Prospective Life Cycle Assessment Based on System Dynamics Approach: A Case Study on the Large-Scale Centrifugal Compressor

Abstract

The deficiency of temporal information in life cycle assessment (LCA) may misrepresent the environmental impacts of products throughout the life cycle or at a particular time in the future. For the environmental assessment of energy-consuming products, background data obtained from the LCA database fail to incorporate emissions or extractions reflecting the future situation. To overcome this knowledge gap, we developed a system dynamics (SD) model to predict the evolution of energy structure in China till 2030 and further determined the time-varying emissions of unit electric power combined with the ecoinvent 3.1 database. Additionally, dynamic characterization factors (CFs) of global warming potential (GWP) were integrated into the life cycle impact assessment (LCIA). This study took the PCL803 large-scale centrifugal compressor as an illustrative example in which the temporal-dependent electricity was included in the dynamic life cycle inventory and the dynamic CFs of GWP were included in the LCIA. Environmental impacts were quantified and compared using the traditional and prospective LCA. Results indicated that the environmental burdens under the electricity variation were approximately 13% less than those of conventional LCA, and the GWP under dynamic CFs would be further reduced by 14.5%. The results confirmed that, when socio-economic progress, technical improvement, and dynamic CFs are not considered, the environmental assessment will lead to an overestimation of environmental loads. Therefore, the relevant time-varying parameters should be considered for accurate assessment.