From a literature review to a framework for environmental process impact assessment index

Several methods to evaluate the environmental process impact assessment of industrial chemical processes have been presented in the literature. Although these methods follow the same steps (usually, characterisation, normalisation and weighting), each method addresses different impact categories, considering specific nomenclatures and using different taxonomies to classify their outputs. When industrial chemical processes are being assessed by several methods, different results are obtained. The comparison of these non-standardised results turns out to be a difficult task. This work has two main contributions that help in the choice of the most appropriate method to be used. First, standardise the taxonomy used by the different methods and second, propose a quantitative framework that combines different methods into a final score. Therefore, it is suggested a standard taxonomy, which allows to report the output of the different methods in a systematic way. A new concept called impact categorical groups is also proposed. These groups aggregate similar impact categories presented by different methods, and therefore allow the comparison of the obtained results by different methods. A framework to aggregate impact category indicators from different methods into a final score (index) is also presented. This framework also suggests a path to determine the best method to be applied and provides an insight on the weighting factors that should be considered in the aggregation of the different indicators into the final index. The basis for the proposed achievements was an extensive literature review, which includes 25 methods for environmental process impact assessment.