%0 Journal Article %@ 00084034 %A Azeem, B. %A KuShaari, K. %A Man, Z. %A Trinh, T.H. %D 2017 %F scholars:8698 %I Wiley-Liss Inc. %J Canadian Journal of Chemical Engineering %K Diffusion in liquids; Fluidized bed process; Fluidized beds; Granulation; Metabolism; Nutrients; Plating; Size distribution; Starch; Thickness measurement; Urea, Coating homogeneity; Controlled release; Fluidized bed coating; Release characteristics; Starch coatings, Diffusion coatings %N 5 %P 849-862 %R 10.1002/cjce.22741 %T Nutrient release characteristics and coating homogeneity of biopolymer coated urea as a function of fluidized bed process variables %U https://khub.utp.edu.my/scholars/8698/ %V 95 %X The present study investigates the effect of fluid-bed process parameters on the diffusion coefficient of nitrogen release and coating homogeneity of controlled-release urea (CRU) produced in a rotary fluidized bed using polyvinyl-alcohol-modified starch as a coating material. An existing mathematical model was used to estimate the diffusion coefficient. The coefficient of variance of size distribution and coating mass variation are reported as a measure of coating homogeneity. Statistical analysis suggested that the most influential process variables that govern urea release characteristics and coating homogeneity were (a) fluidizing gas temperature and (b) coating time. A moderate spray rate combined with longer coating time yielded the lowest diffusion coefficient for nutrient release. Elutriation as the result of elevated fluidizing gas temperature allowed a higher diffusion coefficient due to lower coating thickness. Burst release patterns were observed for granules with coating imperfections. The augmented temperature of fluidizing gas had a negative effect on coating mass and size distribution of CRU granules but the influence of longer coating time was positive. © 2016 Canadian Society for Chemical Engineering %Z cited By 15