Energy consumption assessment in a cement production plant

Energy consumption assessment in a cement production plant is studied in this paper and a guideline for reducing energy consumption is provided according to a national standard-ISIRI 7873. Based on energy assessment, several energy saving actions were implemented and valuated. The proposed energy saving actions varied between simple actions to complicated and high-cost investments. By introducing energy saving actions, the electrical and thermal energy required for each additional unit of production decreased by 10.4% and 7.6% from 2008 to 2010, respectively. Hence, considering improvements introduced to the process control, this led to 22.6% and 19.9% improvements in the electrical and thermal specific energy consumptions, respectively. The Cumulative SUM of differences technique (CUSUM) was applied to assess saving actions in the period of implementation. The benefit of the CUSUM is that it gives a method to measure whether steady saving conditions are achieved or not. The continual improvement achieved since the slopes of trend lines in the CUSUM charts decreased for both electrical and thermal energy in 2010 in comparison with 2009. Also, the total cost savings in 2009 and 2010 were about 3.4 million USD which covered all of the 2.5 million USD costs of the implemented actions.