Integration of LCA in a thermo-economic model for multi-objective process optimization of SNG production from woody biomass

This paper presents a methodology to integrate life cycle assessment (LCA) in models used to design energy conversion systems. It is illustrated by an application to a thermo-economic model for the multi-objective optimization of synthetic natural gas (SNG) production from woody biomass. The life cycle inventory (LCI) is written as a function of the parameters of the thermo-economic model. The obtained environmental indicators from the Life Cycle Impact Assessment (LCIA) are thus adapted to process design and scale. The conceived thermo-environomic model allows for taking into account the environmental impacts as a criterion in addition to economic and thermodynamic criteria in the process design and optimization.

Martin Gassner, Léda Gerber, François Maréchal

2009

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

Martin Gassner, Léda Gerber, François Maréchal

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.

Elsevier2011

Integration of Life Cycle Assessment in the conceptual design of renewable energy conversion systems

Léda Gerber

Life Cycle Assessment (LCA) is a well-established methodology that has been extensively used for the environmental evaluation of emerging technologies in the field of renewable energy conversion systems. In order to identify effective solutions for impact mitigation already at the conceptual process design stage, it is necessary to take into account the environmental aspects in the process design procedure, in consistency with economic and thermodynamic criteria. This thesis presents a systematic methodology for the integration of LCA in the conceptual design of renewable energy systems, using process design, process integration and multi-objective optimization techniques. The developed methodology is illustrated by three application case studies. The first one concerns the evaluation of different candidate technologies for the combined production of Synthetic Natural Gas and electricity from lignocellulosic biomass by thermochemical conversion. The second case study treats of the environomic optimal configurations of Enhanced Geothermal Systems for combined heat and power production, considering different potential conversion technologies. The third case study deals with the design and the synthesis of an urban energy system, accounting for the different energy services to be supplied, the different potential resources, the candidate conversion technologies, and the waste to be treated. In this last case study, the overall supply chains from resources or wastes to services are synthesized, accounting for the industrial ecology possibilities. A first major outcome of these application case studies is that accounting for the process integration in the evaluation of the environmental impacts leads to an important impact reduction. Secondly, the developed methodology allows for calculating the trade-offs between the environmental criteria and the thermo-economic ones. Therefore, the optimal promising configurations of an emerging technology or of a system considering its environmental performances can be identified. Finally, it is demonstrated that integrating the environmental impacts in the process design procedure leads to a different decision-making than if only thermo-economic criteria are considered.

EPFL2012

Integration of Life Cycle Assessment in the conceptual design of renewable energy conversion systems

Léda Gerber

EPFL2012