Packed bed columns are largely employed for absorption, desorption, rectification and direct heat transfer processes in chemical and food industry, environmental protection and also processes in thermal power stations like water purification, flue gas heat utilization and SO2 removal. These Separation processes, are estimated to account for 40-70 per cent of capital and operating costs in process industry. Packed bed columns are widely employed in this area. Their usage also for direct heat transfer between gas and liquid, enlarge their importance. They are the best apparatuses, from thermodynamical point of view, for mass and heat transfer processes between gas and liquid phase. Their wide spreading is due to low capital investments and operating costs. Since 1995, there has not been published a specialised book in this area, and this is a period of quick development of packed columns. "Packed Bed Columns" reflects the state of this field including the author's experience on creating and investigating of new packings, column internals and industrial columns. This book considers the theories of mass transfer processes and shows how they help the construction of highly effective packings. It provides complete information about the performance characteristics of different modern types of highly effective packings. It considers the models for calculation and areas of their application.