Modeling the Release of Urea from Coated Urea: The Constant Release Stage

Abstract:

Controlled release fertilizer (CRF) plays an important role in nutrient loss prevention by plants and its utilization enhancement. This study uses multi-diffusion model to simulate the release of urea for two coating materials: modified polyolefin (MPO) and latex film, based on COMSOL Multiphysics software. Effective diffusivity and lag time (t₀) are determined based on experimental data. Modeling results well simulate the experimental data of "constant release" stage. Standard error of estimate (SEE) ranges from 0.012 - 0.017 for MPO and 0.0316 for Latex film. The validated model is then utilized to study the effect of coating thickness (l), saturated urea concentration (C_sat) and effective diffusivity (D_e) on the urea release profile. Release time increase with increasing coating thickness or decreasing saturated urea concentration, effective diffusivity. In addition, a change in effective diffusivity does not make significant change in percentage of urea at the end of "constant release" stage.

• Periodical: Advanced Materials Research (Volume 970)
• Pages: 166-171
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.970.166
• Online since: June 2014
• Authors: Thanh H. Trinh*, Ku Zilati Ku Shaari, Anis Shuib, Lukman Ismail, Abdul Basit, Babar Azeem
• Keywords: Finite Element Method (FEM), Multi-Diffusion Modeling, Urea Diffusion, Urea Release

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