Response Surface Method in the Optimization of a Rotary Pan-Equipped process for Increased Efficiency of Slow-Release Coated Urea

Abstract

The high solubility of urea in water and its consequent leaching into the soil adversely prevents its full assimilation by plants. An improved slow-release process could effectively minimise the loss of fertilizer material and thus mitigate the associated environmental pollution. In this study, the effects of the operational variables on the efficiency of the urea coating process in a rotary pan have been systematically analysed. A mixture of gypsum-sulphur was used as the coating material with refined water as a binder. In order to comprehensively investigate the impact of each process variable on the efficiency and any potential interactions between them, the effects of particle size, coating material percentage, rotational speed of the pan, spray flow rate and the amount of sprayed water were investigated and analysed via a central composite design of experiments (DoE). The second-order polynomial model provided the best correlation for the experimental data. The predictive model was then used to estimate the efficiency of the coated urea as a function of the statistically-significant variables. The results revealed an increase in the efficiency of the coated urea from 22% to 35% (i.e., ~59%) when prepared under the optimum process conditions.

Effects of Environmental Stresses (Heat, Salt, Waterlogging) on Grain Yield and Associated Traits of Wheat under Application of Sulfur-Coated Urea

“…The controlled release of nitrogen fertilizer was key to the wheat plant growth, especially in waterlogged and salt stress. Many studies found that a higher grain yield can be attained by applying controlled-release SCU fertilization [23]. SCU increased grain yield efficiently by lowering rhizosphere pH, and the results were consistent with findings of a previous study [47].…”

“…One of the good slow-release nitrogen fertilizers is sulfur-coated urea (SCU), which promotes wheat growth and development. The wheat crop has a positive correlation between "S" and "N" elements [23]. The S element is a secondary and fungicide with acidic possessions that neutralize the alkalinity of soil [24].…”

Release Mechanisms and Kinetic Models of Gypsum–Sulfur–Zeolite-Coated Urea Sealed with Microcrystalline Wax for Regulated Dissolution

“…The coating of urea particles was performed in a stainless-steel rotary pan of 60 cm diameter and 12 cm pan height ( Scheme 1 ) at ambient conditions as previously described. 33 As shown in Table 3 , six different coating formulations, consisting of combinations of gypsum, sulfur, and zeolite at various compositions, were studied. It should be noted that although each component has been used as a coating material for SRFs, 30 , 38 in this study, gypsum plaster played another role as a binder, and it was therefore a base material in all formulations.…”

“…The dried coated urea granules were then collected for further studies. The other coating parameters and their corresponding values based on the previous study 33 are also summarized in Table 4 .…”

Special Issue on Performance Measurement and Optimization for Sustainable Production Processes Improvement

“…Eghbali Babadi et al [12] analyzed the operational variables effect on the urea coating process efficiency in a rotary pan. And Rozbroj et al [13] investigated cylindrical pellet size optimization using discrete element method model.…”