2018年04期目次

  • Status and prospect of separation methods and composition characteristics of coal tar

    GU Xiaohui;Coal Chemistry Branch of China Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;

    In order to promote the deep processing of coal tar to the direction of large-scale,clean,refined and environment-friendly,route of typical coal tar processing methods were studied. The present situation of the main separation methods of coal tar components was described in the aspects of distillation,membrane separation,crystallization,and so on. The properties of typical components in coal tar were analyzed,including the contents,types and molecular structure characteristics of acid and alkali components,phenolic components,aromatics components,salt base components and heavy components in coal tar. Combined with the processing methods of coal tar,the characters and shortcomings of the development of the industry were put forward. Four typical coal tar processing methods includes traditional high temperature coal tar processing route,medium and low temperature coal tar hydrotreating route,coal tar high added value chemical extraction and hydrotreating process route.Processing route of comprehensive utilization of coal tar is better processing and utilization routes.According to development and optimization of coal tar deep processing route,it is generally preferable to extract high added value chemicals from coal tar,and then further processing of residual components is an effective complement and upgrading to coal tar utilization.The basic research of coal tar should be strengthened,and green and efficient comprehensive processing technology for coal tar should be developed.The multi-angle and multi-level systematic research of different kinds of coal tar should be research,and then gradually establish the basic database of coal tar.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1730K]

  • Research on the characteristic and application of semi-coke

    LIU Jing;HE Xuanming;LI Cuihua;FENG Dongzheng;KE Ping;Hubei Coal Conversion and New Carbon Materials Key Laboratory;School of Chemistry and Chemical Engineering,Wuhan University of Science and Technology;

    In order to realize the classification and utilization of coal and improve the utilization efficiency of semi-coke resources,the application and research progress of semi-coke in China was introduced,and the summary of its application in calcium carbide industry,power plant,metallurgical industry,fertilizer industry,wastewater treatment and preparation of electrode materials were summarized. At last problems and development direction of semi-coke were proposed.The results show that semi-coke can be applied to various industries,and process index or equipment should be changed with the difference of material properties.Semi-coke enterprises should upgrade the technology and equipment conditions so as to raise the level of industrialization and added value of product.Semi-coke can be used as raw material mixed with anthracite coal and bituminous coal in calcium carbide industry,power plant,metallurgical industry.Based on characteristics of semi-coke powder and the preparation process of coal based activated carbon,high performance activated carbon made of semi-coke is prepared by microwave heating and phosphoric acid activated,so that the waste of resources is turned into treasure. In the future,the process conditions and activation mechanism of activated carbon prepared from semi-coke power should be explored to achieve more efficient use of semi-coke powder.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1115K]

  • Present situation and forecast on production technology of reactive coke

    YIN Mengmeng;ZHANG Yanpeng;TIAN Bin;QIAO Yingyun;TIAN Yuanyu;Laboratory of Low Carbon Energy and Chemical Engineering,Shandong University of Science and Technology;School of Chemical Engineering,Northwest University;Laboratory of Heavy Oil Processing,China University of Petroleum (East China);

    In order to solve the problem of high value utilization of semi-coke power,reactive coke was obtained through molding technology of semi-coke powder,and production technology of reactive coke was analysed.Technology integration and matching of binder,molding process and equipment were reviewed,and existing problems and development direction in the future were proposed. Material of reactive coke is semi-coke power,so that it can effectively solve the problem of powder form pulverized coal pyrolysis and upgrading,and achieve high value utilization of semi-coke power( below 5 mm). Rreactive coke can be used directly to produce calcium carbide,take part in chemical reaction of puddling and silicon iron,which can increase heat and mass transfer area and reaction rate,realize in situ contact of reactant and cyclic utilization of material.Combined with technology of binder,molding process and gradation technology,high strength reactive coke can be obtained with less adhesive and reduce cost. The reactive coke technology can improve reaction rate and save energy combing molding technology with calcium carbide,puddling and silicon iron.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 2768K]

  • Status and prospect of quality upgrading and utilization technology by pressure swing adsorption of low concentration coal bed methane

    LI Xuefei;Coal Chemistry Branch of China Coal Research Institue;State Key Laboratory of Coal Mining and Clean Utilization;National Energy Technology & Equipment Laboratory of Coal Utilization and Emission Control;

    In order to increase the utilization rate of low concentration coal bed methane,the quality upgrading and concentration technology of low concentration coal bed methane by pressure swing adsorption and special adsorbent were developed.Laboratory tests and pilot scale tests were carried out successively.The concentrating and upgrading technology of low concentration coal bed methane by pressure swing adsorption had been formed,and the industrial demonstration applications were carried out.The results show that the separation coefficient of the special adsorbent for methane and nitrogen is 4.0,and the abrasion resistance is 99%.The low concentration coal bed methane with30% methane content and 12%-15% oxygen content was safely transported,compressed and purified and concentrated by pressure swing adsorption.The methane content of the product gas is increased to more than 90%,and the oxygen content of the product gas is decreased to below 1%.The concentrating gas can be used for the production of CNG or LNG.After the technology promoted,the utilization problems of the low concentration coal bed methane when the methane volume fraction higher than 25% can be effectively solved.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 2476K]

  • Distribution characteristics of trace elements in Jurassic coal in Northwest China

    WANG Hua;ZHANG Guotao;BAI Ni;Yulin College;

    The content of trace elements in coal is one of the reference standards for coal clean utilization,and more than 1 300 Jurassic coals from Northwest,China were analyzed.It is concluded that the total content level of trace elements in the Jurassic coal in the northwest is low,and only a few trace elements are obviously enriched in local areas in Northwest Jurassic coal,such as Ba in Ordos basin,U and Mo in Yili basin,V,Co and Y in Junggar basin and W in Qaidam basin.The total trace elements content in each basin shows the trend of Qaidam basin>Junggar basin>Yili basin>Ordos basin>Tarim basin.In the Northwest of China,the total content of trace elements in early Jurassic is higher than that in middle Jurassic.The research results lay a theoretical foundation for the clean utilization of Jurassic coal in Northwest China.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 2838K]

  • Thermodynamic properties of minerals during the preparation of ultra-clean coal

    YIN Hongqing;Yankuang National Engineering Research Center of Coal Slurry Gasification and Coal Chemical Industry Co.,Ltd.;

    In order to improve the removal efficiency of minerals in different coals,the mineral composition of different coals was tested by AMICS system.The reaction process of different minerals during the preparation of ultra-clean coal( UCC) was discussed.Using HSC thermodynamic database software,the reaction thermodynamic data( delta H,delta S and delta G) and equilibrium constant K of the main minerals in UCC preparation were calculated,and effect of temperature on dissolution reaction of related minerals was determined. The results show that the minerals in coal mainly include kaolinite,dolomite,pyrite,quartz,pyrite and dolomite. Different kinds of coal have different minerals.According to the mineral composition and thermodynamic characteristics,the reaction temperature and the amount of acid and alkali in coal should be adjusted by chemical method to improve the mineral removal efficiency and prepare high purity UCC. Hematite and calcite in coal react with sulfuric acid easily and get rid of easily. The lye digestion reaction of kaolinite,silica,bauxite and pyrite in coal should be appropriately increased.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1726K]

  • Experimental study on fluidized separation of pyrite in coal-mill refuel

    MENG Qi;LI Guichun;College of Mining Engineering,Heilongjiang University of Science and Technology;

    In view of the serious wear of coal mill caused by pyrite and other materials in coal mill recharge and the increase of desulfurization cost in power plant,the fluidization principle was put forward to separate coal mill return material by removing pyrite and other substances.To achieve the purpose of efficient energy saving,economic and environmental protection,the separation experiment was carried out on a fluidized bed with a coal mill in Huaneng Power Plant.The influence of various factors on the separation efficiency was studied.The results show that the fluidization effect is ideal,pyrite is enriched below 0.22 mm,the total sulfur content of heavy product is more than 15%,and ash content is up to 72.3%.The removal of most noncombustible materials such as pyrite can provide certain theoretical data for the economic operation of power plant. When the separation rate is 15. 4%,the combustible recovery is 87. 79%. If the particles less than 0.22 mm are removed from the heavy sample,the combustible recovery body can be close to 100%.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 2342K]

  • Ultrasonic-aided flotation decarbonization of fly ash

    LI Hailan;WANG Fan;WANG Lufeng;College of Vanadium and Titanium,Panzhihua University;

    In order to solve the high carbon content problem of fly ash,the flotation decarburization test on fly ash was carried out with the aid of ultrasonic.The effect of the main factors on the decarbonization of fly ash was studied by a single factor experiment,and then the full flotation process test of " one coarse four fine one sweeping" was conducted.The results show that in single factor experiment,when the pulp concentration is 106.7 g/L,No.2 oil dosage is 976.5 g/t,kerosene dosage is 441.9 g/t,ultrasonic treatment time is 2 min,flotation time is7 min,the flotation effect is the best,the ignition loss and recovery rate of concentrate is 59.65% and 68.41%,respectively.Ultrasonic can effectively improve the flotation effect of fly ash. " One coarse four fine one sweeping" test obtains fine carbon,the ignition loss and recovery rate are 75.96% and 66.70%,respectively,achieving the effective recovery of fly ash.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1515K]

  • Experimental study on floatation test of difficult floated coal

    LU Zhiqiang;DIAO Hairui;LI Caixia;ZHANG Tianye;China Coal Technology & Engineering Group Tangshan Research Institute Co.,Ltd.;College of Mining Engineering,Liaoning Technical University;

    Inorder to improve flotation efficiency of difficult floated coal in Yicheng preparation plant,mineral component,property and floatability law of No.3 coal slime were analyzed,and the optimum condition was obtained.Result shows that the contents of Si O2 and Al2 O3 reach 60.01% and 25.14% respectively,which determines the floatability.The dominant grain size less than 0.074 mm accounts for 51.11%and its ash accounts for 38.84% indicating high content of slime and impeding the flotation.Through single factor variation method,the optimum flotation condition is obtained,namely,collector dosage of diesel 270 g/t,foaming agent dosage of octanol 60 g/t,feed concentration of the flotation 120 g/t,impeller speed 1 750 r/min,charge speed of 0.19 m3/( m2·min),scraper speed of 15 r/min,and scraping time 2 min.Under this conditions,the clean coal yield can reach 34.57% with ash of 10.5%,which accords with the ash index of clean coal and also promotes clean coal yield.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1091K]

  • Selection and application of additive for high concentration low rank coal water slurry

    LYU Xiangyang;China Coal Technology & Engineering Group Clean Energy Company Limited Department;Beijing Chengcheng Coal Science And Technology Development Company Limited Department;

    In order to screen and prepare additives suitable for the preparation of high-concentration coal-water slurry of low rank coal,long-flame coal,slightly-caking coal and lignite were selected as test materials,and additive MK-1 with NSF as the main component for high concentration coal water slurry developed by independent research and development,commercial available additive AYK and AZM with sodium lignosulfonate as the main component were selected for the dry test in the laboratory,the wet method magnification test and the industrial trial,to prepare high concentration coal water slurry.Three-peak-fractal sizing process was used in the study.The high concentration coal-water slurry was prepared after adding MK-1,AYK and AZM respectively,and the slurry properties were analyzed and compared.The results show that the effect of MK-1 additive is better than AYK and AZM for low metamorphic coal.Using MK-1 additive,the highest concentration of Shaanxi long flame coal( ZM),Henan long flame coal( LX),Xinjiang lignite( YL),and Xinjiang weak coal( YK) are 66. 58%,65. 35%,63. 35% and 54. 19%,respectively.Under the same concentration and viscosity,the MK-1 additive of MKCC is less than 50% of the commercial AZM additive,which can significantly reduce the economic cost. By comprehensive comparison,it is concluded that the MK-2 additive is more suitable for the preparation of high concentration coal water slurry with low rank coal.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1255K]

  • Experimental study on flash pyrolysis of lignite with different moisture contents

    SHI Xiaoli;CHEN Shuimiao;SUN Baolin;MEI Lei;ZHAO Yanbing;ZHANG Hongwei;WANG Qinya;XIAO Lei;WU Daohong;Beijing Shenwu Power Technology Co.,Ltd.;Shenwu Technology Group Co.,Ltd.;

    In order to study the effect of moisture on pyrolysis characteristics of lignite,the pyrolysis experiment of Indonesia lignite with different moisture contents were carried out on the Shenwu regenerative flash pyrolysis furnace.Results show that as the increase of moisture contents of lignite,the pyrolysis gas yield increases gradually,the content of H2 and CO2 in the pyrolysis gas increase,and the contents of CH4 and CO decrease.When the moisture content was 24.01%,the pyrolysis gas yield reaches the maximum value of 45. 40%. As the increase of moisture contents of lignite,tar yield decreases gradually,the light components in tar increase and reach the maximum 69. 30%,When the moisture content is 24. 01%.The pyrolysis wateryield increases gradually,and when the moisture content is 24. 01%,the pyrolysis wateryield is 10. 60%. When the moisture contents of lignite increases from 5. 60% to 24. 01%,the yield of thechar decreases from56. 20% to 42. 50%,and the change on calorific value of char is not obvious. Pyrolysis energy consumption gradually increases,and when moisture contents increased from 5. 60% to 24. 01%,energy consumption increases from 1.77 MJ/kg to 3.26 MJ/kg.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1555K]

  • Pyrolytic characteristics of Shendong coal and feasibility analysis of semi-coke used in pulverized coal injection

    TAN Jing;ZHU Chuan;China Coal Research Institute Company of Energy Conservation;State Key Laboratory of Coal mining and Environment Protection;National Energy Technology & Equipment Laboratory of Coal Utilization and Emission Control;

    In order to realize deep processing and utilization of Shendong coal,thermogravimetric analyzer and tubular pyrolytic furnace were used to analyse pyrolytic characteristics of Shendong coal. Feasibility of semi-coke used in pulverized coal injection( PCI) were also conducted,and new path ways of usage of semi-cokes were proposed.The results show that qualities of Shendong coal with high tar yield( 8.15%) are excellent for low-temperature pyrolysis.The yield of coal tar is highest with lower ash in 550 ℃,and distillation temperature of more than 50% samples is less than 350 ℃. The contents of CH4 and CO2 decrease while H2 and CO increase in pyrolysis gases when temperature increases.The yields of pyrolysis water are basically kept at 16%. The injection characteristics of semi-coke are equal to the main injection coals used,so it is suitable for PCI.The semi-coke undergone mild pyrolysis could be used in PCI directly.It is graded utilized for semi-coke after tars extracted.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1507K]

  • Co-gasification characteristics of Jincheng anthracite and poplar sawdust

    WANG Shan;ZHOU Min;School of Chemical Engineering and Technology,China University of Mining and Technology;

    In order to analyze the influence of biomass on gasification of Jincheng anthracite,Jincheng anthracite and poplar sawdust were used as experimental objects to study the co-gasification characteristics of anthracite,demineralized anthracite and sawdust in the atmosphere of CO2.The influence of the blending ratios of poplar sawdust,heating rate and demineralization of coal samples on the gasification process was investigated by thermogravimetric analysis.The results show that the blending ratio of biomass can reduce the co-gasification temperature of anthracite and demineralized anthracite,and the increase of blending ratio can significantly reduce the initial reaction temperature,the initial temperature of co-gasification reaction of demineralized anthracite is lower,additionally. Comparisons of two kinds of heating rate of 10 and 20 ℃/min,heating rate has certain effect on co-gasification process,that is,low heating rate startes gasification reaction at lower temperature,and high heating rate obtains the maximum value of weight loss rate.After the anthracite is de-ashed,the loss of minerals leads to the development of coal pore structure,the active site of biomass and gasification agent is increased,and the gasification reactivity is improved.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1718K]

  • Effect of alkali and alkaline earth metal on the gasification reactivity of gasified coke

    WU Linlin;ZHU Chuan;Coal Chemistry Branch of China Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;

    Alkali and alkaline earth metals are important catalysts for gasification reaction of gasified coke,and their catalytic effect directly affect the gasification efficiency of gasified coke.The gasification of mixtures of several alkali or alkaline earth metals with gasified coke and gasified coke with different proportions of Na_2CO_3 were carried out. Effect of catalyst type and dosage on catalytic effect of gasified coke gasification was studied.Results show that at 1 000 ℃ and 1 050 ℃,the catalytic activity has the tendency of K_2CO3>Na_2CO_3>Ca CO3,meanwhile at 1 100 ℃,the catalytic activity tendency changes to Na_2CO_3>K_2CO3>Ca CO3 because of high temperature release of catalyst and catalytic activity improvement of Na_2CO_3.The conversion rate of gasification coke carbon from high to bottom is 5% Na_2CO_3>1% Na_2CO_3>2% Na_2CO_3>0.5% Na_2CO_3>no Na_2CO_3.It is also found that the order of the catalytic activity,the maximum reaction rate and the reactivity index is in the same order as the conversion rate of gasified coke,which indicates that catalytic activity does not increase with the increase of addition proportion.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1724K]

  • Influence factors and slagging control methods of fixed bed slag gasifier

    CHEN Jiangming;Coal Chemistry Branch of China Coal Research Institute;State Key Laboratory of Coal Mining and Clean Utilization;Beijing Key Laboratory of Coal Based Carbon Materials;

    In order to ensure smoothly discharge of liquid molten slag produced by fixed bed slag gasifier,the effect of several factors including ash melting temperature,viscosity,mineral form of slag and the temperature distribution in slag pool on gasifer slagging were analyzed.Meanwhile,the effect of ash components( Si O2,Al2 O3,Fe2 O3,Ca O) in coal on ash melting temperature were analyzed,and the control method and effect of liquid molten slag discharge was put forward.The results show that the minimum ash melting temperature can be obtained under the conditions of Si O2/Al2 O3<3.0 and 30%-35% of Ca O content in the ash,and theminimum temperature can also be obtained under the conditions of Si O2>50%,Si O2/Al2 O3>3.0 and 20%-25% of Ca O content in the ash.Methods of slagging control include that,making liquid slag less than 10 Pa·s by changing the ratio of limestone,the nozzle flame temperature 1 700-1 800 ℃,slag temperature 1 450-1 550 ℃,the ratio of steam and oxygen 0.90-0.95 kg/Nm3,slag discharge pressure difference at 47-49 k Pa.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1397K]

  • Effect of extraction treatment on metal removal and combustion characteristics of Zhundong coal

    TU Yanwu;XIONG Zhibo;JIN Jing;NING Xing;ZHANG Lei;School of Energy and Power Engineering,University of Shanghai for Science and Technology;Key Laboratory of Flow Control and Simulation,University of Shanghai for Science and Technology;Huaneng Shidao Bay Nuclear Power Co.,Ltd.;

    In order to mitigate the influence of alkali metals amount on the slagging and the fouling for the Zhundong coal-fired boil,the effect of hydrothermal treatments( Water bath and Microwave assistant water bath) and extraction solutions( Water,Ammonium acetate,ammonium acetate/acetic acid mixture,acetic acid/hydrogen peroxide mixture) on the removal of alkali metals and combustion characteristics of Zhundong coal were investigated.The results indicate that the removal of sodium is 43. 1% after treating with water under water bath;while the reducing of calcium,magnesium and iron are less than that of sodium.Compared to water,the mixture solution of acetic acid and hydrogen peroxide could remove 90.1% of sodium and 31.9% iron under water bath. The microwave irradiation could achieve similar removal rate of metals within 15 min compared with the traditional hydrothermal treatment for about 20 h.Both the ignition temperature and the burnout temperature of Zhundong coal are decreased after the extraction of water; while its combustion characteristics is improved.However,the combustion characteristics of Zhundong coal turns worse after the extraction by ammonium acetate or the mixture solution of acetic acid and hydrogen peroxide.And the solid residue of coal after burning out decreases from 8.21% to about 2.91%-4.27% after extracted by these four solutions.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 3293K]

  • Competition property analysis of gas power generation coupled with CCSI technology

    REN Jian;LI Dapeng;LI Qiming;WANG Ningbo;WANG Yongjuan;YAO Xiaohong;WANG Wei;YANG Fan;DANG Yu;Engineering Research Center for High-efficiency Utilization of Fossil Hydrocarbon Resource of Petroleum and Chemical Industry;Hydrocarbon High-efficiency Utilization Technology Research Center of Shaanxi Yanchang Petroleum (Group) Corp.,Ltd.;Huaneng Clean Energy Research Institute Co.,Ltd.;State Key Laboratory of Coal-based Clean Energy;

    To analyse the general advantages of the novel CCSI based coal-fuel-electric-power-chemical poly-generation mode in contrast to regular coal-fired power utility,assessment of economic & environmental advantages with respect to such kind of new coal utilization pattern was performed.The results demonstrate that,as for the subcritical coal-fired boiler upgrade mode,the overall revenue and coal value appreciation rate are 1 589.41-1 622.41 yuan,354.12%-363.60%,respectively,particularly,the profit appreciation rate increases from 4.87%-13.26% to 171.92%-182.43%.In the case of combining gas turbine power generation with CCSI process,the overall revenue,coal value appreciation rate,profit appreciation rate are 1 867.92-1 955.49 yuan,433.69%-458.71%,232.48%-245.45%,respectively.Moreover,the pollutant emission performance assessment reveales that,compared with conventional subcritical coal-fired power utility,as for the CCSI-subcritical coal-fired boiler upgrade mode,annual coal consumption can be reduced by 10 488-59 016 t/a,the annual environment cost can be cut to less than 1.386 6 million yuan from 4.624 3-6.361 7 million yuan.Compared with conventional ultra supercritical coalfired power utility,in the case of CCSI-combining gas turbine power generation process,the annual coal consumption can be reduced by about 98 952-143 664 t/a,and the annual environment cost can be cut to less than 0.343 9 million yuan.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1244K]

  • Analysis of operation performance on a 660 MW large capacity and high parameter unit in high altitude area

    HAO Bing;XU Yan;LI Yuheng;ZHANG Dongxu;LIU Jiali;TU Jingyi;FANG Shunli;Huaneng Xinjiang Luntai Thermoelectric Branch;Guodian Taizhou Power Generation Co.,Ltd.;Xining Power Generation Company,Qinghai the Yellow River Hydropower Company;Xi'an Thermal Power Research Institute Co.,Ltd.;

    The capacity of supercritical units that have already in operation in high altitude area are mostly 100-300 MW currently,and there exist many problems,such as low combustion efficiency and high subsidiary power consumption and serious equipment abrasion,thus they can't represent the most advanced design and operation level of boiler units in these area.In order to accurately grasp the design characteristics of high-capacity and high-parameter boiler equipment in these area and clarify the impact of main operating parameters on the economics of boiler operation,the heat load parameters of furnace and the design characteristics of the burner of the first 660 MW ultra supercritical unit boiler that has been put into operation in high altitude area in China was analyzed in this paper.The combustion optimization adjustment test and operation performance analysis were carried out,and the influence of key operation parameters on boiler combustion economy was obtained.The results show that the unit in high altitude area can achieve the same excellent combustion performance as the unit in plain area after the optimization of furnace heat load parameter and key operation parameters.The boiler efficiency will reach over 94% when the unit is full loaded,and the minimum oil-free stable load can reach 23%,which is comparable to that of the unit in plain area.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 140K]

  • Application of low-NOx combustion technology on pulverized coal industrial boiler

    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 study the low-NO_xeffect of air-staging technology on pulverized coal industrial boilers,air-staging low-NO_xcombustion experiment were carried out on a 40 t/h steam boiler.The influence of boiler load,air-staging ratio and air-staging arrangement on NO_xgeneration was studied.The results show that the initial NO_xemission of the boiler increases with the increase of boiler load when no air-staging method was carried out,and the low-NO_xefficiency of the low oxygen air combustion can reach to 15%.The air-staging method obviously reduces the initial NO_xemission of the boiler,and the NO_xdischarge in the flue gas is 175 mg/m3,and the CO content is 72×10-6. The closer air-staging position is to the furnace outlet,the more low-NO_xeffect is observed. In order to achieve the ideal low-NO_x effect,the staging air should have sufficient momentum to ensure sufficient mixing.The reasonable air-staging mode has less effect on the combustion of the boiler and the boiler thermal efficiency loss is less than 0.5%.As a result,the goal of reducing the initial NO_xemission of the pulverized boiler can be achieved by using the reasonable air-staging method,under the condition that the efficiency of the boiler is not affected.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1313K]

  • Experimental study on removal of mercury emission from the flue-gases by using moved bed adsorption apparatus

    BAI Jingli;HAO Yanhong;WANG Jiawei;GAO Yangyan;Department of Environmental Engineering,Shanxi University;

    In order to find the optimum technology conditions for mercury adsorption removal in flue gases of thermal power plant,the experimental study of mercury removal was conducted on an industrial prospective switchable moved-bed apparatus with two adsorbents. A simulated flue gas was provided according to the mercury concentration and temperature in actual power plant,and two kinds of adsorbents were made by adding bentonite into fly ash in certain proportion.The physical and chemical properties of the samples were studied by combined multi-functional X ray diffraction meter,energy dispersive X ray fluorescence spectrometer,automatic surface area meter and scanning electron microscope.The results showed that the main mercury removal process was physical adsorption at 60-100 ℃,the mercury removal efficiency decreased when the adsorption temperature and adsorption time increased,and the mercury removal efficiency of adsorbent A was significantly higher than that of adsorbent B,because A has higher carbon content and better pore structure.On the whole,the mercury removal efficiency using moved-bed adsorption apparatus is higher than that of fixed-bed.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 3419K]

  • Optimization of ultra-low emission capacity distribution in CFB boiler internal and external desulfurization system

    ZHANG Lei;WANG Shaochen;YUAN Guangcun;LI Shuyuan;Shenhua Guoneng Shandong Construction Group Co.,Ltd.;

    After the ultra-low emission reforming,the CFB boiler adopts two stage desulphurization method.For this kind of desulphurization,there is a best internal and external desulphurization capacity distribution plan,which makes the whole unit have the highest comprehensive economic efficiency under the premise of emission compliance.In order to study the best distribution scheme of desulphurization capacity,the optimization model was established through theoretical analysis.By using this optimal model and collecting a large amount of operational data,the internal and external desulfurization ratio under different boundary conditions was calculated to guide the operation.The results show that according to the optimal desulphurization ratio,the example plant A annually saves 1.08 million yuan,which is equivalent to reducing coal consumption by 2.66 g/k Wh; and power plant B annually saves 1.4 million yuan,which is equivalent to reducing coal consumption by 1.52 g/k Wh.Theoretically,it is an effective means of energy saving and emission reduction.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1518K]

  • Methods to treat waste water from limestone wet flue gas desulfurization in power plant

    GUO Zhiwen;LIU Junjun;GAO Zhijia;LI Shuhua;JIA Yonghui;Jingneng(Xilin Guole) Power Co.,Ltd.;

    In order to meet the emission standard of wastewater from limestone wet flue gas desulfurization in power plant,the process of wastewater treatment technology of neutralization-sedimentation-flocculation-clarification which was used as a global prevailing technology was described.Based on the characteristics of desulphurization wastewater from electric power plant of Jingneng( Xilin Guole) Power Co.Ltd.,the new process characteristics of wet flue gas desulfurization were introduced in detail.It is a new type wastewater treatment process in which the p H value of the wastewater is firstly adjusted by limestone slurry( Ca( OH)2),and then only high-efficiency flocculant( GX) is added.The wastewater can meet the discharge standard after high-speed stirring,flocculation and sedimentation.The results show that when 11% high efficiency flocculant( GX) is added into the wastewater,the treatment effect is better. It is determined by orthogonal experiment that when the p H is 5.0 after adjusting,the dosage of high efficiency flocculant( GX) is 11% and stirred at a high speed of 200 r/min,Then after standing for 10 min,it has a good purification effect,and the heavy metal content in the wastewater is also lower than the discharge standard of DL/T 997—2006.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1501K]

  • Technology of steam heating method to removal gas fog

    ZHANG Pan;FAN Xiangzi;Hangzhou Research Institute of China Coal Technology & Engineering Group;

    The phenomenon of white mist occurs at the outlet of the chimney for limestone-gypsum wet desulfurization not only influences the visual effect,but also affects the diffusion effect of contaminants.Smokes emitted from the wet desulfurization unit were with strong corrosive,high moisture contents and low temperature properties that is easy causing the corrosion on steam-smoke heat exchanger quickly and increase the volume and high steam consumption.In this paper,a number of measures for the removal of white mist were compared,and researches were carried out on steam heating technology in service aspects of corrosion resistance of materials,types of heat exchangers and selection of steam for heat exchanging and validated in engineering application.SAF2205 high frequency welded pipe is used as a tube for steam-smoke heat exchanger proposed herein,H-shaped finned heat exchanger tubes commonly used in the coal saver for boilers are applied in steam heat exchanger for the elimination of white mist,and medium temperature.Low pressure saturated steam is used to offer heat sources to increase heat exchanger efficiency and reduce steam consumption which achieves better effects in engineering application. The temperature of heated smokes reaches 82 ℃,so that white mist from the chimney is removed effectively.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1483K]

  • Influence of the separated fly ash on the performance of geopolymer foam material

    WANG Xia;JOW Jinder;JI Hongwei;DONG Yang;LI Qiao;WANG Ke;National Institute of Clean-and-Low Carbon Energy,Beijing;

    In order to study the influence of classified fly ashes and their mixtures on the properties of geopolymer foam materials,the raw ash and its graded ash with different particle size and compounds were compared under the same preparation process and formulation,and the amount of foaming agent was adjusted accordingly.By controlling the dosage of the foaming agent and the mix ratio of classified fly ashes,the geopolymer foam materials at different dry densities were prepared.The results show that the 28-days compressive strength values of the geopolymer foam materials at different dry densities prepared by using 100% original fly ash were lower than the standard values due to its wide particle size distribution.The classified fly ashes,FA-2( average particle size finer than the original fly ash) and FA-1( average particle size close to the original fly ash) utilized by NICE patented classification technology,can improve the compressive strength of their geopolymer foam materials.When the ratio of FA-2 to FA-1 is at least 1 ∶ 1,different dry densities foam materials can be prepared.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1688K]

  • Technology of the preparation of polyaluminium chloride from coal gangue

    WU Haibin;XUE Fangbin;GUO Yanxia;CHENG Fangqin;YANG Fengling;Shanxi Rui En Ze Technology Co.,Ltd.;State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources,Institute of Resources and Environmental Engineering,Shanxi University;

    The preparation of the polyaluminum chloride flocculant( PAC) from coal gangue is one of the important utilization ways of coal gangue.The effects of polymerization temperature,polymerization time,Al3+concentration and calcium aluminate powder dosage on the index of polyaluminum chloride products were investigated by single factor experimental.The results show that the optimal condition of polymerization are the ratio of the mass of coal gangue( g) to the volume of hydrochloric solution( ml) 1 ∶ 3.5 and the polymerization conditions 80 ℃,120 min,1.5 mol/L Al3+in the acid leaching solution,and 150 g/L calcium aluminate powder in the acid leaching solution.The as-prepared polyaluminium chloride contains 10.3% Al2 O3 with a basicity of 65.6%,which is in accordance with Class I of the HG/T 2677—2009.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 2031K]

  • Dual atmosphere thermogravimetric test method to measure carbon content of fly ash

    DUAN Xuelei;JOW Jinder;DONG Yang;FENG Bo;LI Qiao;National Institution of Low Carbon and Clean Energy,Beijing;

    In order to determine the carbon content of fly ash accurately,TG-MS was used to simulate and track the weight loss of combustion process under the traditional method of loss on ignition( LOI)( GB/T 176—2008) and dual atmosphere thermogravimetric method( first inert atmosphere and then oxidizing atmosphere).The results show that the weight loss of fly ash measured by the traditional method is mainly composed of water evaporation,decomposition of inorganic compounds and combustion of unburned carbon. The carbon content tested by the LOI method is overestimated.The dual atmosphere thermogravimetric method can distinguish the source of weight loss.The loss of weight under inert atmosphere is the volatilization of water and the decomposition of inorganic compounds,while the weight loss under oxidizing atmosphere is the true content of unburned carbon.Water and inorganic compounds content,carbon content and weight loss on ignition are available in one experiment.It is worth to popularize the test method of dual atmosphere thermogravimetric for carbon content of fly ash,which is more accurate and convenient.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 1855K]

  • Improvement of air pressure system of plate and frame diaphragm filter press

    ZHOU Airong;WANG Gang;Daichiba Coal Preparation Plant,Sichuan Guang Wang Group Company;

    Aiming at the problems of moisture instability of filter cake,high exhaust noise and failure of valve seals in the process of " screw compressor and plate and frame diaphragm filter press" in Daichiba coal preparation plant,the air press system and hydraulic press system were compared.The air press system was improved and the effect was analyzed.The results show that compared with compressed air press,hydraulic press has the advantages of low moisture content,low energy consumption,no noise pollution,high force density,good stability,effective equipment protection,high safety and easy maintenance,but it also exists the disadvantages of poor reactivity,high performance requirement of press pump,and large floor area,and so on.By transforming air pressure membrane filter plate,hydraulic press supporting facilities and hydraulic press control safety mechanism,the coal preparation plant can save 505,900 yuan per year.

    2018 04 v.24;No.116 [Abstract][OnlineView][HTML全文][Download 3062K]
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