Normalization factor database for life cycle impact assessment in China

Abstract

Normalization is applied to calculate the magnitude of an impact relative to the total impact of a given reference in Life Cycle Assessment (LCA). Normalized profiles of environmental impacts depend on geographical areas due to differences in the industrial and economic activities. So far, Normalization factors for China are not developed to conduct life cycle assessment analysis. The purpose of this research is to propose a database of normalization factors (NFs) covering 18 environmental impact categories in a Chinese context to fill the research gap. To establish the local database, we collected the domestic inventory of emission and resources extraction in China with necessary data extrapolation and then calculated the normalization factors based on the international model ReCiPe2016. Furthermore, normalization factors for each impact category are differentiated into individual and national levels, and the substance contribution proportion of the 18 environmental impact categories is quantified. In addition, we used the Data Quality Indicator (DQI) model to evaluate the data source of impact categories, while analyzing the uncertainty of normalization factors quantitatively based on the evaluation result. The results of the quantitative analyses showed uncertainty intervals for the normalization factors. It was found that ionizing radiation and toxicity got the largest uncertainty intervals among the normalization factors for all impact categories, owing to the low completeness of the inventory of substances in those two impact categories. According to the data quality indicators of impact categories, we located the data gap in domestic inventory and proposed measures to promote comprehensiveness of inventory. This China Normalization Factors Database provides the LCA researchers with a starting point for a subsequent weighing step and improves the accuracy of LCA study at the Chinese territory.