Fluidized bed boilers for washery rejects -- Operating experience and prospects in India

The power sector in India is faced with the dilemma of satisfying increasing demand for electric energy and the need to generate it as cost efficiently as possible with minimum detrimental impact on the environment. It is therefore essential to evolve strategies for enhancing the power supply not only through new projects but also through better utilization of existing sources. Deterioration in coal quality as adversely affected performance of power plants based on PF boilers necessitating beneficiation of non-coking coal involving two product separation in to prepared coal and reject. Operational results of pilot plant and commercial plants based on fluidized bed combustion technology have shown the advantages of this technology and its effectiveness in burning low-calorific value fuels in an environmentally friendly manner. The process of FBC combustion has been demonstrated practically for all the types of coals available in India and provides the answer for power generation from high ash coal and reject from beneficiation plants and thereby ensures conservation of coal resources dwindling at an alarming rate. This paper describes four industrial FBC projects based on washery rejects and coal/lignite. The unique feature of Indian installations is the design basis for burning washery rejects up to 70%more » ash and HHV of 1,600 Kcal/kg plants have been discussed. Potential of power generation from washery rejects and quantum of coal conserved by installing this capacity has also been worked out in this paper.« less