Introduction Drying is inherently a cross and multidisciplinary area because it requires optimal fusion of transport phenomena and materials science and the objective of drying is not only to supply heat and remove moisture from the material but to produce a dehydrated product of specific quality (Mujumdar, 2004) [1] . There are two main modes of drying used in the heat drying or pelletization processes; namely, direct and indirect modes. Each mode of drying has its merits and disadvantages and

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... the choice of dryer design and drying method varies according to the nature of the material to be handled, the final form of the product, and the operating and capital cost of the drying process. The drying of various materials at different conditions in a wide variety of industrial and technological applications is a necessary step either to obtain products that serve our daily needs or to facilitate and enhance some of the chemical reactions conducted in many engineering processes. Drying processes consume large amounts of energy; any improvement in existing dryer design and reduction in operating cost will be immensely beneficial for the industry. With the advance in technology and the high demands for large quantities of various industrial products, innovative drying technologies and sophisticated drying equipment are emerging and many of them remain to be in a developmental stage due to the ever increasing presence of new feedstock and wetted industrial products. During the past few decades, considerable efforts have been made to understand some of the chemical and physical changes that occur during the drying operation and to develop new methods for preventing undesirable quality losses. It is estimated that nearly 250 U.S. patents and 80 European patents related to drying are issued each year (Mujumdar, 2004) [1] . Currently, the method of drying does not end at the food processing industry but extends to a broad range of applications in the chemical, biochemical, pharmaceutical, and agricultural sectors. In a paper by Mujumdar and Wu (2008) [2] , the authors emphasized on the need for cost effective solutions that can push innovation and creativity in designing drying equipment and showed that a CFD approach can be one of these solutions. The collective effort of their research work along with other researchers in the drying industry using mathematical www.intechopen.com Mass Transfer in Chemical Engineering Processes