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(T/MC266) Life Cycle Assessment applied to industrial urea production. Revenga, Juan1, Romero, Teresa2, 1 2 ABSTRACT- Life Cycle Assessment (LCA) can identify possibilities to improve the environmental behaviour in the industry. LCA methodology helps in decision making process in engineering in two dimensions: making easy the selection between processes or technologies that permit improvement in environmental performance and connecting environmental and economic aspects. In this work, an LCA steps (according ISO 14040) is applied to industrial urea production, analysing the influence of different factors in environmental behaviour. Goal definition and scope: Identify the principal environmental aspects in industrial urea processes and select the best option for different products (wet, prills and dry product) and processes. Life-cycle inventory: Collection and processing data about energy and material inputs: use of energy (electricity, steam), cooling water and raw material (ammonia, carbon dioxide). Life-cycle impact analysis: assessing the environmental impacts associated with the different processes (resource use, global warming, acidification, eutrophication). Interpretation: evaluating opportunities to reduce energy consumption, raw materials, environmental impacts and select the best process. Ammonia and carbon dioxide are reacted together at high temperatures and pressures. The effluent from the synthesis reactor contains urea, water, ammonia and ammonium carbamate. In all urea processes, carbamate must be removed from the urea solution produced in the reactor. The differences in the various processes are in the way in which the carbamate is decomposed and removed from the product, and in the way in which the off-gases produced in the decomposition are treated. Process may be divided in following groups: a) Partial recycle (Stamicarbon), b) Total recycle (Chemico), c) Stripping processes (DSM, Snam-Progetti): d) Integrated route (Mitsui Toatsu). Results of the study show processes should be consider for environmental advantages -stripping process and integrated route-. At the same time, the model identifies which areas of the processes can be considered for the optimization, and shows that LCA can quantify environmental performance of a process. Key words: urea production, LCA |
