Master's Thesis : Life cycle assessment of a mineral fertilizer produce by Prayon

Abstract

This master's thesis is focus on the analysis of a specific type of fertilizer, that is produced by the company Prayon on its Engis site. This company is specialized in the production of phosphoric acid. This fertilizer is called NP 12-27 for 12% of ammonia and 27% of P2O5. It is produced by using phosphoric acid, MARP (monoammonium residual phosphate, a co-ptoduct of phosphoric acid). The first two are produced by Prayon, whereas ammonia is brought at another company. These three raw materials are mix together to synthesis the fertilizer. Due to the growing preoccupation about the environment and to the population growth that increase the food need and also the demand of fertilizers, having a clear understanding of the environmental impact of the production of NP 12-27 is important. Therefore, it has been analysed using the LCA method. LCA identifies and quantifies the energy and materials used and wastes released to the environment and assesses the impact of those inputs and outputs. The results have been calculated with the CML method. This analysis was compared to another LCA performed with the ReCiPe method to check the robustness of the results. Different types of allocations were carried out on a specific type of by-product called MARP. Thanks to this LCA, it was found that the elements with the greatest environmental impact are primarily ammonia over the abiotic depletion (fossil fuel) and the global warming. This is the only elements that does not come from the company. The second element having the greatest impact is the MARP of Puurs, especially in abiotic depletion, marine ecotoxicity and eutrophication The NP 12-27 can be of great interest, because, compared to another fertiliser taken into the ecoinvent database, it has less impact over nearly all the impact category except the eutrophication where the impact is bigger. The main advantage of this fertiliser is that it enhances the value of a product which was not very useful.