Alternative fuels from waste products in cement industry

Abstract

Although fossil fuels such as coal, petroleum, and natural gas can provide all the energy the world needs for the time being, the fast depletion in their current world reserves, their bad effect on the environment and global warming, and their possible utilization as raw materials in more added-value industries suggest that other alternative fuels should be considered in energy-intensive industries. Today's cement industry becomes more challenging for the following main factors: the lowest production cost and the lean environmental impact. One of the most effective methods for accepting the challenge is to use the alternative sustainable fuels. The required specific calorific values can be achieved by mixing of high calorific primary fuel with low calorific alternative fuel. The substitution rate depends on the type of alternative fuel used and plant design and operation parameters. A substitution rate of up to 80% can be achieved on a permanent basis. One hundred percent substitution was recorded in a plant-utilizing liquid waste in its main burner. The main alternative fuels used in cement industry are residue oil and solvents, contaminated wood and process waste from wood, used tires and rubber waste, plastic waste, thermal fraction of domestic waste, sewage sludge, and animal meal.