Analysis and Development of the Interpretation process in LCA

The objective of this work is to study interpretation as a procedure to use the quantitative results of a life-cycle inventory to compare process alternatives with the aim to conclude, whether or not significant differences exist with regard to the studied issues (individual emissions or impact categories). As a result of an introductory survey a procedure for quantitative interpretations is suggested, with data-quality scoring, statistical experimental planning, and multivariate data analysis as basic tools. The procedure has been tested on a case study of treatment of paper packaging waste, either by material recycling or by energy recovery (incineration). The inventory of an earlier study has been used. With the aid of what is called a conceptual model five variables, which could be presumed to have an influence on the environmental impact of paper packaging waste treatment, were identified. The choice of technology, material recycling or energy recovery, was one of these variables. Subsequently 36 scenario calculations, organised in an experimental matrix, were performed. The result was interpreted with the multivariate techniques principal component analysis (PCA), partial least-square modelling (PLS), and uncertainty analysis. The multivariate analysis made it possible to isolate the influence of the variable 'choice of technology' on the environmental impact of the system.