Clean Coal Energy and Environment in China Prof. Kefa Cen Zhejiang University, China 2005.8.22
Low Per Capita Energy Reserves 能源人均储量偏低 2000 年人均能源储量 Per capita energy reserves in 2000 种类项 Item Category 石油 Petrol 天然气 Natural Gas 煤炭 Coal 人均可开采储量 Per capita minable reserves 2.6 t 1074 m 3 90 t 占世界平均值比例 Ratio to world average value 11.1% 4.3% 55.4%
Composition Ratio of Installed Capacity 2000 2005 2010 2015 总装机 Total GW 319 430 (446) 550-590 (666) 710-760 发电装机容量构成比例 水电 Hydro % 24.8 25.5 25.8 26.3 煤电 Coal % 69.3 66.6/ 63.6/ (72.7) 60.8 油电 Oil % 4.8 3.5 2.5 2.0 气电 Gas % 0.3 1.9 5.4 6.9 核电 Nuclear % 0.7 2.0 2.3 3.1 新能源 Renewable % 0.1 0.5 0.7 0.9 2020 2020 900-950 1006GW 27.1 246GW 24.45% 58.6 623GW 61.9% 1.6 7.5 60GW 5.96% 4.2 36GW 3.58% 1.0 41GW 3.98% Coal power needs 400 X 900 MW Super critical units which consume coal---2 billion ton. 燃煤发电净增 400 X 900 MW 超临界机组需消耗 20 亿吨煤
Gas emission of total world quantity resulted from coal combustion in Energy consumption SO2 NOx CO CO2 China percent of total world quantitative 8~9 % 15.1 % 10.1 % 9. 6 % 13.5 % Percentage by coal (%) 87 % 67 % 71 %
Flue gas clean technology Other Pollute Contral technologies FGD & DeNOx Flur gas dust precipitation Institute for Thermal Power Engineering Clean Coal Technology Advanced power Generation Coal conversion Coal processing IGCC PFBC-CC CFB Supercritical PF technologies Coal liquefaction Coal gasification Coal water slurry Briquette Coal washing
The State of Art of Clean Coal technology and The Developing Trends R & D, Application and Development of Clean Coal Technology Coal washing and processing a) Coal Washing The Combustion, Gasification and Power Generation Technology of washing tailing sludge 煤泥燃烧 气化及发电技术 b) Coal water slurry
Coal washing sludge Combustion in CFB 洗煤泥流化床结团燃烧原理 Characteristics of coal washing sludge: 1.Particle size<0.5mm,ash>40%,moisture>25% 2.Non-Newton Newton fluid, heating value:1000-3000kcal/kg
Key Techniques and innovations 采用大粒度高位给料, 以利于燃料形成较大凝聚团 Large particles feeding at the top of furnace 使煤水混合物在流化床内结团燃烧, 在较高断面热负荷下实现较高燃烧效率 Conglomerate sludge fired in CFB 采用异重流化床技术, 以防止凝聚团在流化床内沉积, 保证稳定运行 Novel technique with different-density bed materials in CFB
Conglomerate sludge fired in CFB 煤泥凝聚团 -- 异重流化床燃烧基础
20900 Now 25 power stations has been built 4500 0.0 75t/h Slime Fired Boiler Structure in Dongdan Power Plant 东滩 75t/h 洗煤泥循环流化床锅炉简图
Replace oil by Coal Water Slurry 水煤浆代油燃烧技术 Dependence on the imported oil of China in 2000-2020 2000 年 2010 年 2020 年 dependence on import(%) 31.0 institute of energy of state planning 45~52 59~62 commission IEA 61 77 IEA 54 72
中国石油的供需问题 Supply and demand of oil in china Price of imported oil in 2000 Price of imported oil in 2005 180$/ton; 476$/ton (65$/barrel) Year 2005:25.2 billion $; 66.6 billion $. Year 2010:46.9 billion $; 123 billion $. Year 2015:81 billion $ ; 214 billion $. Year 2020:131.5 billion $; 345 billion $.
Replacement of oil by CWS Standard quality of CWS: concentration:65~70%; viscosity:~1000cp; grain size:d<50μm ash content:a<7%; sulfur content:s<0.5%
水煤浆雾炬燃烧机理 Combustion mechanisms of CWS
3.52 MW pilotscale test facility in Zhejiang Univerisity
670t/h (200MW) CWS fired boiler at Nanhai power plant, Guangdong,China
汕头电厂 220t/h 水煤浆锅炉燃烧效率 Combustion efficiency of a 200t/h CWS fired boiler at Shantou power plant, Guangdong,China run Load % carbon in fly ash% Carbon in bottom ash % Thermal efficiency% Combustion efficiency % 1 40 3.27 2.4 91.23 99.60 2 50 2.15 2.4 91.11 99.74 3 60 2.052 2.15 91.88 99.73 4 80 3.65 1.92 92.03 99.58
Pollution emission from a 220t/h CWS fired boiler at Maoming power plant term unit 22nd, Jun time 23rd, Jun 24th, Jun Average state standard load t/h 185 180 177 180.6 / SO 2 NO x Particle mg/nm 3 mg/nm 3 mg/nm 3 634.3 351.7 30.67 585.1 359.4 25.64 585.1 359.4 25.64 541.4 362.4 20.26 2100 650 200 ZJU s CWS combustion technology have been applied to over 70 boilers.
The State of Art of Clean Coal technology and The Developing Trends Clean Coal Power Generation Technology b) CFBC d) IGCC Combined clean coal utilization technologies
循环流化床锅炉 Circulated fluidized bed Combustor
CFB 降低 SO X 排放 SOx emission reduced by CFB Pulverized Coal W/O Scrubber * World Bank Standard * US Clean Air Act Amendment 1995 Limit European Community Standard * US Clean Air Act SOURCE: The World Bank Amendment 2000 Limit Environment Guidelines Typical CFB (95% Removal) * 0 1000 2000 3000 4000 5000 6000 * Assumption 4wt% Sulfur Content HHV=14MJ/kg mg/mj
CFB 降低 NO X 排放 NOx emission reduced by CFB European Communlty Standard Pulverized Coal World Bank Standard CFB without Nox Control CFB with Nox Control SOURCE: The World Bank Environment Guidelines 0 100 200 300 400 500 mg/mj
R & D, Application and Development of Clean Coal Technology Clean Coal Power Generation Technology b) CFBC International: 250MWe CFBC- commercial operation 400Mwe CFBC- design China: Over 1000 6MWe-125MWe CFBC- Operation Imported 300MWe CFBC-demonstration
R & D, Application and Development of Clean Coal Technology Clean Coal Power Generation Technology d) IGCC International: 250MWe coal fired IGCC power plant put into operation China: IGCC system and key technology research 300~400MWe IGCC demonstration project
发展多联产技术 Multi-product cogeneration technology 化工产品 Chemical products 固体燃料 Solid fuel 气化炉 Gasifier 合成气 (CO+H 2 ) Synthetic gases 液体燃料 Liquid fuel 供热 Heat supply 发电 Power generation
煤的清洁 综合利用的预期结果 Prediction of Coal Clean Utilization CWS Coal washing (22.5%) Coal DeSOx 40-50% Gasification ( 裂解气化 ) heat & refrigeration Semi coke Power generation ash Coal sludge & Coal rejects Power generation coal gas electricity generation Extract vanadium Sewage & mud co-fired Municipal wastes &coal co-fired Biomass & coal co-fired Cement Construction materials
煤的清洁 综合利用的预期结果 Prediction of Coal Clean Utilization 80kg limestone ( 石灰石 ) 1ton coal ( 煤 ) Gasification ( 气化 ) 300Nm3 Fuel gas( 煤气 ) 80kg Tar( 焦油 ) Residue Char( 半焦 ) Combustion ( 燃烧 ) Ash utilization ( 灰处理 ) 235kg cement( 水泥 ) 1500kWh Electric( 电力 ) 6500MW Heat( 供热 ) 1600MW Refrigeration ( 制冷 )
1MW 循环流化床燃烧气化多联产试验平台 CFB boiler and gasifier based on Gas and Steam Cogeneration
给砂 给煤 点火油枪 M M 鼓风机 P 燃烧炉( 去固定床 ) P M P P M M P P M P 气化炉P P M M 给砂 给煤 放空 煤气引射器 M 放空 过热器烟气冷却器 1 M P P P O 2 P 冷却器 1 水大水槽冰M 洗涤塔 1 冷却器 2 洗涤塔 2 P P P 循环水泵 P 布袋除尘 + 引风 排气 分离器 过滤器 P 煤气泵 工业水气储罐紧急 煤P 煤气燃烧器 M 阻火器 试验装置系统流程图 Experiment diagram
浙大研制扬中 75T/H 多联产循环流化床锅炉 Yangzhong multi-generation CFB boiler
煤综合利用多联产系统 Multi-generation coal utilization system cement multi-generation stone coal utilization system
以煤油 电为主的多联产模式 multi-product cogeneration for coal oil and electricity Coal gasification Synthetic gas Gas turbine electricity power Flue gas Membrane separation Fuel cell Oil processing oil Synthetic oil Chemical Processing chemical
Near Zero Emissions Coal Utilization
Near zero emissions coal utilization technology with combined gasification and combustion Dust removal H2 H2 User Coal Biomass Steam H2 Pressure CFB Gasifier Char ash CaCO3 CaO ash Ash drain Dust Removal CO Pressure or atmosphere CFB combustor O 2 2 power Limestone H 2 O H 2 SOFC Gas turbine Air Gas turbine Water Air Heater HRSG Air Exit Air separation Condensation CO disposal 2 Steam turbine Air
CFB Gasifier CO 2 acceptor gasification process (~25bar) Main reactions in gasifier: C+H 2 O=CO+H 2-131.6kJ/mol CH 4 +H2O=CO+3H 2-206.3kJ/mol CO+H 2 O=CO 2 +H 2 +41.5kJ/mol CaO+CO 2 =CaCO 3 +178.1kJ/mol H 2 S+CaO=CaS+H 2 O Coal Biomass H 2 Pressure CFB Gasifier Char ash CaCO3 CaO ash CO2 Pressure or atmosphere CFB combustor Limestone Steam Ash drain O 2
CFB Combustor Char combustion CaCO 3 calcination Hydrogen combustion Main reactions in CFB combustor: H2 from SOFC CaCO 3 =CaO+CO 2-178.1kJ/mol H2 CO2 C+O 2 =CO 2 +393.791kJ/mol Coal Biomass Pressure CFB Gasifier Char ash CaCO3 Pressure or atmosphere CFB combustor Limestone H 2 +1/2O 2 =H 2 O+286kj/mol Steam CaO ash Ash drain O 2
Efficiency calculation for a sample Power generation:400mw Coal gasification ratio: 0.7 Operation Pressure: 25bar Temperature in the gasifier(k) 1205 Hydrogen production rate(kmol/s) 1.42 System efficiency(%)66.52 Proximate analysis/w%, ar Ultimate analysis/w%, ar Heat value/mj/k M V A C H O N S g, Q dw ar 2.7 25. 17 21.62 63.3 9 3.88 6.51 0.7 8 1. 13 23.143
Thermal Efficiency(%) HHV 60 50 40 30 20 10 Rankine Barrier First Station Efficiency Improvement Supercritical Boiler Pulverized Coal USC IGCC With Time FutureGEN3 FutureGEN2 FutureGEN1 PFBC IGMCFC TC IGHTA 0 1880 1900 1920 1940 1960 1990 2000 2020 AGMCFC HUSC Legend: PFBC -Pressured fluidized-bed combustion IGCC -Integrated gasification-combined cycle IGHTA-Integrated gasification-humid-air turbine IGMCFC -Integrated gasification-molten carbonate fuel cell AGMCFC -Advanced gasification-molten carbonate fuel cell USC -Ultra super critical TC -Topping cycle Years
Control of Pollutant Emission 污染物排放控制
Mercury Emission and Control during Coal Combustion Mercury transportation during coal combustion Element Mercury Oxidized Mercury Gaseous Mercury Particulate Mercury
Mercury Control Approach Gaseous Mercury Particulate Mercury Oxidized Mercury Element Mercury Captured in wet FGD scrubbers adsorbed onto porous solids Subsequent collection in a PM control device
Mercury Control Technology in Zhejiang University Hg 0 (g),hg2+ (g),hg (s) Coal Air Mercury Transportation Hg 2+ (g) Additives Spray Hg 0 (g),hg2+ (g) Hg (s) Separator Hg (s) Hg CEM Absorbents Control system
Hg removal research in a full-scale semi-dry reactor system separator Hg sampling fan diesel oil Hg sampling exhaust fan oil burner mixbox fan flowmeter fan Hg tube Hg compressor water N2
Hg removal in flue gas before fabric filter with different absorbents C/Hg 10 3
Fluorine ( F ) emission and control during coal combustion Fluorides are one of the most hazardous in atmosphere. Its toxicity is 10~100 times higher than sulfur dioxide and nitrogen oxide. 1ppb~5ppb of fluorine in the atmosphere is probably harmful to some impressionable plants.
Fluorine in Coal Fluorine concentration values for coals analyzed from China (dry basis) Coal rank Bituminous coal Anthracite Range (ppm) 17~696 61~1800 Average value (ppm) 173 308 Number of sample 81 28 Lignite 151~615 241 7 Stone coal 193~3313 1058 31 Gangue 259~1956 794 33
Fluorine Emission during Coal Fluorine release rapidly with increase of temperature The transfer ratio of fluorine is: about 95% for PC boiler about 80 ~ 85% for gratechain boiler about 70~80% for FBC Combustion F Tranfer ratio (%) 90 70 50 30 10 500 600 700 800 900 Temperature T(C)
Relationship between fluorine emission standard of industrial boiler and fluorine concentration in coal First class Second class Third class old boiler 9 mg/nm 3 15 mg/nm 3 50 mg/nm 3 corresponding fluorine in coal Ratio over standard 超标煤样数量比例 Bituminous coal anthracite lignite meager coal 101~112 ppm 42% 40% 90% 45% 169~187 ppm 19% 30% 31% 14% 407~452 ppm 4% 15% 7% 4% Attention: Fluorine transfer ratio is assumed at 80%
Fluorine Retention Compositions of sorbents sorbent CaO SiO 2 Al 2 O 3 Fe 2 O 3 MgO TiO 2 SO 3 K 2 O Na 2 O 石灰矿渣 limekiln residue 53.98 1.62 0.2 0.2 0.29 0.00 电石渣 carbide slag 60.98 5.42 3.00 0.19 0.00 0.08 0.28 0.07 0.05 钢渣 steel residue 30.35 18.5 3.42 22.8 16.35 0.039 造纸厂白泥 white mud 49.44 5.98 0.37 0.06 0.03 0.00 0.07 0.16 1.90
Efficiency of fluorine retention (%) 100 80 60 40 20 1# sorbent 2# sorbent 0 950 1000 1050 1100 1150 1200 Fuel-bed temp. ( æ) Effect of temperature on fluorine retention
Dioxins emission and control during MSW and coal co-fired process
Open burning
大气 沉积 再飞散 灰渣 空气中传播 废气 人类食物链 焚烧 工业过程 直接排放 浸蚀排放
二噁英 (Dioxin) - 所谓二噁英是对多氯二苯并二噁英 ( polychlorinated dibenzo-p-dioxin, 简称 PCDD) 和多氯二苯并呋喃 (polychlorinated dibenzofuran, 简称 PCDF) 的俗称 -PCDDs 和 PCDFs 分别由 75 个和 135 个同族体构成 8 9 O 1 2 8 9 1 2 7 6 O 4 3 7 6 O 4 3 PCDD PCDF
Dioxins emission data from different zones in the world (g I-TEQ/y) Zone 1987 1995 年 2000 年 2005 年 European Total emission 3685~6469 2434~4659 1960~3833 MSW incineration 1102~1434 538~706 294~419 Percentage% 22%~29% 15%~22% 10%~15% Power plant boiler 151~530 141~442 132~404 Percentage% 4.1%~8.2% 5.8%~9.5% 6.7%~10.9% U.S.A Total emission 12331 2888 MSW incineration 7915 1100 Percentage% 64% 38% Power plant boiler 51.4 60.9 Percentage% 0.4% 2.1% Taiwan Total emission MSW incineration Percentage% Power plant boiler Percentage% 67.25 3.745 5.6% 3.365 5.0%
Pilot Scale Multi-Function MSW Incineration Furnace 10t/d 10 吨 / 天多功能垃圾焚烧中试试验台
Dioxin Lab in ITPE of ZJU 二恶英专业实验室
高分辨率色谱质谱联用仪 (HRGC/HRMS)
800 吨 / 日大规模清洁焚烧垃圾电厂全景 The overall look of the 800 t/d MSW incineration plant
Dioxin Emission from Qiaosi MSW Incineration Plant in Hangzhou 杭州乔司垃圾焚烧厂的二噁英排放测试结果 设备 2004-1-12 1# 焚烧炉 Boiler 1 3# 焚烧炉 Boiler 2 负荷 Load 燃料比例 ( 垃圾 : 煤 ) fuel (MSW: coal) 测试日期 date 烟气含氧量 % (oxygen) 烟气 ( 比利时 SGS 实验测试结果 I- TEQ ng/nm3)flue gas 烟气 ( 省环境监测中心测试结果 I- TEQ ng/nm3 )flue gas 废气控制标准 standard I-TEQ ng/nm3 100% 84:16 2003-12-24 10.1~12.4 0.0068 0.034 1 106% 78:22 2003-12-23 5.6~11.1 0.0025, 0.0082 0.009, 0.077
Dioxins emission from Power Plant Boilers in China We suppose assumption 0.1 ng I-TEQ/Nm 3 ( 0.5 ng I-TEQ/kg coal ) EU regulation 1 ng I-TEQ/Nm 3 ( 5 ng I-TEQ/kg coal ) National regulation In 2020, total consumption of standard coal will reach 3 billion tons. 300MW Boiler stack gas emission 0.01352 ng I-TEQ/kg coal = 40.56 g I-TEQ/y = 1500 g I-TEQ/y EU regulation 15000 g I-TEQ/y National regulation Equals 4.6 billion tons MSW incineration annual at 0.1 ng I-TEQ/Nm 3 emission regulation
Removal of Multi-pollutants From Flue Gas by Ozone
The Removal Mechanism of Several SO Pollutants From Flue Gas + O 2 SO 3 SO2 + OH HSO 3 SO HO SO + OH 2 + 2 3 HSO + HSO3 + OH H 2SO SO 3 + O2 SO3 HO2 3 + H 2O H 2SO4 4 O + NO NO 2 NO + O + 3 NO2 O2 NO HO NO + OH + 2 2 NO + OH+ N + 2 HNO2 N2 NO + 2 + OH + N2 HNO3 N2 Hg + O HgO Hg + O3 HgO + O Hg + NO3 HgO + NO2 2 Hg + H O HgO + H O 2 2 2 Can be high efficiency removed by wet scrubber
Lifetime of the free radical is usually very short Lifetime of O 3 At the [O 3 ]/[O 3 ] 0 1.0 0.8 0.6 0.4 0.2 0.0 0 2 4 6 8 10 time s 150 200 250 150, the decomposit ion of O 3 is about 28% at 10s. The decomposit ion rate is keeping increased when temperatur e moved up.
Reaction time needed by O3/NO reaction T=150 At this temperature 0.1s is necessary for the conversion of NO. SO, the O3 s lifetime is enough for the reaction.
NO oxidization rate % 100 80 60 40 20 0 T=100 ; NO removal by O 3 Resident time is 0.09s; NO,NO 2,N 2 O was measured by Rosemount NGA2000 continue 0.0 0.2 0.4 0.6 0.8 1.0 1.2 O3/NO stoichiometric ratio NO oxidized rate NO oxidized by O3 at 100 emission monitor systems (CEMS) at 5s/scan. More than 80% NO can be oxidized
O3 and CO CO 浓度 [ppm] 500 400 300 200 100 0 空白 O3/CO=0.86 100 O3/CO=3.5 100 CO O3/CO=3.5 300 It found that CO doesn t react with O3 below 300
O3 with NO, SO2 reactions concentration [ppm] 200 150 100 50 100 NO SO2 SO2 doesn t have good performance like NO. How to improve the SO2 oxidization should be further studied. 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 O3/NO molar ratio
Power consumption by O 3 at 300MW Power generated Flue gas NO removed O3 needed O3 generated power power plant By O 3 MW 300 Nm 3 1.35Million ppm 100 Kg/h 289.3 kw/kgo 3 6 By Electro Beam 300 1.35Million 100 O2 generated power Kw/m 3 O 2 0.38 Average power consumption W/Nm 3 1.91 6.33 Total energy kw 2581 21375 % 0.86 7.13
Thank you