The cement industry is one of the most energy intensive manufacturing sector in which energy represents 25 to 40% of the total production costs. In order to identify energy efficiency improvement and GHG reduction measures for cement factories in Ethiopia, energy audit was conducted in National Cement Factory. From the energy balance, the main cause of thermal energy loss in the kiln were the exhaust gas, the hot air from the cooler and the kiln surface, which accounted 21.53%, 10.8%, and 4.27% of input fuel energy to the kiln, respectively. The main causes for the loss of electrical energy were low power of electric motors and motors operation under load which caused the motors not to operate at their maximum efficiency. To enhance the performance of the system, the feasibility of identified energy conservation measures such as replacement of Seal, improving kiln Re-fractories, Reduction of kiln shell heat loss, waste heat recovery for power generation and operating motors with above 75% load that have low or reasonable pay-back period.
Dr. Demiss Alemu obtained his B.Sc. in Mechanical Engineering in 1979 from Addis Ababa University, his M.Sc. from Politecnico di Torino in Italy in Automotive Engineering in 1985 and Dr.-Ing from Technical University of Aachen in Germany in 1993 in Thermal Technology. He was the Department Head of Mechanical Engineering and Associate Dean for Graduate Studies and Research of Faculty of Technology. Currently, he is serving as an Associate Professor of Thermal Engineering at Addis Ababa Institute of Technology, AAU.
He has served as Board Chairman and Technical Advisor for some factories in the manufacturing sector. He has also conducted feasibility studies for integrated steel mill, integrated pulp and paper mill, PVC raw materials and chemical plants, energy efficiency improvement studies and trainings in different manufacturing sectors. He has published nearly about 20 articles.