Industrial Waste as Alternative Fuel in Cement Industry: Its Impact on Environment

Cement manufacturing is a high energy consuming and highly polluting process. Cement producers are trying to reduce the energy and environmental costs by using alternative fuels and raw materials through their research and development. Alkaline environment, high temperature and long processing time allow cement kiln to burn a wide range of waste and hazardous materials. This paper summarizes and reviews literature on the usage of different types of industrial wastes as alternative fuel. It also discusses their advantages, disadvantages, selection criteria and impacts on environment. It is concluded from the literature review that none of the individual alternative fuels can claim as the best alternative fuel on the basis of their energy value, level of greenhouse gas emissions and operational merits and demerits. Rather, it is suggested that the maximum benefit can be achieved by using a blend of different alternative fuels together with fossil fuel with appropriate percentage of substitution, which needs to be quantified. Further research study is being carried out at the Central Queensland University (CQU) to determine the optimum blending ratios to achieve higher thermal efficiency.