The kalina cycle for cement kiln waste heat recovery power plants

Abstract

Cement production is one of the most energy intensive industrial processes in the world. In many world regions, energy cost is 50% to 60% of the direct production cost of cement. Energy cost is incurred due to the need for large quantities of thermal heat for the kiln, calcination and drying processes and electrical energy for operation of motors for grinding mills, fans, conveyers and other motor driven process equipment. The Kalina Cycle/spl reg/ utilizes the waste heat from the cement production process to generate electrical energy with no additional fuel consumption, and reduces the cost of electric energy for cement production. The thermal efficiency improvement of the Kalina Cycle is 20% to 40% in comparison with conventional waste heat power plants that utilize the hot gases available in a cement plant. A Kalina Cycle power plant offers the best environmentally friendly alternative for power generation from low-grade waste heat. It maximizes kW-hrs generated using a closed loop system to recover heat for electricity production without hazard to the environment. The Kalina Cycle uses a mixture of ammonia and water as its working fluid; a common solution used extensively world wide for refrigeration plants. In the event of an accidental release, ammonia is considered a biodegradable fluid. It does not contribute to photochemical smog, global pollution or global warming; and will not deplete the ozone layer. Its use as an industrial fluid is well documented with a proven track record for safety in industrial plants. This paper is a summary of Kalina Cycle Technology for cement plant waste heat applications. Specific plant designs are referenced to present a summary of the power plant systems and to describe the financial advantages of the Kalina Cycle waste heat power plant to the cement plant owner.