Analysis of COAL for UTILIZATION P M V Subbarao Professor Mechanical Engineering Department Knowledge to be Quasi-static while Destroying the Permanent Entropy Vehicles…..
Combustion performance Thermal Performance Slagging. Fouling &Erosion Operational Issues Fuel Handling system Fuel Preparation Combustion System Thermal structures Design Issues Fuel & Air
Analysis of Coal Proximate Analysis & Ultimate Analysis. Proximate analysis - to determine the moisture, ash, volatiles matter and fixed carbon Ultimate or elementary analysis - to determine the elemental composition of the coal
Fuel Model
Dictionary of Few Indian Coals
Ash Model
Additional Characteristics of Coal Sulfur Content : Coal with sulfur > 5% is not recommended for combustion. Weatherability : Weathering or Slacking Index. An indication of size stability Denotes the tendency to break on exposure to alternate wet and dry periods. Weathering index is the percentage of of coal passing through a seive having 170 mm2 openings.
Additional Characteristics of Coal Grindability Index : A measure of relative ease of grinding coals or the power required for grinding coals in a pulverizer. GI = 6.93 W + 13 -- W is the weight of sample passing through 200 mesh size. Important in milling of the coal to a P.F. size specification. Burning Characteristics of Coal : Free burning coals and Caking Coals -- Caking index -- Pulverulent, sintered, weakly caked, caked and strongly caked. Ash Fusion temperature -- The temperature where the ash becomes very plastic -- Design of ash handling system. -- Stoker furnace cannot use low ash fusion temperature coals.
Maximum Extra-somatic Energy Content of A Fuel Obtained only thru Combustion. Standard heat of combustion: The energy liberated when a substance X undergoes complete combustion, with excess oxygen at standard conditions (25°C and 1 bar). The heat of combustion is utilised to quantify the performance of a fuel in combustion systems such as furnaces, Combustion engines and power plants. In industrial terminology it is identified as the Gross Heating (calorific) Value or Higher Heating (calorific) value. In a general design calculations, only Net Heating (calorific) Value or Lower Heating (calorific) value is used.
Ranking of Coal Medium Volatile Bituminous Sub Bituminous (C ) High-Volatile (C ) Bituminous LowVolatile (C ) Bituminous Anthracite B A B A HV High Rank Low Rank
Analysis of Coal The Energy content -- CFRI Formulae -- Low Moisture Coal(M < 2% ) -- CV (Kcal/kg) = 71.7 FC + 75.6 (VM-0.1 A) - 60 M High Moisture Coal(M > 2%) -- CV(kcal.kg) = 85.6 {100 - (1.1A+M)} - 60 M Where, M, A, FC and VM denote moister, ash , fixed carbon and Volatile mater (all in percent), respectively.
Measurement of Calorific Value : Bomb Calorimeter : Control Mass
Thermodynamic Description of Bomb Calorimeter It is a combination of two closed systems. Bomb: Constant volume closed system: Interacts only with calorimeter. Calorimeter: Outer constant volume closed system: Interacts only with bomb. Isolates entire system with ambience.
The Bomb & Fuel
Temperature of Water in the Jacket
Energy Balance & Estimation of CV Who all accepted the Thermal energy (heat) liberated due to combustion?
Biochar Production Process
Biochar Production at IIT Delhi Kiln Capacity:25 L, Efficiency:20-25% Feedstock: Leaf Waste, Operating Temperature<450° C
Analysis of Biochar Biochar samples C (%) H N S O O/C H/C Moisture Volatile matter (%) Fixed C (%) Ash pH LWB400 79.4 2.3 0.2 8.6 0.11 0.03 1.2 64.9 24.7 9.3 10.2 LWB300 71.3 3.1 0.9 0.5 12.6 0.18 0.04 1.6 67.5 20.3 10.6 9.8 LWB200 68.3 4.8 1.1 14.2 0.21 0.05 2.2 71.0 15.8 11.0 9.6