| Abstract [eng] |
Urea is the most popular bulk nitrogen fertilizers. The main problem encountered when using urea fertilizers is the leaching of elements into groundwater. The last 30 years of use of urea are aimed at developing various new technologies that would help control the solubility of urea in the soil, thereby reducing the negative impact of this chemical compound on the environment. The aim of this project is to select suitable materials for the production of controlled-release coatings on the basis of literature data on urea pellet coating technologies and materials used in the production of coatings and to design a controlled-release technology for the production of granular urea. In the research part of the project, urea granules were coated with a molasses-based coating with embedded microelectets, thus not only slowing down the leaching of urea elements, but also adding trace elements to the composition which are very important for the vegetation of plants and amount of yield. In this part, the main properties of coated urea granules were studied: hygroscopicity, strength of the granules, bulk and compacted density of granules, moisture content in the pellet and others. An analysis of SEM-EDS was also carried out, indicating the quality of coating urea granules. In the engineering part of the project, technological calculations were carried out for the main installation of the coating process - the pseudo-boiling layer device, material balances were drawn up and the heat exchange area of the primary pellet heat exchanger-preheater was calculated. Based on the results of the calculations, a pseudo-boiling layer coating device, technologies for the preparation of the coating solution, as well as the final processing process of the coated granules were designed. An urea production building with facilities, as well as a plan of the surrounding plot design, also an economic and environmental calculations were also done. In the occupational safety and health part of the project, an occupational risk assessment was carried out, safe production, occupational hygiene and fire safety were assessed. In accordance with the current fire safety legislation, an evacuation plan was drawn up with the main and backup evacuation road, marked with hazardous areas of the building and fire-fighting equipment locations. |
