COAL WATER SLURRY FUEL Alternate Fuel for Thailand

Transcription

1 COAL WATER SLURRY FUEL Alternate Fuel for Thailand Power-Gen Asia 2014 Royal Daniel Managing Director

2 Contents Introduction of POWER Burns and Roe Coal Water Slurry (WS) Fuel in General Method of Retrofitting a Steam Boiler Operation of CWS Power Plant and its Performance Air Emissions and Thailand Standards Conclusion 2

3 Power Engineers/Burns and Roe TWO FIRMS. ONE POWERHOUSE. One of the World s Leading Engineering and Consulting Companies designer of electrical distribution and power generating facilities in the U.S. 220 Generating Units, totaling 120,000 MW Over 20,000 MW of capacity engineered within the last five years. Strong experience in fossil, nuclear and renewable generation Ranked as a Top ENR Engineering Firm 80 years of engineering many of the world s largest, innovative and most challenging projects Full Service Regional Engineering Service in Thailand 90 Staff 75 % of Business From Repeat Clients 3

4 Who We Are» POWER Engineers Began in 1976 as two-person firm Employs ~ 1,800 people 100% employee-owned Strong corporate culture attracts quality long-term employees Multidiscipline power delivery and generation experts Largest, dedicated power delivery staff of any North American consultant Strong experience in renewables: wind, solar (PV & thermal), hydro, geothermal Small to mid-sized SC and CC gas turbine experience Responsive and flexible to clients needs» Burns and Roe Incorporated in 1932 Employs ~ 500 people Privately Held and Family Managed Leading designer of power generation and electrical distribution facilities in the U.S.: ~220 Generating Units, totaling 120,000 MW Strong experience in the fossil, nuclear and renewable generation Broad range of coal, cogeneration, combined cycle, and recip engine experience Over 80 years of engineering many of the world s largest, innovative and most challenging projects 4

5 Full Range of Services to the Electric Industry Owner s Engineering Independent Engineering Due Diligence Project Permitting Engineering and Environmental Studies Project Siting and ROW Selection Detailed Engineering Design EPC Engineering Partner for Generation EPC Prime for Substation Projects Electrical Testing and Commissioning 5

6 Generation Project Markets Gas Turbines Reciprocating Engines Solar Wind Geothermal Hydro Nuclear Energy Coal-Fired Waste-to-Energy 6

7 COAL WATER SLURRY (CWS) FUEL Alternative Fuel in Thailand 300 MW oil-fired Krabie Power Plant located in Krabie, Thailand owned by Electric Generation Authority of Thailand ( EGAT ). Uneconomical to operate on HFO. Standby unit. Plan is to improve economic to mid-merit dispatch and add coal to the fuel mix. 7

8 1. COAL WATER SLURRY (CWS) FUEL IN General Rationale of development clean coal technology include: Abundance and relative low cost per BTU for coal. Reduce dependence on consumption of Natural Gas and the much higher priced Oil. Add coal to the generation fuel mix in an economic and environmental friendly manner. Potential lower life cycle cost by retrofitting uneconomical heavy-fuel oil boilers than to build new coal plant. Diversity of fuel can improve fuel availability and pricing security. Fuel options for generation are limited and tendency of the commercial fuel close to depletion. 8

9 COAL WATER SLURRY ( CWS ) FUEL An alternative fuel for HFO thermal power plant Chinese Technology developed and/or refined by Zhejiang University Plants range in size from 2 to 210 MW 9

10 World Wide Experience EGAT studying application to 300 MW HFO Krabie Power Station, Thailand 10

11 The Development of CWS Fuel Production Process Feed stock Technology Off taker To produce CWS fuel, there are three blocks in the process: 1. Feed stock: Acquiring, transporting, storing the subbituminous coal. 2. Technology: Washing, Crushing, Wet Milling to produce CWS. 3. Off- taker: Storage and transportation of the CWS. 11

12 Coal Feedstock Specification Coal Specification for the imported coal to Thailand 1. Total Moisture 20 % 2. Ash Content Air Dry Basis ( ADB ) 10 % 3. Volatile Matter (ADB) 40 % 4. Fixed Carbon (ADB) 42 % 5. Total Sulfur (ADB) 0.7 % 6. Gross Calorific Value (HHV) 5,500 Kcal/kg 7. Hardgrove Grindability Index >38 8. Grain size < 50 Micron 12

13 CWS Technology Application Motor Operated Wet Roller Mill Plant Chinese technology: 1. Wet roller mill plant: to grind the coal with water and additive at proportion of 70:29:1 2. The average gain size is around 10 to 20 micron. 3. Tanks farm for CWS storage and supply to Customers. 13

14 The physical property of CWS fuel CWS Fuel Specification 14

15 Clean Coal Technology 1. A Heavy Fuel Oil (HFO) fuel substitute produced by mixing coal with water and an additive which changes the coal state from a solid to viscous liquid. 2. The properties are: Low ash Low sulfur Low combustion temperature Low particulate and dust Physical properties are similar to HFO. Transported as liquid 15

16 2. Process of Retrofitting CWS Steam Boiler 1. Survey and Study of the Existing Power Plant 2. Perform Feasibility Study of Retrofitting Power Plant 3. Detailed Design of Retrofitting Power Plant 4. Procurement of the Equipment 5. Implementation of the Retrofitting Power Plant 6. Test and Commissioning of the Retrofitting power plant 7. Performance and Air Emission Test The typical expected project duration is months for Retrofitting. 16

17 Retrofitting to a CWS Steam Boiler Burner modification Boiler Modification Atomize fuel and flame length modification Boiler heat surface and heat transfer check and calculation Induce Draft ( ID ) fan and Forced Draft ( FD ) fan modification Boiler Control System Modification Emission Control System Modification Boiler Operation and Reliability Ash and sediments modification Five key engineering items which are required to be modified or improved on the existing heavy oil boiler power plant to allow for using the CWS fuel. 17

18 Steady Ignition and Efficient Combustion Special new burners for CWS to ensure efficient economic consumption of the CWS (more viscous and higher flow rate than HFO). CWS will have longer length of the burner flames causing higher temperatures. Need to control the possible higher exit temperature of the flue gas, the potential higher upper furnace and super heater temperatures within the boiler, and to make sure that the flame stability allows for flexibility for load variations of the boiler. Atomizing system to be suitable to the CWS high viscosity and higher flow rate. Efficient and complete atomization of the CWS is possible with steam. 18

19 Ash and Sediments Issue is management of boiler fouling from coal ash. To prevent the furnace fouling from the accumulation of slag and sediments, a removal system for the bottom ash is required. Another problem of ash during burning the CWS fuel is the speed of flue gas within the boiler which may cause of abrasive wear of the outer external walls of the boiler tubes. In order to prevent the tube corrosion and abrasive tube wear trouble, ash content in the CSW needs to minimize. Tube shields can also be considered at areas of expected high abrasive wear. 19

20 Heat Transfer and Heating Surface Heavy oil fired boiler are designed for higher total heat input while maintaining lower upper furnace and super heater temperatures than that achievable with CWS due to the shorter flame length with oil than the CWS. The operating challenge of CWS is to keep the steam output as high as possible while keeping the required super-heater and re-heater temperature limits. The cooling devices used in CWS fired boiler will need to be adequate for controlling the operating temperature, and also keeping the surface temperature of air pre heater. 20

21 Boiler Control System Modification (Sufficient Airflow) Confirm existing capacity of Forced Draft Fans and Induced Draft Fans can meet the higher requirements of retrofitting boiler with CWS. The fans will need some adjustment of to increase the air flow produced. The control system of retrofitted CWS boilers needs to be modified for the stability of operation. 21

22 Boiler Operation Modifications for Reliability The installation of additional equipment for washing the CWS fuel pipeline to keep them free of CWS blocking. Improve new technology of quick ignition and modified switching system. Modification of the internals of pumps, valves, pipelines, heating surface, and nozzles to protect from abrasion of sediments. Modify the control system of CWS boiler for part load operations. 22

23 3. Operation of CWS Retrofitting Power Plant Operation side Power output of the existing power plant de-rated by 30% Environmental friendly Emission can be controlled Economic dispatch merit order improved Reliability factor is 85% Economical side Lower Retrofitting cost than building new plant. Expected range of capital cost to retrofit is 30 to 50% of new build. Price of fuel is lower than HFO. Life extension to 15 years after power plant Retrofit. 23

24 The Comparison of Different Type of Fuels Case study of 300 MW Oil-fired Krabi power plant (EGAT) to CWS Retrofitting power plant. Description Unit COAL CWS HFO Power plant capacity MW 210 Annual electric generation GWH 1490 Gross Heat rate BTU/kwh Gross calorific value BTU/kg Daily Fuel consumption Tons/day Fuel cost in ton USD/ton Fuel cost in MMBTU USD/MMBTU Fuel rate Kg/kwh Annual fuel consumption Millions ton The comparison of different type of fuel of 210 MW Krabi power plant 24

25 Benefits and Performance of Retrofit Power Plant The benefit after retrofit Time duration for retrofitting is shorter and lower investment cost than new build. Reliability of operation is the same as oil fired boiler. Test result of performance and reliability after retrofit Fuel efficiency is about same as oil fired. Output will be de-rated by 30%. Reliability factor of 85%+ for the power plan. 25

26 220 TPH Shantou Oil-Fired Boiler Retrofit to 100% CWS Thermal Performance 26

27 Operation of CWS Plant and its Performance The environmental friendly power plant which built to mitigate the air emission to lower level about 50 ppm of particulate matter. 27

28 670 tph (200 MW) Nanhia CWS Thermal Plant Performance 28

29 4. Air Emission and Thailand Regulation In Thailand, using normal coal is very sensitive issue with opposition from NGO and Ecologist. In case of clean coal, we can apply high technology for controlling the air emission to atmosphere and operate within the regulation of Thailand as shown in table below: Country Particulate matter (mg/nm3) SO2 (ppm) NOx (ppm) Standard Thailand TISI Standard China GB Latest version 29

30 Forecasted Air Emissions and Standard Regulation Low air emission due to lower operating firing temperature than oil and pulverized coal combustion boilers. Attributes of a CWS installation: CWS is prepared from washed fine coal fuel with low ash and sulfur content(<7%) and low sulfur(<0.5%). The flame temperature in CWS combustion is lower by 100 to 150 than that of pulverized coal combustion. Therefore the pollutants such as fly ash, SO2 and NOx are relative lower than pulverized coal. 30

31 Suitable for Tight Plant Sites CWS is especially suitable for plant which lacks of the space to install coal mills and coal storage silos and coal storage yard. No requirement to handle solid coal at the plant site with associated noise and dust issues. CWS can be produced in a remote location and be transported to the power plant site as a liquid. The level of back-end mitigation of emission will be lower for CWS reducing the requirement for addition back-end emission control by additional equipment such as Selective Catalytic Reduction ( SCR ) for NOx control, Flue Gas Desulfurization ( FGD ) for SO2 control, and Electrostatic Precipitator ( EPS ) for particulate matters emission control. If emission equipment is still required for CWS, the efficiency of the equipment required will likely be lower reducing the cost. 31

32 Retrofitted CWS Steam Boiler with Emission Control System CWS power plant with the pollution control for NOx, Sox, and Particulates 32

33 5. Conclusion CWS is a challenging fuel for retrofitting of existing heavy oil fired boilers. Proven to be technically and economical viable option. CWS may be better than others liquid fuel because of it is lower cost than heavy fuel oil. CWS also brings coal into the generation mix coal fired generation with a lower air emission profile than pulverize coal fired power plants. CWS can be viewed as a bridging clean coal technology for retrofitting existing heavy oil fired boilers to allow for more coal in the electric power generation fuel mix at a faster pace. Integrated Gasification Combined Cycle ( IGCC ) power plant could be the next phase of generation of power plant taking advantage of the coal resources. CWS also provides an opportunity for uneconomical heavy fuel oil fired power plants to produce electricity at more competitive energy price allowing them to be a larger contributor to the electric generation mix. 33

34 Thank you Terima Kasih Royal Daniel Managing Director Kasem Naknual Consulting Engineer/BD Burns and Roe Asia Ltd., Thailand 34