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Progress in studies of natural gas conversion in China
Progress in natural gas conversion in China is presented in this paper, including processes of natural gas to synthesis gas (syngas), syngas to liquid hydrocarbons, oxygenates synthesis, methanol to olefins (MTO), methane to aromatics and oxidative coupling of methane (OCM)....
2020-09-13 23:35:02浏览：75
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"Redistribution" Effect of Lumpy Zone for Gas Flow in BF
The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping,cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high-temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called "redistribution" effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone....
2020-09-13 23:35:02浏览：101
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INFLUENCE OF CHEMICAL ADDITIVES ON GAS HYDRATE FORMATION
One surfactant as sodium dodecyl sulfate (SDS) and one synthesized sample as gas hydrate inhibitor are introduced in this paper. Through experiments we prove sodium dodecyl sulfate can accelerate the formation rate of gas hydrate and the synthesized sample can inhibit the formation and growth....
2020-09-13 23:35:02浏览：50
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Comparison of three methods for natural gas dehydration
This paper compares three methods for natural gas dehydration that are widely applied in industry:(1) absorption by triethylene glycol,(2)adsorption on solid desiccants and (3) condensation.A comparison is made according to their energy demand and suitability for use.The energy calculations are performed on a model where 105 Nm3/h water saturated natural gas is processed at 30 ℃.The pressure of the gas varies from 7 to 20 MPa.The required outlet concentration of water in natural gas is equivalent to the dew point temperature of - 10 ℃ at gas pressure of 4 MPa....
2020-09-13 23:35:02浏览：55
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Rapidly Estimating Natural Gas Compressibility Factor
Natural gases containing sour components exhibit different gas compressibility factor (Z) behavior than do sweet gases. Therefore, a new accurate method should be developed to account for these differences. Several methods are available today for calculating the Z-factor from an equation of state. However, these equations are more complex than the foregoing correlations, involving a large number of parameters, which require more complicated and longer computations. The aim of this study is to develop a simplified calculation method for a rapid estimating Z-factor for sour natural gases containing as much as 90% total acid gas. In this article, two new correlations are first presented for calculating the pseudo-critical pressure and temperature of the gas mixture as a function of the gas specific gravity. Then, a simple correlation on the basis of the standard gas compressibility factor chart is introduced for a quick estimation of sweet gases' compressibility factor as a function of reduced pressure and temperature. Finally, a new corrective term related to the mole fractions of carbon dioxide and hydrogen sulfide is developed....
2020-09-13 23:35:02浏览：45
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Research on flaky and vertical gas diffusion electrode
Flaky and vertical gas diffusion electrode was propos, ed to improve the efficiency of fuel cells. The discharge experiments were done to compare the discharge capability of the electrode with different PTFE ingredient and different basal body uniformity. The results showed the electrode with 10% PTFE and high uniformity was favorable to discharge. This single electrode could discharge about 100 h at 150 mA(no noble metal catalyst). The electrode made of the punched screens was superior to that made of the foam Ni....
2020-09-13 23:35:02浏览：65
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Similarity of ideal gas flow at different scales
The similarity of ideal gas flow at different scales is investigated analytically and numerically. With the compressible and rarefied effects considered, two dimensionless parameters, Mach number and Knudsen number, are proposed as the similarity criterions, because the Reynolds number can be expressed by the Mach number and the Knudsen number of ideal gases. A DSMC method is used to simulate flows at different scales with the same Ma and Kn, including subsonic channel flows and the supersonic flows over a hot plate. Comparisons between the results of different scales show that the normalized fields of macroscopic quantities are the same. This confirms the similarity. Especially, the results indicate that the micro flow are similar to the rarefied flow of ideal gas, which suggests that many transformations are available from the existing rarefied flow results to the micro flow....
2020-09-13 23:35:02浏览：61
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Surface Characterization of Glass Fiber by Inverse Gas Chromatography
The surface properties of glass fiber were quantificationally analyzed by inverse gas chromatography (IGC). Five n-alkanes (C6, C7, C8, C9, and C10) were chosen as apolar probes to characterize the dispersive component of surface free energy. Trichloromethane (CHCl3), acetone,and tetrahydrofuran (THF) were chosen as polar probes to detect the Lewis acid-base parameters. It is found that the dispersive components of free energy are 32.3, 30.5, 27.5, and 26.9 Mj/m2 at 70,80, 90, and 100 ℃, respectively. The Lewis acidic number Ka of the glass fiber is 0.512 4, and the basic number Kb is 2.862. The results mean the glass fiber is a Lewis basic material....
2020-09-13 23:35:02浏览：71
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Potential recoverable natural gas resources in China
Natural gas resources in China are abundant. The undiscovered recoverable natural gas resources in China are estimated to be 19.27×1012 m3. Natural gas is mainly distributed in the middle and west China and offshore areas of China. The Tarim Basin, Sichuan Basin, Ordos Basin, East China Sea Basin, Tsaidam Basin, Yinggehai Basin, and Qiongdongnan Basin are the main gas-beating basins. The natural gas resources are not distributed evenly and are under-explored in China. The deeper horizons in east China, foreland basins and craton paleo-uplifts in the middle and west China, and the offshore basins are the main exploration areas in the future....
2020-09-13 23:35:02浏览：66
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Recent progress of nuclear liquid gas phase transition
Recent progress on nuclear liquid gas phase transition (LGPT) has been reviewed, especially for the signals of LGPT in heavy ion collisions. These signals include the power-law charge distribution, cluster emission rate, nuclear Zipf law, bimodality, the largest fluctuation of the fragments, △ -scaling, caloric curve, phase coexistence diagram, critical temperature, critical exponent analysis, negative specific heat capacity and spinodal instability etc. The systematic works of the authors on experimental and theoretical LGPT are also introduced....
2020-09-13 23:35:02浏览：52
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Shale Gas Play Screening and Evaluation Criteria
The uniqueness of shale gas plays is contrasted with conventional oil and gas exploration. Based on our ten year history in shale gas exploration, a practical 17 point list of criteria to use for screening shale gas projects and ranking that encompasses geoscience, geochemistry, reservoir engineering, drilling, completions and production operations is developed and explained. Other considerations that will impact shale gas development are identified and discussed. Some key methodologies to incorporate in the evaluation process are also proposed. The outcome of this proposed screening process, if rigorously applied,should quickly identify the projects that have the most likely chance for success for recommendation to management. Examples from active shale gas plays in the United States are used to support these criteria and references to relevant recent publications and presentations are provided....
2020-09-13 23:35:02浏览：70
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Siylated and acetylated β-cyclodextrins for gas chromatographic stationary phases
Two new chiral stationary phases, 2,3-di-O-acetyl-6-O-trimethylsilyl-β-cyclodextrin (DATBCD)and 2, 6-di-O-trimethylsilyl-3-O-acetyl-β-cyclodextrin (DTABCD), were synthesized, their structures were identified by memos of infrared and NMB spectra. Capillary columns were coated with the two stationary- phases by dynamic method. The chromatographic properties, and enantiomers separation, such as ketone, esters, alcohols and olefines, were investigated on the silylated and acetylated β-cyclodextrin stationary phases. The expehmental results show that the silylated and acetylated β-cyclodextrins are suitable to be used as capillary gas chromatographic stationary phases, the relative polarity of DATBCD and DTABCD stationary phases is respectively 4143 and 3928, the colmnn efficiencies are respectively 3084 and 4198, and DATBCD is of stronger enantioselectivity- than DTABCD, capacity factor of the first eluted enantiomer ( k1 ) and separation factor(α)of α-phenylethanol on DATBCD stationary phase are respectively 8.23 and 1.019....
2020-09-13 23:35:02浏览：76
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Effects of salinity on methane gas hydrate system
Using an approximately analytical formation,we extend the steady state model of the pure methane hydrate system to include the salinity based on the dynamic model of the methane hydrate system.The top and bottom boundaries of the methane hydrate stability zone (MHSZ) and the actual methane hydrate zone (MHZ),and the top of free gas occurrence are determined by using numerical methods and the new steady state model developed in this paper.Numerical results show that the MHZ thickness becomes thinner with increasing the salinity,and the stability is lowered and the base of the MHSZ is shifted toward the seafloor in the presence of salts.As a result,the thickness of actual hydrate occurrence becomes thinner compared with that of the pure water case.On the other hand,since lower solubility reduces the amount of gas needed to form methane hydrate,the existence of salts in seawater can actually promote methane gas hydrate formation in the hydrate stability zone.Numerical modeling also demonstrates that for the salt-water case the presence of methane within the field of methane hydrate stability is not sufficient to ensure the occurrence of gas hydrate,which can only form when the methane concentration dissolved in solution with salts exceeds the local methane solubility in salt water and if the methane flux exceeds a critical value corresponding to the rate of diffusive methane transport.In order to maintain gas hydrate or to form methane gas hydrate in marine sediments,a persistent supplied methane probably from biogenic or thermogenic processes,is required to overcome losses due to diffusion and advection....
2020-09-13 23:35:02浏览：25
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Simulation Analysis of Indoor Gas Explosion Damage
The influence factors and process of indoor gas explosion are studied with AutoReaGas explosion simulator. The result shows that venting pressure has great influence on the indoor gas explosion damage. The higher the venting pressure is, the more serious the hazard consequence will be. The ignition location has also evident effect on the gas explosion damage. The explosion static overpressure would not cause major injury to person and serious damage to structure in the case of low venting pressure (lower than 2 kPa). The high temperature combustion after the explosion is the major factor to person injury in indoor gas explosion accidents....
2020-09-13 23:35:02浏览：72
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Desulfurizing absorbent for flue gas and its absorption mechanism
A new desulfurizing absorbent for flue gas, i.e., anorganic physical solvent of DMSO(dimethyl sulfoxide) mixed with arelatively small amount of chemical solvent(Mn2+) was studied.Compared with pure physical solvent of DMSO, the purificationefficiency of the new absorbent has been much improved. And itsabsorption and reaction mechanism are discussed....
2020-09-13 23:35:02浏览：53
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