This document discusses waste heat recovery (WHR) systems in cement plants. It describes how WHR can utilize the industrial waste heat generated during cement production through combined heat and power or cogeneration systems to produce steam or electricity. It notes that the rotary kiln in cement plants reaches temperatures of 1300-2200°C but this heat is usually lost to the environment. WHR technologies like organic Rankine cycle and waste heat boilers can capture up to 25% of rejected flue gases and exhaust air to generate additional energy. Industries like cement, glass, steel and refineries are examples where WHR is commonly used. Tri-generation or combined heat, power and cooling systems are also mentioned that simultaneously produce electricity,