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1 shbaeck@inha.ac.kr Coal ( 석탄에너지 ) 백성현 Office : 2 남 308, x7474

2 BET (Brunauer, Emmett & Teller) Equation 가스나액체를구체표면에등온흡착시켜분말고체의표면적을측정하는방법 v P = 1 + c 1 P ( P0 P) vmc vmc P0 P 0 : 포화증기압 c : 상수 ( 첫단일층의흡착에너지상수 ) v : 주어진증기압에서흡착된증기의부피 Vm : 단위중량의고체에서단층으로흡착된증기의부피

3 Y v P = 1 + c 1 P ( P0 P) vmc vmc P0 X P v(p - 0 P) (C-1)/VmC 1/VmC P P0 P/P 0 = 0.05~0.35

일반적 S( m / g) 3 Vm( cm / g, STP) 23 = 6.

4 일반적 S( m / g) 3 Vm( cm / g, STP) 23 = ( mol 3 22,400( cm / mol) 2 1 ) σ

5 Example Calculation of Surface Area from BET Equation P/P 0 Adsorbed N 2 (cc/g) P/P 0 (X) P/V(1-P/P 0 ) (Y) Y = X 1/VmC = (C-1)/VmC = C = Vm = 3.92 cc/g S = (3.92 / 22400) x 6.02 x x x = 17.1 m 2 /g

Berylium, Thalium, Chromium, Cobalt, and Zinc. Other: Chlorine, Fluorine, PAHs, Sulfur, Dioxins.

6 Coal Composition Coal is not pure carbon, even Anthracite has impurities. Trace metals: Lead, Cadmium, Manganese, Arsenic, Antimony, Copper, Mercury, Barium, Nickel, Selenium, Berylium, Thalium, Chromium, Cobalt, and Zinc. Other: Chlorine, Fluorine, PAHs, Sulfur, Dioxins. Mercury (Hg) Lead (Pb) Polycyclic aromatic hydrocarbons Coal Cleaning Removal of sulfur from coal. Scrubbers are used to trap SO 2 when coal is burned

7 Coal is of great interest because it is: Plentiful. Resource ~ 500 years (vs. gas/oil: ~100 years). Inexpensive $/GJ HHV (vs. gas at 2.5+ $/GJ). Ubiquitous. Wide geographic distribution (vs. middle east). Clean?! Gasification, esp. with sequestration, produces little gaseous emissions and a chemically stable, vitreous ash. Disadvantages Expensive pollution controls Acid rain Global warming

8 CO 2 Emission

9 Coal Sources Coal is the world s most plentiful fossil fuel. Recoverable world coal reserves are estimated at about 1X10 12 tons. 7% 5% United States 7% 8% 12% 32% Russia China Australia Germany South Africa Poland 29%

10 Coal Composition Proximate Analysis Elemental Composition C H O S N Char Ash H 2 O VM 65-95% 2-7% <25% <10% 1-2% 20-70% 5-15% 2-20% 20-45% From CHNOS Analysis

11 Coal Combustion 1st step : Combustion of Volatile Matter 2nd Step : Combustion of Char Carbon Reaction C + ½ O 2 CO CO + ½ O 2 CO 2 CO 2 + C 2CO C + O 2 => CO 2 Non-Carbon Reaction S + O 2 SO 2 H 2 + ½ O 2 H 2 O H 2 O + C CO + H 2 CO + H 2 O => CO 2 + H 2

12 Main Processes in Coal Combustion Volatiles homogeneous combustion CO 2, H 2 O, oal Particle Devolatilization char heterogeneous combustion CO 2, H 2 O, t devolatile =1-5ms t volatiles =50-100ms t char =1-2sec t

13 Coal Combustion: Air Pollutants CO 2 CO NOx SOx Particulate matter Trace metals Organic compounds Coal combustion emissions in Israel: 71% of total SO 2 emissions. 62% of total CO 2 emissions. 39% of total NOx emissions. 38% of total SPM emissions. 1% of total CO emissions. Six Pollutants : CO, Pb, NO 2, O 3, SO 2, PM (Particulate Matter)

14 Carbon Dioxide, CO 2 C + O 2 CO 2 Almost 99% of C in coal is converted to CO 2. CO 2 sequestration is being tested. Carbon monoxide, CO C + ½O 2 CO air/fuel ratio residence time temperature turbulence

15 Hemoglobin ( 헤모글로빈 ) 적혈구속에존재하는색소단백질 철함유 (4 Fe / Hemoglobin) 산소운반 (1.36mL O 2 / g Hemoglobin)

16 Coal-S radicals (CS, S 2, S, SH) SOx O 2, M -SO 4 SO SO 2 SO 3 char SO 2 molecule COS, CS 2 H 2 S Sources of sulfur in coal: Seawater sulfates, Limestone

17 Sulfur in Coal (<10%) Organic sulfur (40%) Chemically bonded to the hydrocarbon matrix : thiophene, thiopyrone, sulfides and thiol. Inorganic sulfur (60%) Imbedded in the coal, as loose pyrite - FeS 2 or marcasite, and calcium/iron/barium sulfates. H 2 S : H-S-H Mercaptan : H-S-R

18 Nitrogen Oxides (NOx) Thermal NOx, Prompt NOx, Fuel NOx Thermal NOx N 2 + O NO + N N + O 2 NO + O Zeldovich mechanism Strong temperature-dependence: > C Not a major source of NO in coal utility boilers. Thermal NOx 생성조건 (1) 연소온도가높을때 (2) 연소영역에서산소농도가높을때 (3) 고온영역에서연소가스의체류시간이길때

19 Prompt NO (Hydrocarbon + N 2 ) N 2 + CH x HCN + N + N + OH NO + H Prevalent only in fuel-rich systems. Not a major source of NO in coal utility boilers. Fuel NO (Char-N, Volatile-N) 1. Char-N Char-N + ½O 2 NO 2. Volatile-N Volatile-N HCN/NH 3 HCN/NH 3 + O 2 NO The major source of NO in coal utility boilers (>80%).

20 [Char-NO = ~25%] < [volatiles-no = ~75%] Name Structure ~ Relative amount Stability Pyridine 1 N 15-40% More stable Pyrrole 1 N H 60% Less stable Aromatic amines NH % Stable

21 SCR (Selective Catalytic Reduction) * 선택적촉매환원법 (SCR) NOx 와 NH 3 를촉매에접촉시켜 NOx 를 N 2 와 H 2 O 로생성하는방법 주반응 4NO + 4NH 3 + O 2 4N 2 + 6H 2 O 2NO 2 + 4NH 3 + O 2 3N 2 + 6H 2 O 경제성, NOx 제거효율, 공정특성등비교시가장우수한공정 * SCR 촉매 금속산화물 (Fe 2 O 3, Pt, CuO, WO 3 ) 부터 zeolite 에이르기까지다양 바나듐계 (V 2 O 5 ) 촉매가우수한것으로알려짐 자세한촉매의특성은알려지지않음 전체운전비의약 70% 차지

22 NOx control options (from AP-42, EPA) Control Technique NO Reduction Potential(%) Overfire air (OFA) Low NOx Burners (LNB) LNB + OFA Reburn SNCR SCR LNB with SCR LNB with OFA and SCR 85-95

23 Particulate Matter Bottom Ash, Fly Ash Electrostatic precipitator (ESP) 99% (for 0.1>d(μm)>10) <99% (for 0.1<d (μm)<10) Fabric filter (or baghouse) As high as 99.9% Wet scrubber 95-99% Cyclone 90-95% (d(μm)>10)

24 1) Bag House 3) Cyclone 2) Electrostatic Precipitator 효율이좋다. 운영비, 설치비가비싸다. 5 μm 이상의입자제거 가장일반적으로쓰임

25 Organic Compounds Volatile Organic Compound(VOC) Semivolatile Organic Compound Condensable Organic Compounds Polynuclear Aromatic Hydrocarbon (PAH) Napthalene Benzopyrene

26 Coal Gasification Reaction ΔH (kcal/mol) Coal H 2 CmHn, C C + H 2 O CO + H 2 C + 2H 2 O CO 2 + 2H 2 C + CO 2 2CO C + 2H 2 CH 4 CO + H 2 O CO 2 + H 2 CO + 3H 2 CH 4 + H 2 O C + O 2 CO Combustion 2C + O 2 2CO Combustion Coal Pyrolysis Steam Reforming Steam Reforming Boudouard Reaction Methanization Water-Gas Shift Reaction

27 Thermodynamic Equilibrium

28 Energy Step 1: Treat heated, crushed coal with superheated steam: < 3000 kcal/nm 3 C + H 2 O CO + H 2 Step 2: CO reacts with H 2 to produce met hane and water: CO + 3H 2 CH 4 + H 2 O Or reacts with water: 5000 ~ 6000 kcal/nm 3 CO + H 2 O CO 2 + H 2 Step 3: Purification & Removal of CO ~ kcal/nm 3

29 Coal Oxygen or Steam Gasification Power Generation Gas Cleaning CO + H 2 Chemical Synthesis CO Conversion H 2 Ammonia Synthesis Ammonia City gas Fuel cell Industrial fuel Household fuel For coal liquefaction Transpotation fuel High Energy Density Low Pollution

30 Integrated Coal Gasification Cycle : IGCC 국내의화력발전환경규제치강화추세 Year SO x (ppm) NO x (ppm) Particulates(mg/m 3 ) 년이후신규발전소 NOx 80 ppm 으로규제 가스화 는근본적으로 연소 에기초한기존화력발전과는화학반응자체가틀림. 산소가부족한환원분위기반응 : No SOx / NOx 석탄내황성분 : H 2 S 로발생, 황산 / 유황으로회수, 판매가능 석탄내질소성분 : NH 3 로발생, 세정편이 석탄내회분 : 중금속침출문제없는 slag 으로발생, 도로포장재등으로재활용

31 CO 2 emissions (kg/kwh) IGCC SOx : 25 ppm 이하 NOx : 60 ppm 이하 CO 2 : 15 ~ 30% 감소 PM : 5 mg/m 3 이하 Coal Crude oil Natural gas Pulverized coal combustion PFBC IGCC Combined Cycle MCFC 0.1 Combined Cycle MCFC Power generation efficiency(%),

32 IGCC (Integrated Coal Gasification Combined Cycle) Chemical conversion of coal to synthetic gas for combustion in a modified gas turbine 30% increase in efficiency over brown coal steam power plant Corresponding 30% reduction in CO 2 emiss ions Power costs 30% less than conventional st eam plant Suitable for high moisture fuels including b iomass Cf) ICFC (Integrated Coal Gasification Fuel Cell Combined Cycle)

35 Comparative SO 2 Emissions Emissions in Pounds per MWH New Coal Current IGCC New Natural gas

36 Comparative NOx Emissions Emissions in Pounds per MWH New Coal Current IGCC 0.07 New Natural gas

37 Carbon Capture and Sequestration Sequestration of Carbon in the Oceans Enhancement of the Natural Terrestrial Cycles Sequestration of Carbon in Underground Geologic Repositories Management of Carbon by Sequencing Micro-organisms

38 Cost of Electricity in $/MWh Without CCS With CCS Conventional Coal IGCC Conventional Coal IGCC Bituminous Subbituminous Clean Coal Technique Coal Gasification ICGC, ICFC Coal Liquefaction

39 Coal To Liquid 석탄 산소수증기 가스화기 가스정제 (CO+H2) F-T 합성 석탄간접액화 생성물분리 / 정제 디젤휘발유 촉매 수소 액화반응기 upgrading refining 수소공여용매 석탄직접액화

40 Coal Liquefaction Direct Method 1) Direct Method (Hydrogenation) Indirect Method

목차 ⅰ ⅲ ⅳ Abstract v Ⅰ Ⅱ Ⅲ i

11-1480523-000748-01 배경지역 ( 백령도 ) 에서의 대기오염물질특성연구 (Ⅲ) 기후대기연구부대기환경연구과,,,,,,, Ⅲ 2010 목차 ⅰ ⅲ ⅳ Abstract v Ⅰ Ⅱ Ⅲ i 목차 Ⅳ ii 목차 iii 목차 iv 목차 μg m3 μg m3 v 목차 vi Ⅰ. 서론 Ⅰ μm μg m3 1 Ⅰ. 서론 μg m3 μg m3 μg m3 μm 2