This book overviews combustion technologies and novel burner designs for reduced emissions and better fuel economy. It covers the recently developed enhanced design burners for higher turndown and lower NOx emissions, including the dual annular counter rotating swirl (DACRS) and enhanced vortex/environmental (EV) burners. The concept of flame stratification, i.e., heterogenization of the overall equivalence ratio, is introduced to widen the operability, control the emissions, and improve the turndown ratio of combustors. The recent developments and challenges toward the application of hydrogen combustion in the industrial combustion systems are introduced. Moreover, energy and hydrogen production in novel membrane reactors are reviewed in this book.