Slagging behaviour of coal combustion

Abstract

newlineIn India majority of the coal resources are found to be inferior grade due to the high ash newlinecontent in them. But, the demand for the power generation and fuel utilization in India is newlineincreasing at rapid rate. Still, India depends upon the coal based thermal power plants for newlinethe majority (gt75%) of electricity generation. To compensate the demand Indian power newlinesectors and other coal derivative sectors are trying to utilize the low rank Indian coals. newlineCoal pyrolysis has been crowned as the twenty first century clean coal technology in newlineconversion of organic matter into high energy products such as syngas and oil along with newlinechar as the byproduct. Present work is divided into two parts, in first part the slagging newlineproblems related to the utilization of high ash Indian coals in thermal power plants has newlinebeen analyzed and the remedies to the slagging problems were discussed. In second part, newlinethe coal pyrolysis of high ash Indian coal was investigated using TGA analysis. The newlineeffect of ash on the pyrolysis of coal has been studied. newlineThe FactSage thermodynamic software was used to identify the phase transitions newlineand slagging behavior of Indian low rank coal in boiler operation conditions. The newlineexperimental AFT results of coal ash were correlated with the thermodynamic results. newlineThe viscosity of the slag formed was calculated using the Urbain model of viscosity newlineequation. Conventional AFT analysis doesn t give any information about the newlinecompositions in the slag and crystalline phases. Urbain model viscosity calculations newlineassumed that all the ash component is in slag-liquid state, is doesn t consider the newlinecrystalline phase during the calculations. In some operating experiences low percentage newlineof slag phase is detected even though furnaces are operated at high temperatures newlinecompared to the flow temperature analysis from AFT analysis. So, it is necessary newlineconsider the crystal phase for effective calculation of fusion temperature and viscosity. In newlineFactSage viscosity calculations, both slag-liquid and crystalline phases are considere