Coal Ash utilization in power plant-2.pptx

Ash utilization in power plant

1. NTPC SIPAT VOCATIONAL TRAING PROGRAM 2025 PROJECT ON “ASH UTILIZATION IN POWER PLANT” GROUP MEMBER :- INDRAJEET ( VT25MECH221 ) RIPANSHU ( VT25MECH 222 ) KESHAV CHANDRA SINGH ( VT25MECH223 ) SOHAM BHATTACHARJEE ( VT25MECH224 ) SACHIN KUMAR MISHRA ( VT25MECH225 ) KRISHNA KANT SAHU ( VT25MECH226 ) SAMEER ( VT25MECH227 ) AMAN SAHU ( VT25MECH228 )

2. CONTENT:-

3. INTRODUCTION Thermal power plants play a vital role in meeting global energy demands, particularly in countries like India and China, where coal is a dominant fuel. coal combustion produces a significant byproduct known as coal ash (or fly ash and bottom ash), which poses serious environmental and economic challenges if not handled effectively. This report explores the concept of ash utilization , aiming to convert waste into wealth by reusing ash in various sectors such as construction, agriculture, and infrastructure. Ash is the residue left after the combustion of coal in thermal power plants. With the growing dependence on coal for electricity, the generation of ash has increased, necessitating effective utilization strategies

4. GENERATION OF ASH IN POWER PLANTS Coal combustion in thermal power plants results in: • Fly Ash (FA): Fine particles carried by flue gases, captured by electrostatic precipitators (ESPs) or bag filters. • Bottom Ash (BA): Coarser ash that settles at the furnace bottom. • Pond Ash: Ash collected in ash ponds. • Conditioned Ash: Ash mixed with water or other materials for safe disposal or transportation. Depending on the coal quality and plant efficiency, the ash content can vary from 20% to 45% by weight of the coal consumed. India alone generates over 200 million tonnes of ash annually .

5. CLASSIFICATION OF ASH Ash is categorized based on its physical and chemical properties: Fly Ash Siliceous material with pozzolanic properties. Fineness < 45 microns. Used in cement, bricks, roads, embankments. Bottom Ash Granular and coarser. Used in concrete, road construction, and embankments. Pond Ash Mixture of fly ash and bottom ash. Lower pozzolanic activity. Requires treatment before reuse.

6. METHODS OF ASH COLLECTION AND HANDLING Dry Collection System Fly ash is collected directly from ESPs. Ensures better quality ash for use in cement and bricks. Wet Collection System Ash mixed with water and transported to ash ponds. Environmentally riskier due to water pollution and land usage. High Concentration Slurry Disposal (HCSD) Used to minimize water usage and leakage in ash transport.

7. ASH UTILIZATION TECHNIQUES Cement Industry Fly ash is a supplementary cementitious material. Reduces the need for clinker (high CO₂ emitter). Brick and Block Manufacturing Ash-based bricks are lightweight, eco-friendly, and cost-effective. Road Construction Used in sub-grade and embankment construction. Enhances soil stabilization

8. Land Reclamation Filling abandoned mines, low-lying areas. Needs proper lining to prevent leaching. Agriculture As a soil conditioner to improve pH, water retention. Rich in micronutrients like calcium and potassium. Lightweight Aggregates Used in concrete to reduce dead load. Ceramic and Tile Industry Ash can substitute clay or sand in tiles and ceramics.

9. ENVIRONMENTAL AND ECONOMICS BENEFITS Environmental Reduces land requirement for ash ponds. Lowers groundwater pollution. Minimizes greenhouse gas emissions by reducing clinker use. Economic Converts waste into a marketable commodity. Reduces disposal cost. Promotes circular economy in energy sector.

10. CHALLENGES IN ASH UTILIZATION

11. GOVERNMENT POLICIES AND GUIDELINES ( inDIA FOCUS )

12. ash generation and its effect Ash is an inherited impurity of coal that will not burn. Typical range is 5% to 40%. Reduces handling and burning capacity. Increases handling costs. Affects combustion efficiency and boiler efficiency. Causes clinkering and slagging . Ash is generated as the product of combustion of coal Comprices of 80% fly ash and 20% bottom ash Parameter Indian coal coal south African coal Ash content (%) 38.63% 13.99% 17%

13. Need for Ash Utilisation

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