2017年03期目次

  • Research progress and prospect of sulfur migration and transformation in coal liquefaction residue

    Chang Weike;Xu Jie;Sun Wei;Chen Shengli;Zhang Shengzhen;State Key Laboratory of Heavy Oil Processing,China University of Petroleum( Beijing);National Institute of Clean-and-Low-Carbon Energy;

    Based on the research status of sulfide migration and transformation in coal liquefaction residue,the origin and distribution of sulfur in coal liquefaction residue were introduced.The migration and transformation process of sulfide in coal liquefaction residue during hydrogenation,gasification,pyrolysis and combustion were summarized.The influencing factors of sulfur conversion were described,and the development prospect of sulfur migration and transformation in coal liquefaction residue was forecasted.The results show that sulfur in inorganic minerals is gradually convertes to organic sulfur,and H_2S is the important medium in the conversion process. The gaseous sulfides,such as H_2S,CS_2 and SO_2,are the main gaseous by-products during the conversion of coal liquefaction residue.Part of the sulfide is converted to macromolecular organic sulfur as the secondary product,affecting the quality and use of products.In order to rationally and effectively utilize the coal liquefaction residue,it is necessary to develop new approaches for converting inorganic sulfur into elemental sulfur or macromolecule organic sulfur.The recycling of gas sulfide and development of new coal liquefaction catalyst with less elemental sulfur additive are feasible.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 134K]

  • Progress on the formation mechanism of biomass soot particles

    Tian Hong;Liao Zhengzhu;College of Mechanical and Electrical Engineering,Guangdong University of Petrochemical Technology;

    The formation mechanism of soot particles in biomass combustion was introduced.It mainly included the various formation routes of biomass soot particles,the intermediate product polycyclic aromatic hydrocarbons( PAHs) of biomass soot particles,and the intermediate products polycyclic aromatic hydrocarbons to produce biomass soot particles.The influence of polycyclic aromatic hydrocarbons,reaction atmosphere,and reaction pressure and reaction temperature on the formation of soot,and the effect of metal ions on the formation of soot and soot growth process were analyzed.The shortcomings of the existing research on the formation mechanism of soot particles were summarized.The research of the intermediate products of biomass soot and the first and two formation mechanism of biomass soot,as well as the various factors of generation quantity of biomass soot should be systematically studied.formation mechanism of biomass soot was analyzed by using quantum chemical theory,moment and laser detection experiments,and it can learn from the formation mechanism of coal-fired soot and diesel soot formation mechanism and experiment research method.The formation mechanism of biomass soot should be discussed by the thermodynamics,dynamics theory,the evolution of nucleation,and the influencing mechanism. From the perspective of chemical reaction and engineering thermophysics,the evolution behavior of formation mechanism of soot particles and the growth behavior process of biomass soot nuclei can be deeply studied,and reasonable formation mechanism of biomass soot can be obtained.the.This study provides the theoretical and practical guidance for the practical engineering application of reducing the environmental impact of smog.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 350K]

  • Progress of the methanation technology in China

    Gao Zhen;Hou Jianguo;Mu Xiangyu;Wang Xiulin;Song Pengfei;Zhang Yu;Zhang Bo;CNOOC Gas and Power Group;

    Methanation technology is important for coke oven gas( COG) and coal to synthetic natural gas( SNG).Domestic research institutions were active in this field to break through the monopoly of foreign companies. This paper systematically reviewed the progress of methanation,mainly analyzed its present application status in the field of COG,and briefly introduced its application prospect in the field of SNG.To reduce the risk of its industrial application for the first time,some advices were put forward.Domestic technologies had been widely developed,and achieved commercial applications in COG with higher market share than foreign technologies.The technology had also beeh successfully developed in coal to SNG,with a bright industrial application prospect. It was advised to refer experiences from other similar engineering projects and to pay more attention to security analysis and equipment selection when first apply domestic technologies.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 98K]

  • Distribution characteristics and enrichment regularity of harmful trace elements in Shanxi coal

    Liu Hanbin;Li Miao;Guo Yanxia;Cheng Fangqin;Institute of Resources and Environmental Engineering,Shanxi University;Coal Geological Bureau of Shanxi Province;Coal Geological Exploration 148 Institute of Shanxi Province;

    In order to further clarify the distribution and enrichment characteristics of harmful trace elements in Shanxi coal and promote the clean and efficient utilization of coal,four common harmful elements such as fluorine,chlorine,arsenic and mercury in Shanxi coal were discussed.It is found that the harmful elements in Shanxi coal have the characteristics of low fluorine and high chlorine,and carboniferous Permian coal are low fluorine,low arsenic,low mercury,high chlorine,and Jurassic coal are high mercurg,high arsenic,high chlorine and low fluoride.Chlorine is mainly enriched in Xishan mining area and Huozhou mining area.Arsenic is mainly concentrated in Datong Jurassic mine and Qinshui coal field Wuxia mining area.Mercury is mainly concentrated in Pingshuo mining area and Xishan mining area.The main factors controlling the enrichment of harmful elements in Shanxi coal are coal accumulation environment,sedimentary source properties and magmatic hydrothermal activity.It is suggested that the occurrence of harmful elements in coal should be further studied in order to improve the effect of coal washing and improve the washing method.The harmful elements should be fixed at the same time,and the secondary pollution should be prevented and reduced.In the use of useful elements extracting from fly ash,technical,economic and environmental indicators should be comprehensive evaluated.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 131K]

  • Study on recleaning technology for dense medium middlings

    Li Xuanhuai;Tunlan Coal Preparation Plant,Xishan Coal Electricity Group Co.,Ltd.;

    In view of the coking coal resources depletion and the increase of the content of thick coal seam,the dense medium middlings of Tunlan coal preparation plant was used as the research object to save the scarce coal resources. The study of coal quality analysis and crushing dissociation was employed to explore the relationship between crushing grain size and middlings dissociation. The TBS separation of middlings crushing and flotation technology was proposed,and its economic benefit was analyzed. Results indicate that coal preparation plant could increase the income of 11.520 5 million yuan a year if utilize coarse coal slime with 3-0.5 mm by TBS separation process and the fine slime by flotation under 0.5 mm.It proves the feasibility of recleaning for dense medium middlings.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 167K]

  • Characteristics of rapid pyrolysis of Shengli brown coal

    Xu Xiuqiang;Ding Li;Guo Qihai;Zhao Xiaonan;Shenwu Technology Group Co.,Ltd.;Pyrolysis and Quality Engineering Technology Research Center of Low Rank Coal and Organic Waste in Beijing;

    To investigate the influence of pyrolysis temperature on pyrolysis product grade and residual volatile,the effect of temperature from 400 ℃ to 900 ℃ on the yield of pyrolysis product,gas composition,micro-structure of char and the residual volatiles were examined in a 10 kg/h self-made experimental equipment for rapid pyrolysis of brown coal using Shengli brown coal as a raw material.Results show that char yield decreases and gas yield increases gradually with temperature.The tar yield increases firstly and then decreases,and reaches a maximum at 700 ℃.The CO_2 in pyrolysis gas decreases slowly while H_2 and CO increases with temperature.Besides,with rising of temperature,the volatiles release continuously,which leads to a reduction of O-containing functional groups as well as the highly active small aromatic ring matters.Less residual volatiles and more fixed carbon are left in char when it is higher than 700 ℃,which can meet the requirement of calcium carbide coke.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 214K]

  • Study on gasification kinetics of char-CO2 reaction by iso-conversional method

    Zeng Mei;Zhao Meng;Xu Hongdong;Zheng Yalan;Zhang Yu;He Genliang;Men Changgui;Xi'an Origin Chemical Technologies Co.,Ltd.;The Northwest Research Institute of Chemical Industry;

    In order to obtain the reliable kinetics parameters of char-CO_2 gasification,the kinetics were evaluated by Flunm-Wall-Ozawa( FWO) iso-conversional method.A series of gasification experiments were carried out at three different heating rates of TG.The reaction activation energy were calculated under different carbon conversion ratio,the gasification mechanism was analyzed by using principal curve,and the data obtained from the iso-conversional method were examined by fitting method.Results show that the variation of the gasification activation energy present little change(( 228.25 ±5.22) k J/mol) at different carbon conversion rate( α ranges from 0. 2 to 0. 8).This paper suggestes that char-CO_2 gasification process is homogeneous model,and the experimental curves are close to the model curve.The model is satisfying with the kinetics model commonly used in coal gasification.The difference of the gasification activation energy between fitting method and iso-conversional method is 0.74 k J/mol,therefore,the iso-conversional method is feasible for kinetics study of char-CO_2 gasification.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 235K]

  • Prediction of acentric factor of direct coal liquefaction oil by artificial neural network and group bond contribution coupled model

    Mao Xuefeng;Research Institute of Coal Chemistry,CCTEG Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;National Energy Technology and Equipment Laboratory of Coal Utilization and Emission Control;

    In order to explore a new method to predict the acentric factor of narrow fractions from direct coal liquefaction oil( DCLO),artificial neural network and group bond contribution coupled model( ANN-GBC) were established. The coupled model used 45 group-bonds and atmospheric boiling point( Tb) of DCLO as input parameters,the relevance between acentric factor and molecular structure of 15 coal liquefaction narrow fractions was investigated.By calculating the acentric factors of 20 model compounds,the ANN-GBC model presents good simulation calculation function,and the average relative error between the calculated value and the theoretical value is less than2. 5%.These comparative data show that acentric factor increases with the increasing of the distillation temperature.The predicted value of ANN-GBC model is higher than that from Watanasiri and NEDOL.In terms of <380 ℃ fractions,ω is less than 1,and the deviation is relatively small,nevertheless,the deviation of > 380 ℃ fractions is larger. The > 420 ℃ fraction can be qualitatively and quantitatively analyzed,because only 20% substances is derived from coal liquefaction narrow fractions. In addition,the actual differences in specific substances could induce a larger deviation,the deviation is very large.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 233K]

  • Research on the gas-solid two-phase movement behavior in turbulent flow region of fixed bed slagging gasifier

    Zou Zhenjiang;Chen Guifeng;Dong Weiguo;Chao Junnan;Wang Xue;Guo Chenchen;China Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;

    In this paper,the relationship between the slag gasifier nozzle angle,nozzle diameter,jet velocity and turbulent flow region depth in the fixed bed gasifier were investigated.The study was carried out on a two-dimensional cold-state experimental model of industrial-scale gasifier established according to similarity theory.The gas velocity distribution in the granular bed was measured by the precision pitot tube,and the data was processed by dimensionless method.Results show that jet penetration depth and the quadratic of nozzle diameter are strongly related.Nozzle jet depth presents a trend of increase before decrease with the increase of nozzle angle.Jet depth is the largest when installing angle varys from 17° to 20°.The jet depth increases with the increasing of jet gas velocity.The dimensionless relation of gasification agent nozzle angle,jet velocity,nozzle diameter and turbulent zone depth are elucidated.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 281K]

  • Effect of high temperature on the performance of Fe-Cu-K-Si catalyst for Fischer-Tropsch synthesis in slurry phase

    Du Bing;Wang Tao;Liu Xiao;Hu Yunjian;Bu Yifeng;Men Zhuowu;National Institute of Clean-and-Low-Carbon Energy,Beijing;

    A Fe-Cu-K-Si catalyst for Fischer-Tropsch synthesis was prepared,and the effect of high temperature on the catalyst performance in slurry phase was investigated.Compared with the effect at 265 ℃,the results indicate that the slurry phase level decreases by 22%but keeps stable at 320 ℃.CO conversion rate is increased by 20%,but the selection of CO_2 is lower by 2%.In the meantime,CH_4 and C_2-C_4 hydrocarbon selection are improved respectively by 4.7% and 11.72%,C_2-C_4olefin-alkyl ratio is 1.99 higher,likewise,the C_3 and C_2hydrocarbon olefin-alkyl ratio are 3.37 and 0.87 higher respectively.The experimental data indicates that when the reaction temperature is raised to 320 ℃,the selectivity of C_(5+)hydrocarbons is decreased apparently,even though CO conversion rate,C_1-C_4 hydrocarbon selection and olefin-alkyl ratio are increased obviously.Therefore,the reaction temperature should be controlled depending on the actual needs of hydrocarbon products distribution in industrial production.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 239K]

  • Simulation on high temperature flue gas drying and rotating tube drying processes of lignite using Aspen Plus

    He Yicong;Research Institute of Coal Chemistry,CCTEG Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;

    In order to study the features of high temperature flue gas drying and rotating tube drying,the two processes were simulated using Aspen Plus.Energy balancing method and exergy analyzing method were employed to analyze the energy utilizing efficiency of these two drying systems.Results show that the Aspen Plus can accurately simulate the high temperature flue gas drying and rotating tube drying processes.When the flue gas temperature is 750 ℃ and the vapor temperature is 203. 1 ℃,the heat utilizing efficiency of rotating tube drying is 71. 27%,which is 4. 04% higher than the flue gas drying proces,while,the exergy utilizing efficiency of rotating tube drying is87. 68%,which is 49.33% higher than high temperature flue gas drying. The heat utilizing efficiency of high temperature flue gas drying and rotating tube drying will increase with the rising of temperature of drying medium. On contrast,the exergy utilizing efficiency will decrease with the increase of temperature of drying medium.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 184K]

  • Distribution of gas holdup in slurry bubble column reactor

    Zhang Fengbo;Bu Yifeng;Xu Ming;Men Zhuowu;National Institute of Clean-and-Low-Carbon Energy,Beijing;

    In order to study distribution law of gas holdup in slurry bubble column reactor,the gas holdup in slurry bubble column reactor was studied under cold-state experiment with the aid of an air-liquid paraffin-alumina microspheres 3-phase system.The effects of superficial gas velocity and solid concentration on total gas holdup were investigated using differential pressure transmitter.The distribution of local gas holdup under different operating condition was also systematically elucidated by means of an optical fiber probe.Based on these experimental results,the design of an industrial slurry bubble column reactor was also proposed.Results show that total gas holdup increases with increasing of superficial gas velocity,while the addition of solid fine particles slightly decreases the total gas holdup.In the bottom area of the reactor,a significant effect of gas sparger on gas holdup distribution presents.Such effects partly decrease with the increasing of superficial gas velocity.In the middle and upper area of the reactor,the gas holdup shows higher in the middle,while lower at the edge distribution status along the radial direction,which means there is no obvious effect from the gas sparger in this area.For an industrial FischerTropsch synthesis reactor,the filtration system should be better located at the area near the middle/upper reactor wall,with the operating superficial velocity higher than 0.12 m/s.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 226K]

  • Study on the network of dibenzothiophene hydrogenation using phosphide catalyst

    Huang Peng;Research Institute of Coal Chemistry,CCTEG Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;

    In order to research the network of dibenzothiophene hydrogenation using phosphide catalyst,molecular sieve SBA-15 was used as the supporter to prepare the nickel phosphide catalyst by incipient impregnation method. The Ni/P mole ratio was 1. 25,and catalysts with different loading of nickel phosphide were characterized. Model compound dibenzothiophene with 1% concentration was used to conduct the hydrogenation experiment,the phosphide catalyst was evaluated on a 20 m L fixed bed hydrogenation equipment.The results show that compared with the ordinary commercial catalyst,phosphide catalysts have a higher conversion rate on diben zothiophene at low temperature,which could reach more than 80% at 280 ℃. The existence of quinoline presents a strong inhibitory effect on the hydrogenation of dibenzothiophene,and thus the conversion rate is reduced from 100% to 70% at 320 ℃.The selectivity of biphenyl and cyclohexylbenzene are very small,and the transformation of dibenzothiophene is almost entirely via the direct desulfurization pathway. The phosphide catalyst has higher hydrogenolysis capacity and better direct desulfurization selectivity.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 238K]

  • Combustion characteristic of pulverized coal in hypoxic atmosphere

    Cheng Xiaolei;China Coal Research Institute Company of Energy Conservation;State Key Laboratory of Coal Mining and Clean Utilization;National Energy Technology & Equipment Laboratory of Coal Utilization and Emission Control;

    In order to investigate the effect of CO_2 component to combustion in the hypoxic atmosphere,while realizing low NOxcombustion of pulverized coal,experiments of coal combustion in hypoxic atmosphere were conducted on thermogravimetric analyzer.To simulate the real reaction atmosphere,effects of different O_2/CO_2 mixing ratios and heating rates to the combustion characteristic were conducted.The results show that a competitive relation is found between combustion and gasification of coal in the O_2/CO_2 mixing atmosphere,when the reaction temperature is below 1 000 ℃.Higher CO_2 content will improve the restriction level of pulverized coal combustion by gasification reaction with coal.Lower O_2/CO_2 mixing ratio will restrain the burnout of coal,while the ignition temperature is hardly impacted by the CO_2 content.A heating rate improvement of 10 ℃/min to 20 ℃/min will apparently enhance the ignition and combustion stability of coal,while improvement of 20 ℃/min to 30 ℃/min has no such influence.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 216K]

  • Effect of temperature on the preparation of mesophase pitch from coal liquefaction pitch

    Chang Hongyan;Zhang Yuanxin;Li Kejian;Zhang Xuwen;Cheng Shifu;Shanghai Research Institute,China Shenhua Coal to Liquid and Chemical Co.,Ltd.;National Engineering Laboratory for Direct Coal Liquefaction;

    In order to prepare high quality mesophase pitch,coal liquefaction pitch was used as raw material and mesophase pitch was prepared at different temperature.Polarized light microscopy,infrared spectroscopy,X-ray diffraction,thermal gravimetric analyzer were used to test and characterize the mesophase pitch.Results show that temperature has a significant influence on the pitch yield,morphology and texture of mesophase pitch.With the increasing of temperature,the yield of H,S and mesophase pitch content decrease,while the residual carbon rate increases.With the mesophase spherule size increasing and the gradual emergence thawing,the pitch eventually form wide range mesophase.The content of polycyclic aromatic hydrocarbons,aromatic hydrocarbons in coal liquefaction pitch increase significantly,however,the alkane component significantly decreases. The amorphous area reduces as a result,arrangement and orientation of the molecules become well distribution.Lower thermal polymerization temperature( 410-420 ℃) and longer reaction time are used to optimize the direction of the reaction,so as to achieve the purpose of preparing high quality mesophase pitch.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 306K]

  • Study on chemical demulsification and desalination of coal pyrolysis tar

    Ma Bowen;Research Institute of Coal Chemistry,CCTEG Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;

    In order to reduce the corrosion of inorganic salts from emulsion water in the coal tar to the fractional distillation condenser and accelerate the separation of coal tar from water,the desalination test of coal pyrolysis tar was carried out by chemical demulsification. The feasibility of chemical demulsification of coal pyrolysis tar was discussed.The effects of test conditions such as demulsifier type,demulsifier addition,water addition,desalination temperature and residence time on the desalination of coal tar were investigated.The results show that the self-made polyether demulsifier has better desalination effect.The addition of demulsifier and water are with amount 100×10~(-6) and 15%respectively,and the desalination temperature is 110 ℃,the salts content in the oil are obvious decreased. The residence time has little effect on the result within a certain range.Therefore,the self-made polyether demulsifier,which is mainly attributed to the strong interaction with special structure of asphalt in coal tar,demonstrates better desalting effect comparing with the other two kinds of widely used demulsifier.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 163K]

  • Compounding reagent for medium-low temperature coal tar dewatering

    Zhang Ju;Liu Zhiling;Zhang Yuan;Liu Qiaoxia;Zhang Wei;Research Institute of Shaanxi Extended Petroleum ( Group) Co.,Ltd.;

    In order to solve the issue of pipe and flange burst caused by water during the deep processing of coal tar,the effects of dehydration reagent ratio,dosage,dehydration temperature and stirring time on dehydration efficiency were investigated. The dehydrating reagent could reduce the water content of coal tar to below 3%.The optimum conditions are I and J mixture ratio of 2 ∶ 3,the amount of dehydrating agent is 5×10~(-4),the dehydration temperature is 60 ℃ and the stirring time is 1 h.The test results show that the dehydrating reagent has little effect on the quality of coal tar,moreover,it has good dewatering and desalting capacity.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 125K]

  • Effect of coal blending on ash-fusion and viscosity-temperature characteristics

    Liu Shuo;Zhou Anning;Yang Fusheng;Jing Yunhuan;Shaanxi Institute of Technology;School of Chemistry and Chemical Engineering,Xi'an University of Science and Technology;Shenhua Ningxia Coal Group Coal Chemical Company;

    The extremely low fusion temperature and low viscosity of coal ash were the critical factors influencing on the long-period stable operation of large-scale entrained-flow gasifiers in Ningdong coal chemical industries,therefore the effect of coal blending on ash-fusion and viscosity-temperature characteristics were systematically investigated by XRD,Factsage,ash-melting tester and high temperature rotary viscometer,respectively.Results show that the coal blending ratio is nonlinear with ash-fusion and viscosity-temperature characteristics.The blending of SM coal and MK coal with a ratio of 2 ∶ 8 achieving the ash-fusion temperature of 1 300 ℃ and viscosity 5 Pa·s basically satisfies the operational requirements of Texaco gasifier.The main mineral with high melting point in the blended coal ash is quartz.It can be concluded that the blending of coals can effectively improve the ash-fusion and viscosity-temperature characteristics.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 230K]

  • Process simulation of extraction and removal of phenol from coal chemical wastewater

    Fu Churui;Qu Sijian;Dong Weiguo;Gao Minglong;Wang Jikun;China Coal Research Institute;State Key Lab of High Efficient Mining and Clean Utilization of Coal Resources;

    In order to improve the efficiency of extraction and removal of phenol from coal chemical wastewater and reduce the environmental pollution from wastewater discharge,Aspen Plus was used to optimize the extraction and de-phenol removal process. The logistics data used in simulation was from actual compositions of coal chemical wastewater,and its feed flow was 100 t/h,at temperature of 40 ℃ and pressure of 0.1 MPa.The parameters of the extraction column,the solvent recovery column and the solvent stripping column were adjusted by using the UNIQUAC and NRTL activity coefficient models respectively. Results show that the total phenol concentration of the wastewater is reduced from 18 600 mg/L to below 400 mg/L,and moreover the phenol concentration is reduced from 14 000 mg/L to below50 mg/L,the recovery rate of extraction agent is over 99%,when the parameter is set as follows: the extraction tower series and solvent ratio of extraction column are 6 and 1 ∶ 4,respectively,the theoretical plate numbers and feed position of the solvent recovery column are 10 and the fifth tray respectively,as well as the theoretical plate number and feed position of the solvent stripping column are 5 and the first tray.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 301K]

  • Experimental study on conduction induction separation of fly ash

    Wu Haiyang;Zhang Jun;Zhang Canqiang;Fan Rendong;Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Southeast University;Jiangsu Electric Power Design Institute;

    To improve the comprehensive utilization of fly ash,the fly ash separation experiment was conducted on a conductive induction charging test bed in this paper.By changing the parameters of the plate type,the plate voltage,the plates spacing and the particle size,as well as the factors of sorting effect were studied,and comparative analysis of sorting products were carried out.Results show that the separation performance of the concave electrode plate is better than the convex electrode plate. With the increase of voltage,the ignition loss of fine ash shows an ascending tendency and decreases afterwards.The smaller particle size possesses lower loss on ignition and leads to difficult in sorting.The increase of plate spacing will weaken the strength of the electric field and affect the movement of particles.The effect of separation is ideal to coarse ash with particle size >48 μm,but it is relative poor to fine ash.After sorting,the maximum ash loss is 21. 89%and the recovery rate of carbon can reach 53. 02%.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 316K]

  • Low NOx improvement scheme of supercritical swirling combustion boiler

    Wei Zengtao;Cheng Zhihai;Guo Yonghong;Shanghai Power Equipment Research Institute;College of Enegy and Mechanical Engineering,Shanghai University of Electric Power;School of Energy,Power and Mechanical Engineering,North China Electric Power Universtiy;

    In order to reduce the NOxconcentration entering the SCR( selective catalytic reduction),a 600 MW supercritical boiler was tentatively retrofitted to be a low nitrogen burner.Primarily,the factors causing high concentration NOxemission were investigated.Accordingly three kinds of retrofit schemes were made by a numerical simulation,and eventually,an optimized implementation scheme was selected.The detailed retrofit scheme is maintaining the original burner number and position,reducing the primary air flow area( constant wind speed) and obtaining the main burner region of excess air coefficient being 0.85.The replacement of advanced low NOxburners are recommended,and only 6 separation overfire air outlets( initial elevation 34.724 m) are left in the two sides of the wall,and a layer of separated overfire air( 12 nozzle) is set at the elevation of 39.350 m.Over a period of operation after retrofitting,the average concentration of NOxentering SCR is about 400. 7 mg/m~3,which is about 12. 8% higher than the numerical simulation results indicating the appropriate significance of numerical simulation.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 359K]

  • Study on the waste heat utilization system of 300 MW CFB boiler

    Bai Tao;Jin Zhiping;Wang Yanling;Du Hailing;Liu Wenhui;Department of Power Engineering,Shanxi University;

    In order to solve the problem of excessively high temperature of exhaust gas,a low pressure economizer was installed in the tail flue to reduce the fuel gas temperature and increase the thermal economy of the unit.The layout schemes were proposed according to the design discipline and parameter requirement by systematically considering the sulfur contamination,abrasion of tube wall,and enthalpy rise constraint among the heat regenerative systems. The thermal economy of proposed schemes was evaluated using equivalent enthalpy drop method.The results show that scheme 3 achieves higher thermal economy than others.It can reduce the coal consumption to 1.517 g/k Wh at rated load.The low pressure economizer presents better energy saving effect,and it can be beneficial as energy saving reference for other same type units.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 205K]

  • Analysis of slagging and fouling characteristics in a purely burning zhundong coal boiler

    Bai Yang;Shenhua Guoshen Technical Research Institute;

    In order to elucidate the problem of severe slagging and fouling during burning Zhundong coal,150 t/h boiler in Xinjiang Yihua company was used to carry out the assessment on all-Zhundong coal operation.The fouling configuration and morphology of water wall panel,super-heater,low temperature tube,and bottom ash were traced,and the slags from different positions were analyzed. The results show that the boiler suffers seriously slagging and fouling during entirely burning Zhundong coal.The slagging and fouling are caused by various forms of Na-bearing materials,such as sodium chloride and sodium oxides as well as elemental sodium released from coal and accumulated on the high temperature metal surface,reacting with SO_2、Fe_2O_3 to produce sulfates.The Fe-bearing minerals will decompose and combine with CaO,Al_2O_3 etc to produce low temperature eutectics.Such eutectics can decrease the ash melting temperature and accelerate the slagging and fouling propensity of Zhundong coal. Moreover,Ca and water in coal promote the accumulation of duster in the low temperature tube.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 303K]

  • Application and improvement of diaphragm filter press in direct coal liquefaction project

    Du Xiaojun;Ordos Coal to Liquid Branch,China Shenhua Coal to Liquid and Chemical Co.,Ltd.;

    In view of the unstable operation problem of diaphragm filter press in catalyst preparation plant of Shenhua direct coal liquefaction project,the diaphragm filter system was modified on the basis of analysis on the diaphragm filter press system,principle and operation.Results show that the filtering slurry leaking material,filtrate leaking,pull plate deformation failure,frame,the filter cloth inspection car taking too long,are the main factors influencing the diaphragm filter press and stable operation.By using the filter press thrust plate on the takeover of compensator,increasing the closed gas water separator,leveling rail and chain wheel bearings and adopting more strong point hole in the diaphragm filter plate the press system are modified. After modification,4 filter machine faults are less,maintenance time is shortened,strengthen equipment and stable operation ability are increased,filtrate flow into the filter cake is reduced. The filter press load has been able to meet the producing load of direct coal liquefaction project requirements. Stable operation of catalyst plant basically meet the requirement of direct coal liquefaction project operation and achieved better effect.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 127K]

  • Research and application of tower desulfurization technology for coke oven gas

    Gao Xiang;Shanxi Coking Group Co.,Ltd.;

    In order to achieve the SO_2 emission being no more than 50 mg/m~3 in coke oven gas according to the " GB 16171—2012" standard in coking chemical industry,Shanxi Coking Group Limited company updated and reconstructed the desulfurization system from 2014 to2015.The vertical space was considered adequately used for shortening the process,because of the limit of place and adjacent to benzene unit.The PDS tower desulfurization technology was adopted during technical reforming.The technology had the advantages of short process,small footprint,less investment,etc. Results show that the H_2S concentration in coke oven gas can be reduced to less than 20 mg/m~3,which can completely meet the requirements of national environmental protection.

    2017 03 v.23;No.109 [Abstract][OnlineView][HTML全文][Download 207K]
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