Performance evaluation of a plaster production plant using energy exergy and exergoeconomics analyses

In this thesis, thermodynamic analysis of endustrial furnaces, in which heat treatments have been done, in stalled in a plaster production factory and CFD analysis of a rotary kiln were made. Energy, exergy and exergoeconomic analysis methods were applied to the perlite furnaces and rotary kiln processes. In addition to these analyses, CDF analyses of the rotary kiln were performed. Energy and exergy efficiencies of the former perlite expansion furnace were determined to be 66 % and 26 %, respectively. The energy and exergy efficiency values for the new perlite expanssion furnace were calculated to be 69 % and 37 %, respectively. The energy and exergy efficiencies of the rotary kiln were obtained as 69 % and 16 %, respectively. The cost per unit of exergy of the natural gas was 13.601 US$/GJ for the former perlite expannsion furnace (FPEF) and 12.345 US$/GJ for the new perlite expansion furnace (NPEF). The fuel exergy costs entering the FPEF and NPEF were 57.287 US$/h and 53.651 US$/h. The production costs based on exergy and the exergoeconomic factor of the FPEF are calculated to be 0.153 US$/kg and 45 % while those of the NPEF were obtained to be 0.100 US$/kg and 70 %, respectively. The cost per unit of exergy of the natural gas consumed in the rotary kiln was 13.7606 US$/GJ. The fuel exergy cost entering the rotary kiln was 218.1457 US$/h. The CFD analysis shows that the maximum temperature was 1868.64 K in the current working conditions. Based on the second CFD analysis, that maximum temperature was 2437.77 K in the second situation which created being cut with flue gas recirculation and removal of part which was the gypsum entry into the furnace. Second working conditions were better than those of current working conditions of the rotary kiln according to the gas velocity distribution in the furnace. Energy and exergy analyses of the former, the new perlite expansion furnaces and the rotary kiln have shown that high amounts of energy efficiency could be obtained from these furnaces. The findings obtained from the exergy analysis were supported by the findings of exergoeconomic analysis. It was concluded that the rotary kiln was operated under inefficiencies conditions based on its CFD analysis results.