great performance capability of TIJCD. An increase in nozzle diameter and/or jets force results an efficiency enhancement, while increase in inter-nozzle distance leads the efficiency diminish. The overall volumetric mass transfer coefficient was satisfactorily correlated in the form of ordinary and dimensionless correlations. 相似文献
770.
In this paper, new topologies for quasi-Cuk converter are proposed. The proposed converters with different voltage and current transfer ratio and reduced voltage stress on capacitor can be employed in distributed generation (DG) systems. In this paper, steady-state analysis of two proposed quasi-Cuk converters in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is presented. Then, besides values designing of used elements, maximum and minimum values of their current and voltage are calculated. Moreover, critical inductances between CCM and DCM for the proposed converters are calculated. Unique features of the proposed converters are different transfer ratio without employing additional elements compared to the conventional Cuk converter. Comparison of the proposed converters with conventional converter in terms of voltage transfer ratio, voltage stress on capacitor, and voltage stress on switch demonstrates advantages of the proposed converters. Finally, experimental results to verify the accuracy of the proposed converters in different operating modes are presented. 相似文献