Size diameter prediction of urea fertilizer microcapsules using dimensionless numbers: The influence of chitosan solution concentration and stirring speed

The aim of this study is to compose empirical equation of Reynold (Re) and Weber (We) numbers predicting the size of urea fertilizer microcapsules based on concentration of chitosan solution and stirring speed. Urea fertilizer microcapsules are prepared by applying emulsion cross-linking method using chitosan solution as a wall material and glutaraldehyde saturated toluene (GST) as a crosslinking agent. The diameter of microcapsules that are formed is analyzed using digital microscope. To predict the size of urea fertilizer microcapsules, this study uses correlation of empirical equation of dimensionless numbers proposed by Reynold (Re) and Weber (We) number, then the size of the calculated microcapsules compared with the results of research. The obtained equation is used to calculate microcapsules diameter and compare it to research data. The result is it has a small % error for parameters, the influence of chitosan solution concentration and stirring speed is 0,58% and 1,29%.