Process simulation and life cycle analysis in the dairy industry – application to milk concentration

International audienceMilk concentration and spray drying are highly energy-intensive operations, for which energy consumption accounts for about 25% of the French dairy processing industry. A major challenge consists then in the design and development of sustainable dairy concentration processes which integrate technical, economic and environmental criteria. For this purpose, systems oriented tools have already been developed in the chemical industry by using a systemic approach combining modelling, simulation, and optimisation. Despite the proximity of chemical with food and bioengineering sectors, the utilization of such an approach for the modelling of dairy processes suffers from a lack of process models, more particularly when the whole process is considered and when concentration processes are involved. In that context, this work constitutes a preliminary study towards the development of a methodological framework for modelling and optimizing dairy processes. The proposed strategy consists in the combination of a chemical process simulator (ASPEN PLUS 7.3, AspenTech, Inc.) with an environmental model based on Life Cycle Assessment concepts. The simulated process concerns milk powder production, and more particularly milk concentration prior to drying, involving pre-heating, pasteurization, and evaporation steps. The process model performances are assessed through a sensitivity study on the number of effects in the evaporator, and the environmental impacts associated to the various steam requirements involved are quantified according to several scenarios