The main objective of this book is mass transfer augmentation processes to reduce equipment size, and operating costs, and increase throughputs. Various techniques have been adopted to obtain enhancements. Following are the techniques.1) surface promoters 2) insert promoters 3) swirl generators 4) different geometric shaped conduits 5) additives 6) Pulsation or rotation of fluid 7) Vibration of the reacting surface 8) Application of two or three phase flow and 9) Application of magnetic and electric fields. Insert promoters have the advantages of easy fabrication, operation, and maintenance. In the case of insert promoters, the flow fields vary with the geometry of the promoter and these promoters are generally complex and are not readily amenable to mathematical analysis. In such cases, one has to resort to obtaining accurate experimental data, analyzing the data in dimensionless groups, and appropriately relating them. In order to achieve the objective, an assembly of the Harrow disc is used as an insert promoter.