Large Volume Inorganic Chemicals - Ammonia ... - ammk-rks.net

Chapter 88.4.8 Heat integration in stripping plantsDescriptionHeat integration between the synthesis section and downstream sections reduces the energyrequirement. MP steam is supplied to the synthesis to decompose and separate excess NH 3 andcarbamate in the stripper. The stripped CO 2 and NH 3 gas mixture is sent to the carbamatecondenser and the condensation heat is recovered as LP steam or by process to process heatexchange in the MP and LP decomposition sections, and the evaporation stage(s). Depending onthe degree of integration, the urea plant exports LP steam.See also Section 8.4.7 “Revamping conventional plants with stripping technology”.LP steam 5.5 barSynthesis,stripping,carbamate condenserMP steam15 barHEHEHEDecompositionMPDecompositionpre-evaporationLPEvaporationOtherTurbineElectricity for CO 2compressorHP steam40 barExportFigure 8.3: Example for the heat integration on a total recycling stripping plantHE: process to process heat exchangeBased on [124, Stamicarbon, 2004]. Similar: [122, Toyo, 2002, 126, Snamprogetti, 1999]Achieved environmental benefits• reduced energy requirements.In a modern total recycling process, conversion of ammonia to a solid urea requires 3.3GJ/tonne urea. It is assumed that the average requirement for European plants is 4.1 GJ/tonneurea [107, Kongshaug, 1998].Cross-media effectsNone believed likely.Operational dataNo specific information provided.350 Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers