In recent years, computational fluid dynamics (CFD) has been used increasingly to improve process design capabilities in many industrial applications, including industrial drying processes. Drying of food and beverage products, industrial and municipal wastewater sludge, and other manufacturing and environmental products is done regularly in order to enhance the quality and life span of these products and to facilitate their use, storage, and transportation. With recent advancements in mathematical techniques and computer hardware, CFD has been found to be successful in predicting the drying phenomenon in various types of industrial dryers, which utilize all forms of drying operations including spray, freeze, and thermal drying techniques. The CFD solutions are being used to optimize and develop equipment and processing strategies in the drying industry, replacing expensive and time-consuming experimentations. However, a comprehensive review on the application of CFD for the design, study, and evaluation of industrial dryers is not yet available. A comprehensive review of the current literature on the use of CFD models in both industrial and lab-scale drying applications is presented in this article. The use of Eulerian-Eulerian and Eulerian-Lagrangian models in the study of the drying kinetics for gas–solid multiphase flow systems is fully discussed. Merits and disadvantages of using various CFD models in the design of industrial dryers are illustrated and the scope of their applicability is also discussed.

This work demonstrated a simple and green method for the synthesis of tin phosphate (SnP) catalysts for glucose to HMF transformation. In this process, SnP catalysts with various P/Sn mole ratios were prepared by solid-state grinding of a mixture of SnCl₄·5H₂O and NaH₂PO₄·2H₂O at room temperature, followed by drying with or without calcination. Physicochemical properties of the obtained SnP catalysts were investigated using N₂-physisorption, XRD, FT-IR, Py-IR, NH₃-TPD, and XPS techniques. The characterization studies showed that varying P/Sn ratio affected the textural and surface acid properties of the SnP catalysts. The activity of these catalysts was evaluated for dehydration of glucose for HMF production in water using recyclable low boiling point organic solvent THF as HMF extracting solvent. The experimental results revealed that the catalytic activity of SnP catalysts depended on the P/Sn ratio. Under the optimized reaction conditions, 98% glucose conversion, and 61% HMF yield were achieved over as-synthesized SnP-1 catalyst with P/Sn mole ratio of 1.0. The high catalytic activity of the SnP-1 catalyst can be attributed to its high acidity and the presence of water tolerant Brønsted and Lewis acid sites. Furthermore, the catalytic activity of SnP-1 catalyst is retained even after four cycles indicating its good catalytic stability.