Design and Techno-economic analysis of power generating unit from waste heat (Preheater and grate cooler) of cement factory in Ethiopia

Abstract

Abstract Waste heat from industries, when are not captured, is useless and contributes to environmental pollution. There are many methods to recover the waste heat generated from local industries, but this present work was done on shell and tube type heat exchanger for waste heat recovery. Recapturing and reusing this waste heat by using waste heat recovery would simultaneously reduce energy prices and greenhouse gas emissions. This present work aims to design and techno-economic analysis of power generating unit from waste heat (preheater and grate cooler) of cement factory line 2 to avoid the problems that are caused due to the burning of fossil fuels and to ensure the environmental sustainability. This present work is design and techno-economic analysis of power generating unit consist of mixing chamber, electrostatic precipitator, shell and tube type heat exchanger, superheater, piping systems, steam turbine, surface condenser and feedwater pump as its main components. Several methods were used, including secondary data collection, system design, and system cost analysis. The factory s collected data was the temperature of waste heat from the grate cooler stack of 285℃ with the amount of 1.938\xa0kg/kg of clinker and which leave the six cyclone preheater tower stack of 323℃ with the amount of 2.69\xa0kg/kg of clinker. Three scenarios are intended to make use of waste heat. According to calculation results, the power was produced from each scenario, and due to those power techno-economic analyses of the power generating unit was performed. Because of its high steam upgrade, high production of power, high-cost savings, low payback period, low condenser load and high pumping power, scenario one was selected than scenario two and three.