A stochastic environmental mode! to deal with uncertainty in life cycle impact assessment

摘要

Life cycle assessment (LCA) is the most applied methodology to compare the environmental impacts of different products and processes.As uncertainty may be present in the first three steps of an LCA an uncertainty analysis should be considered allowing higher confidence in the results.However, few LCA studies include this analysis and when it is included is mostly applied to the LCI step of an LCA.Thus, the goal of this study is to develop a methodology to apply uncertainty analysis on the characterization factors used at the midpoint level in the LCIA step.The methodology employs Monte Carlo simulation as the stochastic modelling technique.A case study comparing the use of softwood and hardwood in the production of unbleached Kraft pulp is utilised to better explain the application of the developed methodology.As main results it can be concluded that the use of softwood as a raw material is overall worse for the environment than the use of hardwood when considering the production of unbleached Kraft pulp.