Modelling for integrated energy optimisation in cement production plants

Abstract

Cement production is an energy intensive process. In South Africa the cost of energy increased since 2006, while cement sales have dropped dramatically. It has become important to focus on methods to optimise energy consumption to achieve cost savings in the cement industry. Various methods of reducing production cost by improving energy efficiency are available, but require extended installation periods and high initial capital expenditure. Other methods such as operational optimisation can reduce production cost, but offer limited savings. The aim of this study is to integrate the optimisation of multiple component operations to improve savings and reduce interruption during implementation. Although integrated optimisation models have been developed, no literature could be found on the application of these models in the cement industry. This thesis reports on the development and implementation of an energy management system at four South African cement plants. The total electricity costs were reduced without installing costly infrastructure upgrades. The results summarise the success of the improved production planning. A conclusion regarding the feasibility of this implementation is compiled by comparing the savings achieved by the implementation of the energy management system to other energy saving methods. Recommendations are also made for further study and the implementation of the energy management system in similar industries.