CLEAN COAL TECHNOLOGIES FOR SUSTAINABLE POWER DEVELOPMENT Dr. V. K. SETHI Prof. & Head RGPV Bhopal

WORLD SUMMIT ON SUSTAINABLE DEVELOPMENT PRIORITIES ON ENERGY GENERATION SECTOR: Increased use of Advanced Fossil Fuel Technology. Promote CCT in countries where coal is main stay fuel for Power Generation. Reduce Atmospheric Pollution from Energy Generating Systems. Enhance productivity through Advanced Fossil Fuel Technology.

POWER SCENARIO IN INDIA Installed capacity in utilities (March 31, 2002)   Thermal 73,274 mw Hydro 25,574 mw Nuclear 2,860 mw Wind 1,427 mw Total 1,03,135 mw Total energy generation - 383 billion kwh Per Capita Energy Consumption -400 kwh

DEMAND PROJECTION YEAR 2012 CAPACITY ADDITION BY SECTORS Central 46,500 MW State & IPP 41,800 MW NCES 10,700 MW Nuclear 6,400 MW Total 105,400 MW YEAR 2020 MIX OF GENERATION Thermal 326,000MW Renewable & Hydro 104,000 MW Nuclear 20,000 MW Total 450,000 MW

CLEAN COAL TECHNOLOGIES Mining Management & Practices (Reduction of Extraneous material) Coal Preparation Process after mining to improve inherent & Extraneous material (washing & beneficiation) Conversion Technologies Supercritical, PFBC and IGCC Post combustion cleaning Particulate and gaseous pollutants removal (Environmental requirement)

CLEAN COAL TECHNOLOGIES VISION 2020 PROGRAM Gasification using + fluidized bed, moving bed or Entrained bed Gasifiers In-combustion Clean-up Fluidized bed combustion (CFBC, PFBC, AFBC) Post combustion Clean-up-Desulfurization (FGC systems) Supercritical Pre combustion Clean-up beneficiation/washing CLEAN COAL TECHNOLOGIES Technologies for utilization of Coal for Power Generation with minimal pollutants discharged to the atmosphere (Reduced CO2, Sox, Nox, SPM) at high conversion efficiency……….World Coal Institute.

CLEAN COAL TECHNOLOGIES Clean Coal Technologies (CCTs) are defined as ‘technologies designed to enhance: Efficiency of conversion Environmental acceptability of coal extraction, preparation and use.

COAL FOR POWER GENERATION China and India are projected to account for30% of the world’s increase in energy consumption between 2000-2020 and 92% of increase in coal use. The key environmental challenges facing the coal industry are related to : Coal Mining Particulate emission Disturbance land me Acid rain Ozone and Waste disposal

INDIA AMONGST TOP SIX EMITTERS OF CO2 Country Total emission Percentage of (Million Tonnes of CO2) world emission USA 5470 24% China 3121 14% Russian Federation 1456 6% Japan 1173 5% Germany 884 4% India 881 4%

Note : Green House inventory for India for Energy Sector (Million Tonnes of CO2) Energy Sector CO2 CO2 equivalent (CO2+CH4+NOx) Total Emission 508 565 (58% of total) (64% of total) Source : IAE : 1999

PER CAPITA EMISSIONS OF CO2 Top 6 Polluters

COST OF VARIOUS CO2 MITIGATION OPTIONS FOR INDIAN POWER SECTOR

Zero Emission Technology (ZET) This technology combines and forms a part of : Clean Coal Technologies Solid to liquid fuel technology GHG mitigation technology Clean Development Mechanism for power sector Non-CFC Refrigerant and Non-CFC Aerosol Propellant Technology Clean Aviation Fuel or ATF for aircraft Substitute LPG for domestic use.

Measures to achieve Sustainable Development Promoting CCTs, including carbon sequestration is essential to a balanced cost effective climate change response Developing countries where coal combustion efficiencies are low CCT promotion a need of the day.

EFFICIENCY IMPROVEMENT FORECAST CONVENTIONAL Vs IGCC ( Courtesy BHEL) 60 55 50 45 40 35 30 1990 1995 2000 2005 2010 Year of commercial use Net Thermal Efficiency (%) Ceramic gas turbine 566 C o 600 C 623 C 1300 C 1500 C 540 C 650 C 1184 C IGCC (15 C Amb) IGCC (Indian Condition) Super Critical PC Power Plant (15 C Amb.) Super Critical PC Power Plant (Indian Condition) Sub Critical PC Power Plant (Indian Condition)

POLLUTANT GENERATION FROM PC PLANTS No Change Scenario Specific Coal Consumption =0.75 KG/KWH Coal Ash : 43% Sulphur : 0.6% Ideal Scenario =0.35 KG/KWH Ash : 15% Sulphur : 3% 1997 2002 1997 2002 1997 2002 1997 2002 1997 2002 1997 2002

RELATIVE EMMISSION PC PC+FGD PFBC IGCC

SUPER CRITICAL UNITS Standardized Unit Size 660 MW, 246 ata, 537 oC Station Size 2x660 MW (Minimum) Common Off site facility FW Temperature 270 oC – 275 oC with 6 Heaters. Total Capacity Planned 14,560 MW * Number of Units 22 Units * Includes 6x720 MW and 2x500 MW Imported sets.

Main advantages of Super-Critical Steam Cycle Reduced fuel cost due to improved thermal efficiency Reduction of CO2 emissions by 15% per unit of Power generated compared to sub-critical Very good part load efficiencies Plant costs are comparable with sub-critical units

Current State-of-Art Super-critical Steam Power Generation Plants Pressure - 300 bar Temperature - 600oC Efficiency - 45% (LHV Basis) Nickel based alloys allows up 650oC By the year 2005 - 620 oC By the year 2020 - 650-700 oC Cycle Efficiency - 50-55%

R&D IN SUPERCRITICAL TECHNOLOGY Main Thrust Areas : Materials & Metallurgy for components of boiler & turbine subjected to high temperature and high pressure. Supercritical cycle optimization -incremental heat rate improvement Retrofit of supercritical boiler to subcritical PC boiler Fluidized bed supercritical steam cycles Once through HRSGs with supercritical parameters Multi-reheat supercritical boilers with double/triple reheater.

SUPER CRITICAL SCENARIO EXPECTED BENEFITS: Coal Saving 1,565,200 Tonnes Co2 Emission Reduction 1,909,544 ” SO2 Emission Reduction 11,648 ” Ash Reduction 661,752 ”

COAL BASED COMBINED CYCLE PLANT Routes Combustion Gasification Hot Flue gas under pressure drives the G.T. Pressurized gasification process produces fuel for G.T. Pressurized Fluidized – BED Combustor (PFBC) Options Available Moving – BED Entrained – BED

COAL BASED COMBINED CYCLE POWER GENERATION Offers Plant efficiency over 44% with advanced GT Has Lower emission of gaseous and solid pollutants Accept Inferior and varying quality of coals Lower water requirement Capability of phased construction and retrofitting

IGCC TECHNOLOGY ... Gasification of coal is the cleanest way of utilization of coal, while combined cycle power generation gives the highest efficiency. Integration of these two technologies in IGCC power generation offers the benefits of very low emissions and efficiencies of the order of 44-48%. The comparative indices show that in case of IGCC, emission of particulate, NOx and SOx are: 7.1%, 20% and 16%, respectively, of the corresponding emissions from PC plant.

IGCC ... Environmental performance of IGCC plants far exceeds that of conventional and even supercritical plants. Three major areas of technology that will contribute to improvements in IGCC are : hot gas de-sulfurisation hot gas particulate removal advanced turbine systems

DEVELOPMENTAL GOALS FOR IGCC To utilize India’s low grade coal for power generation with improved plant efficiency. To introduce coal gas in Natural Gas based Combined Cycle Plants in a phased manner. To increase power generation capacity at the level of present emission. To develop state of Art Technology for Indigenous and Export Markets.

IGCC

IGCC DEVELOPMENT PROGRAM IN INDIA MAJOR MILE STONES: Choice of gasification for high ash coals by BHEL 6.2 MW IGCC demonstration plant established by BHEL both with Moving Bed and Fluidized Bed. Coal Characterization by BHEL & IICT for gasification application. Intensive data generated by IICT on oxygen-steam gasification in their Moving Bed gasifier. Task force CEA, CSIR, NTPC & BHEL constituted to assess technological maturity & Financial requirement for a green field IGCC plant of 100 MW capacity at Dadri (NTPC). BHEL, CSIR & NTPC prepared proposal for setting up of this 100 MW IGCC demonstration plant.

Circulating fluidized Bed Combustion Circulating Fluidized Bed Combustion (CFBC) technology has selectively been applied in India for firing high sulphur refinery residues, lignite, etc. CFBC Technology is superior to PC Power Plant Technology: Lower NOx formation and the ability to capture SO2 with limestone injection the furnace.

Circulating fluidized Bed Combustion Good combustion efficiencies comparable to PC Power Plants. The heat transfer coefficient of the CFB furnace is nearly double that of PC which makes the furnace compact. Fuel Flexibility: The CFB can handle a wide range of fuels such as inferior coal, washery rejects, lignite, anthracite, petroleum coke and agricultural waste with lower heating.

Circulating Fluidised Bed Boiler Steam to Super Heater Cyclone Furnace Coal Feed Hopper Ash Cooler Back-Pass ESP External Heat-Exchanger HP Air

CFBC Vs Other Clean Coal Technologies 0.8-0.98 1.49 1.0 Relative O&M Cost/kW 1.15-1.42 1.03-1.19 Relative Capital Cost/kW 41-42 36.7 34.8 Cycle Eff. % IGCC PF+FGD/SCR CFBC ITEM At present pulverized fuel firing with FGD are less costly than prevailing IGCC technology. However, firing in CFB Boiler is still more economical when using high sulfur lignite and low-grade coals and rejects.

Renovation & Modernization (R&M) and Life Extension (LE) of old power plants is a cost-effective option as compared to adding up green field plant capacities. Growing environmental regulations would force many utilities within the country to go for revamping these polluting old power plants using environmentally benign CFBC technology.

SUMMERY Sustainable Power Development calls for adoption of Clean Coal Technologies like Supercritical cycles, IGCC and FBC technologies Supercritical Power technologies may selectively be used for Pit Head power generation using washed coal

SUMMERY IGCC can revolutionize the power generation scenario in India, once the commercial viability of technology with high ash coals is established at the proposed 100 MW plant. The success of the project will largely depend on maturity of Fluidized bed gasification technology for high ash Indian Coals. CFBC technologies are particularly useful for Boiler Emission reduction through revamping of old polluting plants.

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