Coupling life cycle assessment with process simulation for ecodesign of chemical processes

Because of the central position of the chemical industries along the value chain, process design has a pivotal role, involving many decision makers and multiple levels of decisions. To tackle the environmental concern at source, this article presents a methodological framework for process ecodesign, coupling flowsheeting simulators both for production and energy processes with a Life Cycle Assessment module that generalizes and automates the evaluation of environmental impacts. The life cycle inventory is carried out through the combined use of mass and energy balances resulting both from the global simulation of the process and its associated energy production requirement and from the use of inventory database (i.e., Ecoinvent v3) embedded in the Life Cycle Assessment software tool used (SimaPro). Different process alternatives can thus be evaluated in a systematic way and the energy-related emissions for any given process that match exactly the real situation can be computed without introducing a bias in the estimation. Through comparisons between a case base and process alternatives, a systematic decision can be made in terms of whether a solution is moving the process towards a more sustainable operation. The effectiveness of the proposed framework is first illustrated through the case study of benzene production and second, by a biodiesel production process from waste vegetable oils which is one of the foremost alternative fuels to those refined from petroleum products. (c) 2017 American Institute of Chemical Engineers Environ Prog, 37: 777-796, 2018