A Conceptual Approach to Hybridize Pulverized Coal Fired Boiler with Fluidized Bed Boiler for Cleaner Power Generation

Abstract

Power conversion through conventional fossil fired technology produces different pollutants in spite of use of efficient technologies like supercritical, ultra-supercritical, IGCC, FBC etc. Also, technology like, CCS, scrubber, SCR and ESP are used to capture of CO_2, SOx, NOx and SPM respectively but at the cost of overall plant efficiency. Co-firing technology is another approach to mitigate pollutants. Despite the use of these methods for arresting the pollutants, complete removal is practically not possible and limited stock of fossil fuel compelled engineers, scientists and technologists to concentrate more on pollution free and sustainable renewable energy sources. But present renewable energy source cannot fulfill our total energy demand due to their low generating capability, high power cost and mostly are intermittent in nature. At this juncture hybridization of fossil fuel technology with renewable sources may be one of the alternatives technologies till complete switchover from conventional power conversion method to renewable power generation, which required further technological advancement and innovation. A new hybrid boiler is conceptualized which capable of burning large verities of fuel ranging from wood to pulverized coal and also its own mill rejects from pulverize section. CO₂ generation can be reduced upto 50% per unit of power generation compare to solely fossil firing unit. NOx generation can be reduced by reducing furnace temperature through flue gas mixing, SOx can be captured by feeding CaO in fluidized section and SPM can be arrested by ESP successfully. New hybrid boiler requires techno-economical evaluation to realize in practical use with Palash Wood as main biomass fuel supported by pulverized semi-bituminous coal.