This book is a comprehensi ve and illustrated work on high temperature air combustion (here called HiTAC), which has revolutionized our paradigm on the use of all kinds of fossil, alternative, waste, and derived fuels for energy conversion and energy utilization in industry. Significant experimental knowledge and insights from many practical devices have resulted in the utilization of HiTAC technology for many applications. The traditional definition of flame is that which gives heat and light during chemical reaction between reactants. However, under certain conditions with some fuels, this definition of flame can be revised