Exergetic and environmental performance improvement in cement production process by driving force distribution

Abstract

This paper presents an investigation of the effects of temperature gradient distribution by the aid of a secondary burner on exergetic and environmental functions of the cement production process. For this reason, the burning system of the cement production (kiln & preheater) process was simulated in four thermal areas. Three lines of cement production with 2,000, 2,300 and 2,600 ton/day were investigated. Fuel injection ratio into the secondary burner, from 10 to 40 percent was studied for each line. The obtained results show that, for cyclone preheaters, fuel injection into the secondary burner up to a proportion resulting in the minimum temperature required for alite formation (2,200 °C) in the kiln burning zone is suitable. For shaft preheaters, however, according to percent calcinations, there exists an optimum proportion for 15 to 20 percent injection fuel into secondary burner. Finally, it was shown that the secondary burner application can reduce the exergy losses about 25 percent, which leads to a reduction of the green house gases of about 35000 cubic meters per year for each ton per day of clinker production.