Systematic integration of LCA in process systems design: Application to combined fuel and electricity production from lignocellulosic biomass

• Published in: Computers & chemical engineering 2011-07, Vol.35 (7), p.1265-1280
• Main Authors: Gerber, Léda, Gassner, Martin, Maréchal, François
• Format: Article
• Language: English
• Subjects: Applied sciences; Biofuels; Biomass; Decision theory. Utility theory; Electricity; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Life cycle assessment; Life cycle engineering; Mathematical analysis; Mathematical models; Mechanical engineering. Machine design; Methodology; Natural energy; Operational research and scientific management; Operational research. Management science; Optimization; Process systems design; Rational use of energy: conservation and recovery of energy; Synthetic natural gas
• ISSN: 0098-1354; 1873-4375
• DOI: 10.1016/j.compchemeng.2010.11.012

▶ Systematic methodology to integrate life cycle assessment in process systems design. ▶ Applied to combined fuel and power production from biomass in multiobjective optimization framework. ▶ Importance of proper choice of objective functions and functional unit in polygeneration systems. ▶ Results show influence of process integration, logistics and support materials on LCA indicators. ▶ Though increased efficiency reduces impact, thermodynamic and environmental optima do not correspond. This paper presents a methodology to integrate life cycle assessment (LCA) in thermo-economic models used for the optimal conceptual design of energy conversion systems. It is illustrated by an application to a thermo-economic model developed for the multi-objective optimization of combined synthetic natural gas (SNG) and electricity production from lignocellulosic biomass. The life cycle inventory (LCI) is written as a function of the parameters of the thermo-economic model. In this way, the obtained environmental indicators from the life cycle impact assessment (LCIA) are calculated as a function of the decision variables of process design. The LCIA results obtained with the developed methodology are compared with the results obtained by a conventional LCA of the same process. Then, a multi-objective environomic (i.e. thermodynamic, economic, environmental) optimization of the process superstructure is performed. The results highlight the important effects of process configuration, integration, efficiency and scale on the environmental impacts.