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HYGAS 气化技术及应用分析
介绍了HYGAS气化技术的工艺流程、技术特点和性能指标等，并对其工业应用领域进行分析。分析表明，其煤种适应性宽，碳转化效率高，物耗能耗低，较适用于以煤制合成气和IGCC的方式，可对包括褐煤在内的低阶煤进行处理利用。...
2020-06-12 16:20:36浏览：1447
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Effect of Mild-calcined Coal Gangue Addition on Hot Strength and Refractoriness Under Load of Ultra
This work explored the way to improve hot modulus of rupture (HMOR) and refractoriness under load ( RUL ) by adding mild-calcined coal gangue ( MCG )in Al203 - SiO2 ultra low cement (ULC) castables,making use of the in-situ effect of the MCG during heating-up.The influence of respective additions of 5％,10％ and 15％ of the MCG powders calcined at 700 ℃was investigated on HMOR at 1 400 ℃ and RUL of the castables.With increased addition of the MCG,HMOR and RUL become significantly enhanced.At 10％ of the MCG addition,HMOR reaches 3 MPa,as compared to 0.3 MPa in the case of no MCG addition.RUL of the specimens dried at 110 ℃ for 24 h can be increased by some 270 ℃ with 10％ of the MCG addition.RUL of the specimens preheated at 1 500 ℃ for 3 h maintaius the growth trend with the MCG addition increasing.The microstructure of the heated castable samples was investigated by means of SEM.The in-situ formed needle-like and interlaced mullite in the matrix is contributive to the improvement....
2020-06-12 16:19:59浏览：1420
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Isolated 4-20 mA Current-Loop System in the Experiment of Coal Pyrolysis in H-plasma Producing Acety
The purpose of this paper is to demonstrate a systematic approach to design high performance signal conditioning circuits, and to show how to implement the 4-20 mA analog current-loop transmitter and receiver circuits by using isolation amplifier.The basic principle and typical applicable circuits of the 4-20 mA current loop isolation chip Tll00N, the current-limiting circuit and filter circuit are presented.And the experimental testing data of the circuits are analyzed....
2020-06-12 16:19:52浏览：1423
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Modeling seismic wave propagation in a coal-bearing porous medium by a staggered-grid finite differe
A staggered-grid finite difference method is used to model seismic wave records in a coal bearing,porous medium.The variables analyzed include the order of the difference calculations,the use of a perfect match layer to provide absorbing boundary conditions,the source location,the stability conditions,and dispersion in the medium.The results show that the location of the first derivative of the dynamic variable with respect to space is coincident with the location of the first derivative of the kinematic variable with respect to time.Outgoing waves are effectively absorbed and reflection at the boundary is very weak when more than 20 perfect match layer cells are used.Biot theory considers the liquid phase to be homogeneous so the ratio of liquid to solid exposure of the seismic source depends upon the medium porosity.Numerical dispersion and generation of false frequencies is reduced by increasing the accuracy of the difference calculations and by reducing the grid size and time step.Temporal second order accuracy,a tenth order spatial accuracy,and a wavelength over more than ten grid points gave acceptable numerical results.Larger grid step sizes in the lateral direction and smaller grid sizes in the vertical direction allow control of dispersion when the medium is a low speed body.This provides a useful way to simulate seismic waves in a porous coal bearing medium....
2020-06-12 16:19:48浏览：1424
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Coal Ash Slag Penetration Behavior on Cr2O3-Al2O3-ZrO2 Bricks
The penetration behavior of different kinds of coal ash slags into chrome corundum bricks was studied by cup test. As a preliminary attempt, the oxides of Fe2O3 and MgO were added into coal ash to reduce the erosion of refractories. Different cup tests were carried out to study coal slag erosion to the refractories. FactSage was used to simulate the phase diagram of the main chemical compositions in coal ash and in the refractories. Both results agreed with each other. The results show that the elements in coal slag can penetrate into bricks and the penetration deepens with the duration increasing; it is difficult for Fe but easier for Ca and Si to penetrate into bricks; different kinds of melting coal ashes penetrate into refractories differently and the penetration depth of silicon and calcium can be significantly reduced by adding oxides into coal ash....
2020-06-12 16:19:47浏览：1404
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Prediction of oxygen concentration and temperature distribution in loose coal based on B P neural ne
An effective method for preventing spontaneous combustion of coal stockpiles on the ground is to control the air-flow in loose coal. In order to determine and predict accurately oxygen concentrations and temperatures within coal stockpiles, it is vital to obtain information of self-heating conditions and tendencies of spontaneous coal combustion. For laboratory conditions, we de-signed our own experimental equipment composed of a control-heating system, a coal column and an oxygen concentration and temperature monitoring system, for simulation of spontaneous combustion of block coal (13-25 ram) covered with fine coal (0-3 mm). A BP artificial neural network (ANN) with 150 training samples was gradually established over the course of our experiment. Heating time, relative position of measuring points, the ratio of fine coal thickness, artificial density, voidage and activation energy were selected as input variables and oxygen concentration and temperature of coal column as output variables. Then our trained network was applied to predict the trend on the untried experimental data. The results show that the oxygen concentration in the coal column could be reduced below the minimum still able to induce spontaneous combustion of coal-6% by covering the coal pile with fine coal, which would meet the requirement to prevent spontaneous combustion of coal stockpiles. Based on the predic-tion of this ANN, the average errors of oxygen concentration and temperature were respectively 0.5% and 7 ~C, which meet actual tolerances. The implementation of the method would provide a practical guide in understanding the course of self-heating and spontaneous combustion of coal stockpiles....
2020-06-12 16:19:45浏览：1438
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Two-stage numerical simulation for temperature profile in furnace of tangentially fired pulverized c
Considering the fact that the temperature distribution in furnace of a tangential fired pulverized coal boiler is difficult to be measured and monitored, two-stage numerical simulation method was put forward. First, multi-field coupling simulation in typical work conditions was carried out off-line with the software CFX-4.3, and then the expression of temperature profile varying with operating parameter was obtained. According to real-time operating parameters, the temperature at arbitrary point of the furnace can be calculated by using this expression. Thus the temperature profile can be shown on-line and monitoring for combustion state in the furnace is realized. The simul-ation model was checked by the parameters measured in an operating boiler, DG130-9.8/540. The maximum of relative error is less than 12% and the absolute error is less than 120 ℃, which shows that the proposed two-stage simulation method is reliable and able to satisfy the requirement of industrial application....
2020-06-12 16:19:43浏览：1436
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Effect of unburned carbon content in fly ash on the retention of 12 elements out of coal-combustion
The aim of this study was to evaluate whether unburned carbon particles present in fly ash can help in the retention of S,CI,Br,As,Se,Cu,Ni,Zn,Ga,Ge,Rb,and Pb out of flue gas during the coal combustion at fluidised-bed power station where the coal was combusted along with limestone.The competitive influence of 10％-25％ CaO in fly ashes on the distribution of studied elements was studied as well to be clear which factor governs behaviour of studied elements.Except of S (with significant association with CaO) and Rb and Pb (with major affinity to Al2O3) the statistically significant and positive correlation coefficients were calculated for the relations between unburned carbon content and Br (0.959),Cl (0.957),Cu (0.916),Se (0.898),Ni (0.866),As (0.861),Zn (0.742),Ge (0.717),and Ga (0.588) content.The results suggest that the unburned carbon is promising material in terms of flue gas cleaning even if contained in highly calcareous fly ashes....
2020-06-12 16:19:41浏览：1436
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Comparing potentials for gas outburst in a Chinese anthracite and an Australian bituminous coal mine
Gas outbursts in underground mining occur under conditions of high gas desorption rate and gas content, combined with high stress regime, low coal strength and high Young’s modulus. This combination of gas and stress factors occurs more often in deep mining. Hence, as the depth of mining increases, the poten-tial for outburst increases. This study proposes a conceptual model to evaluate outburst potential in terms of an outburst indicator. The model was used to evaluate the potential for gas outburst in two mines, by comparing numerical simulations of gas flow behavior under typical stress regimes in an Australian gassy mine extracting a medium-volatile bituminous coal, and a Chinese gassy coal mine in Qinshui Basin (Shanxi province) extracting anthracite coal. We coupled the stress simulation program (FLAC3D) with the gas simulation program (SIMED II) to compute the stress and gas pressure and gas content distribution following development of a roadway into the targeted coal seams. The data from gas content and stress distribution were then used to quantify the intensity of energy release in the event of an outburst....
2020-06-12 16:19:40浏览：1434
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Desulfurization kinetics of ZnO sorbent loaded on semi-coke support for hot coal gas
Zn-based sorbent (Z20SC) prepared through semi-coke support in 20 wt％ zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2S can not be nearly detected in the outlet gas before 20 h breakthrough time.The effects of the main operational conditions and the particle size of Z20SC sorbent on its desulfurization performances sorbent were investigated in a fixed-bed reactor and the desulfurization kinetics of Z20SC sorbent removing H2S from hot coal gas was calculated based on experimental data.Results showed that the conversion of Z20SC sorbent desulfurization reaction increased with the decrease of the particle size of the sorbent and the increases of gas volumetric flow rate,reaction temperature and H2S content in inlet gas.Z20SC sorbent obtained from hydrothermal synthesis by high-pressure impregnation possessed much larger surface area and pore volume than semi-coke support,and they were significantly reduced after the desulfurization reaction.The equivalent grain model was reasonably used to analyze experimental data,in which ks =4.382 × 10-3 exp(-8.270 × 103/Rg T) and Dep =1.262 × 10-4 exp(-1.522 × 104/RgT).It suggests that the desulfurization reaction of the Z20SC sorbent is mainly controlled by the chemical reaction in the initial stage and later by the diffusion through the reacted sorbent layer....
2020-06-12 16:19:38浏览：1408
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Effects of coal rank,Fe304 amounts and activation temperature on the preparation and characteristics
Coal-based Magnetic Activated Carbons(CMAC's)were prepared from three representative coal samples of various ranks:Baorigele lignite from Inner Mongolia; Datong bitumite from Shanxi province; and Taixi anthracite from Ningxia Hui Autonomous Region.Fe3O4 was used as a magnetic additive.A nitrogen-adsorption analyzer was used to determine the specific surface area and pore structure of the resulting activated carbons.The adsorption capacity was assessed by the adsorption of iodine and methylene blue.X-ray diffraction was used to measure the evolution behavior of Fe3O4 during the preparation process.Magnetic properties were characterized with a vibrating-sample magnetometer.The effect of the activation temperature on the performance of CMAC's was also studied.The results show that,compared to Baorigele lignite and Talxi anthracite,the Datong bitumite is more appropriate for the preparation of CMAC's with a high specific surface area,an advanced pore structure and suitable magnetic properties.Fe3O4 can effectively enhance the magnetic properties and control the pore structure by increasing the ratio of mesopores.An addition of 6.0% Fe3O4 and an activation temperature of 880 ℃ produced a CMAC having a specific surface area,an and 4.623 emu/g,respectively.The coal used to prepare this specimen was Datong bitumite....
2020-06-12 16:19:36浏览：1431
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Study on Filling Cross-Roadway in Fully-Mechanized Coal Faces with High Water-Content Material
A new method using high water-content material to mechanically fill cross-roadways to form artificial bottom for coal faces was introduced. The reasonable determination of filling range, the optimization of the compounding ratio of high water-content material, and the filling technique were discussed in detail. This new method has been spread after industrial testing in Baodian Colliery. Compared with the traditional method, the manual wooden chock method, the new one decreases about 40% of the filling range and cost in dealing every one set of cross-roadway in the testing condition....
2020-06-12 16:19:34浏览：1419
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Landscape pattern and its restoration for coal mine subsidence area in southern part of Tangshan in
To investigate the ecosystem damage and environment pollution resulted from coal resources exploitation, based on remote sensing image, the landscape pattern was quantitatively analyzed with GIS and landscape pattern analysis software FRAGSTATS by utilizing multiform landscape pattern indexes, such as patch area,patch circumference, patch number, fractal dimension, fragmentation index, connectivity index and so on. Resuits indicate that the restored landscape type occupies the control status and accounts for the majority of the whole area, and needs to be further restored and adjusted because of its internal body with smaller patches,lower fractal dimension and better connectivity. The landscape type without restoration has destroyed the ecology and beauty of the whole landscape. In addition, some suggestive instructions for restoring various kinds of patches are put forward according to the quantitative analysis....
2020-06-12 16:19:31浏览：1420
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Preparation,characterization and salt-resistance of a coal based super absorbent composite
Potassium humate was extracted from brown coal.A novel super absorbent composite,poly (acrylic acid-co-acrylamide)/potassium humate (PAA-AM/KHA),was prepared by graft polymerization of acrylic acid,acrylamide and coal based potassium humate using N,N'-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator.The effects of reaction temperature,degree of neutralization of the poly (acrylic acid) and the amounts of crosslinker,initiator and potassium humate were investigated.Salt resistance tests were also carried out.The composite prepared under optimal conditions had a potassium humate content of 10% and exhibited a water absorption of 770 g/g in distilled water,and 349,286 and 41 g/g in 0.5 mol/L KC1,MgCl2 and AlCl3 solutions respectively.The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly (acrylic acid-co-acrylamide) because of the collaborative effect of functional groups of the coal based potassium humate.The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy.Introduction of potassium humate into the poly (acrylic acid-co-acrylamide) structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments.The salt resisting property of the composite is improved,production costs are reduced and the growth stimulant effect is still present....
2020-06-12 16:19:31浏览：1426
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