Flares are the major sources of air pollution. In some cases the emission of heavy pollutants could have destructive effects on the water and soil which cause the most serious environmental problems. In this book, the heat exchangers were designed on the flare networks to separate the heavier pollutants of plants before flaring. The proposed designs were simulated and evaluated from economic and environmental aspects. The results of this book approved the necessity of the heat exchangers application to address the environmental issues and will guide the researchers to investigate the possibility of heat exchanger installation to reduce environmental problems of the flare systems.