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Forecasting China's natural gas consumption based on a combination model
Ensuring a sufficient energy supply is essential to a country.Natural gas constitutes a vital part in energy supply and therefore forecasting natural gas consumption reliably and accurately is an essential part of a country's energy policy.Over the years,studies have shown that a combinative model gives better projected results compared to a single model.In this study,we used Polynomial Curve and Moving Average Combination Projection (PCMACP) model to estimate the future natural gas consumption in China from 2009 to 2015.The new proposed PCMACP model shows more reliable and accurate results:its Mean Absolute Percentage Error (MAPE) is less than those of any previous models within the investigated range.According to the PCMACP model,the average annual growth rate will increase for the next 7 years and the amount of natural gas consumption will reach 171600 million cubic meters in 2015 in China....
2020-09-15 12:28:59浏览：57
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Transformation of methane to synthesis gas over metal oxides without using catalyst
This article reviews a new developing method in the field of metal oxide reduction in chemical and metallurgical processes, which uses methane as a reducing agent. Commonly, coal is used as the reducing agent in the reduction of metal oxide and other inorganic materials; Metal producing factories are among the most intensive and concentrated source of greenhouse gases and other pollutants such as heavy metals, sulfur dioxide and fly ash. Thermodynamically, methane has a great reducing capability and can be activated to produce synthesis gas over a metal oxide as an oxygen donor. Metal oxide reduction and methane activation, two concurrent thermochemical processes, can be combined as an efficient and energy-saving process; nowadays this kind of technologies is of great importance. This new reduction process could improve energy efficiencies and significantly decrease greenhouse gas emission compared to the conventional process; furthermore, the produced gases are synthesis gas that is more valuable than methane. In this paper, thermodynamic studies and advantages of this promising method were discussed. The major aim of this article is to introduce methane as a best and environmentally friendly reducing agent at low temperature....
2020-09-15 12:28:59浏览：61
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欢盟F—gas法规隆订新进展
含氟气体（Fluorinated gases，F-gas）由于具有高能效、安全性能好及成本低等特点，广泛应用于加热和制冷领域。但随着欧盟F-gas842／2006号法规修订工作的全面展开，HFCs将面临怎样的未来？欧盟F-gas842／2006号法规主要关注F—gas的遏制以及提高人们控制这种气体的能力。虽然一些F-gas具有相对较高的全球变暖潜值（GWP），...
2020-09-15 12:28:59浏览：39
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Fast ethylamine gas sensing based on intermolecular charge-transfer complexation
We have investigated the fast ethylamine gas sensing of 2-chloro-3,5-dinitrobenzotrifluoride (CDBF) loaded poly(acrylonitrile)nanofiber based on an intermolecular charge-transfer complexation.Reversible response and recovery were achieved using alternating gas exposure.This system shows a fast ethylamine gas sensing within 0.4 s....
2020-09-15 12:28:59浏览：34
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Numerical simulation of particle tracks in the cold gas dynamic spraying process
In this study,the distribution behavior of the particle flow field in cold gas dynamic spraying(CGDS)was simulated through the computational fluid dynamics(CFD)method.Traces of the particles with different diameters in the gas flow field were analyzed,and effects of flat and sphere substrates on the particle tracks were also compared.Simulation results indicate that different escaping directions of particles flow with the two substrates.These investigations gave instructions on how to design the powder recovery and dusting machines in a CGDS system....
2020-09-15 12:28:59浏览：66
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Progress in the application of cold gas dynamic spraying to repairing continuous casting molds
A new continuous casting mold repairing method-cold gas dynamic spraying(CGDS)is introduced.The study investigates the advantages of the CGDS process regarding repairing operation,such as convenient,in-situ repairation,little heat delivery,microstructural and dimensional stability and other special applications.Microstructure and mechanical properties of the copper alloy coating,nickel coating,ceramic composite coating,and their interface to the substrates,which are usually used in repairing operation have been researched by means of optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and micro-hardness tests.Experimental results have demonstrated the relative density of the copper alloy coating is as high as 98.7%,and that no obvious diflference Can be observed between the CrZrCu substrate and the Cu alloy coating in terms of microstmctures;thus the interface is quite difficult to be identified.The bonding strength and micro-hardness of the Cu alloy coating reach up to 37 MPa and 310 HV0. 2,respectively.The interface between the copper alloy coating and the nickel coating is either zigzag or wave shaped,and the cohesion is relatively good.As-sprayed nickel coating is dominated by severely deformed particles,and the relative density is up to 98.5%.Complete recrystallization occurred after annealing at 900℃ for one hour,while its micro-hardness remains as high as 124.1HV0.2. All these results have indicated that CGDS is a promising technology for repairing the continuous casting mold and that its future development is prosperous as well....
2020-09-15 12:28:59浏览：69
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Simultaneous removal of ethyl acetate, benzene and toluene with gliding arc gas discharge
The simultaneous removal of ethyl acetate, benzene and toluene with relatively low or high initial concentration is studied using a laboratory scale gliding arc gas discharge (GA) reactor. Good decomposition efficiencies are obtained which proves that the GA is effective for the treatment of volatile organic compounds (VOCs) with either low or high concentration. A theoretical decomposition mechanism is proposed based on detection of the species in the plasma region and analysis of the decomposition by-products. This preliminary investigation reveals that the GA has potential to be applied to the treatment of exhaust air during color printing and coating works, by either direct removal or combination with activated carbon adsorption/desorption process....
2020-09-15 12:28:59浏览：52
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Physical Simulation of Water Dissolved Gas (WDG)During Migration
By using the equipment designed and developed by ourselves, experiment of investigating the influence of dissolution on some geo-chemical parameters (such as Δ13c,Δd,and Ic4/Nc4 in water-dissolved gas (WDG) during migration) was performed. The result shows that, with the increase of distance, 1) the relative abundance of non-hydrocarbon (CO2) and hydrocarbon (CH4) increase while the relative abundance of hydrocarbon (C2+) decreases (the relative abundance of hydrocarbon (C5+) can be basically negligible); 2) the relative abundance of benzene and methylbenzene increase in the initial time and then decrease. The carbon and hydrogen isotopes of methane vary slightly, which can be regarded as indicators of gas dissolved in water formation....
2020-09-15 12:28:59浏览：65
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Study of properties and mechanisms of backing weld of stainless steel piping with no backing gas
This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases (He+Ar+CO_2). The protection mechanism was also discussed from the view of arc physics and the alloy elements in the solid wire. The result shows that when the proportion of helium in the above-noted mixed gases excesses 45 percent, the mechanical properties and the intergranular corrosion tendency meet corresponding Chinese standards. Further, the alloy elements in the solid wire can react with oxygen during the period of high temperature boosted by helium arc; this result in the formation of a bed of thin slag, which can avoid the oxidation of the backing weld and eliminate the need of backing gas....
2020-09-15 12:28:59浏览：91
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Gas seepage on the sea floor of Okinawa Trough Miyako Section
A marine geophysical survey was carried out, on the R/V Science 1 of the Institute of Oceanography, Chinese Academy of Sciences (IOCAS), in 2000, at the Miyako Section of Okinawa Trough. Here we present seismic and acoustic evidence of a gas seep on the sea floor on the western part of the Okinawa Trough, near the lower slope of the East China Sea Slope and discuss the possibility of related formation of gas hydrate. A gas column reflection was observed in echo-sounder data above a section where the sea floor reflector was missing, on both the echo-sounder and the seismic data for line H14. The seismic data also show an acoustic curtain reflection and a turbidity reflection at this section. These anomalies are the evidence of the existence of a gas seep, which occupies an area 2.2 km in diameter. Based on the acoustic curtain on line H14, we believe that the amount of gas contained in the sediments below the gas seep is larger than 1% by volume of sediment. Tectonically, the gas seep developed in a small basin controlled by basement uplift in the north, south and east. The thickness of the sediment layer can be greater than 3.5 km. A mud diapir structure was found in layer D beneath the gas seep. Over-pressure may occur due to the large sediment thickness and also the tectonic basement uplift in the north, south, and east. The mud diapir could be the preferential pathway for methane-rich fluids. The acoustic curtain may indicate that free gas related to the gas seep can be formed on the sea floor. We also note that the layer above the acoustic curtain on profile H14 may contain gas hydrate....
2020-09-15 12:28:59浏览：57
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Numerical simulation for explosion wave propagation of combustible mixture gas
A two-dimensional multi-material code was indigenously developed to investigate the effects of duct boundary conditions and ignition positions on the propagation law of explosion wave for hydrogen and methane-based combustible mixture gas. In the code, Young's technique was employed to track the interface between the explosion products and air, and combustible function model was adopted to simulate ignition process. The code was employed to study explosion flow field inside and outside the duct and to obtain peak pressures in different boundary conditions and ignition positions. Numerical results suggest that during the propagation in a duct, for point initiation, the curvature of spherical wave front gradually decreases and evolves into plane wave. Due to the multiple reflections on the duct wall, multi-peak values appear on pressure-time curve, and peak pressure strongly relies on the duct boundary conditions and ignition position. When explosive wave reaches the exit of the duct, explosion products expand outward and forms shock wave in air. Multiple rarefaction waves also occur and propagate upstream along the duct to decrease the pressure in the duct. The results are in agreement with one-dimensional isentropic gas flow theory of the explosion products, and indicate that the ignition model and multi-material interface treatment method are feasible....
2020-09-15 12:28:59浏览：48
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Propagation of an Electromagnetic Wave in a Mixing of Plasma-dense Neutral Gas
The propagation of a normal incident electromagnetic plane wave in a mixture of rare plasma and dense neutral gas is investigated by one dimensional model. The numerical results show that the amplitude of wave electric field is decayed dramatically and its phase is modulated obviously in a distance of a few wave lengthes due to the frequent collisions between electrons and neutrals ( the collision frequency vc is near or even larger than the wave frequency ω0)....
2020-09-15 12:28:59浏览：31
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Tectonic evolution of the Changling fault basin and its relationship to oil and gas accumulation
The Changling fault depression passed through three stages of evolution:a period of faulting,a period of subsidence,and an inversion period.The fault lifted the whole area and the formation was eroded during the late Yingcheng formation,the late Nenjiang formation,and the late Mingshui formation.The denudation quantity of eight wells located in the study area is estimated by the interval transit time method and by the formation trend extension method using seismic and drilling data.Inversion back stripping technology with de-compaction correction was used to restore the original sedimentary thickness step by step and to recover the burial history at a single well.Two profiles were selected for the recovery and study of the tectonic evolution.The study confirmed that the primary major gas bearing structure formed due to thermal shrinkage lifting during the late Yingcheng formation.Successive development in a pattern during the late Mingshui formation led to the formation of the primary gas pool.Vertical differential uplift during the late Nenjiang formation formed the Fulongquan structure during the late Paleogene.At this same time a secondary gas pool formed.A large scale reverse developed late in the Mingshui formation that provided the impetus for formation of a secondary gas pool.It is thought that the migration and accumulation of oil and gas was controlled by lithologic character,fracture,and structure.The local uplift in the vicinity of the hydrocarbon recession is most conducive to the collection of hydrocarbon gas....
2020-09-15 12:28:59浏览：69
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Breakdown Voltage Research of Penning Gas Mixture in Plasma Display Panel
Paschen law and equations, which ignore the influence of the Penning ionization on the electron ionization coefficient (α), are always used as the approximation of the breakdown voltage criterion of the Penning gas mixture in current researches of discharge characteristics of the plasma display panel (PDP). It is doubtful that whether their results match the facts. Based on the Townsend gas self-sustaining discharge condition and the chemical kinetics analysis of the Penning gas mixture discharging in PDP, the empirical equation to describe the breakdown of the Penning gas mixture is given. It is used to calculate the breakdown voltage curves of Ne-Xe/MgO and Ne-Ar/MgO in a testing macroscopic discharge cell of AC-PDP. The effective secondary electron emission coefficients (γeff) of the MgO protective layers are derived by comparing the breakdown voltage curves obtained from the empirical equation with the experimental data of breakdown voltages. In comparison with the results calculated by the Paschen law and the equation which ignore the influence of the Penning ionization on α , the results calculated by the empirical equation have better conformity with experimental data. The empirical equation characterizes the breakdown of the Penning gas mixture in PDP effectively, and gives a convenient way to study its breakdown characteristics and the secondary electron emission behaviors....
2020-09-15 12:28:59浏览：60
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Surface characterization of ashtree wood meal by inverse gas chromatography
Inverse gas chromatography (IGC) is a sensitive and convenient method to characterize surface properties and thermodynamic parameters of solid materials. Surface properties of ashtree wood meal were determined by inverse gas chromatography in this work. The dispersive component of the surface free energy and acid-base parameters of the ashtree wood meal were characterized. The dispersive component of surface free energy was within 36-39 mJ/m2, the Lewis acidic number Ka was 0.53, and the basic number Kb was 0.21, respectively. The results show that ashtree is amphoteric and predominantly acidic wood....
2020-09-15 12:28:59浏览：42
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