Abstract: Life cycle assessment (LCA) is a comprehensive method to identify and evaluate the environmental impact of a product or a process throughout the life cycle, which can effectively identify the key stages of the environmental impact of a product's life cycle and thus provide important and accurate guidance for the development of energy conservation and emission reduction strategies. Due to the long and complex supply chain and manufacturing processes, the textile industry is inevitably one of the most pollutant industries around the world. Therefore, conducting life cycle assessment and selecting the appropriate LCA systems and databases for textile products and production processes are of vital significance. China is one of the largest producers and consumers of textile products around the world. LCA of textile products is an effective tool to quantify the environmental impacts generated by the production and consumption of textile products, which further provides valid references for green and low-carbon textile product design, production and consumption. Data collection and result evaluation are two key aspects of product LCA. Using LCA system and its built-in database of impact factors for energy, materials and other input lists can greatly improve the efficiency and accuracy of LCA for products.
In order to conduct a systematic and comprehensive analysis of LCA systems and databases for textile products, we firstly searched literature pertaining to product LCA research on China National Knowledge Infrastructure (CNKI) and Web of Science and summarized the product LCA systems and databases applied in the literature. Considering that LCA of textile products is receiving increasing attention and research, we then searched the literature on LCA research of textile products and analyzed the assessment systems and databases applied in literature. According to the fiber category, the literature found was classified and the impact models and LCA databases used were listed and compared. In addition, we systematically analyzed and compared the accounting interfaces of the current LCA systems of textile products, including the tree interface, flowchart interface and Sankey diagram interface and so on. The built-in Ecoinvent database, Gabi database, and IDEMAT database of Simapro and Gabi systems contain most of the material and energy inventory data required for conducting LCA of textile products. Thus, Simapro and Gabi systems are most widely used in LCA studies of textile products among the current LCA systems. Database and the number of impact assessment models, characterization factors, normalization factors as well as weighting factors applied in the research literature of LCA of textile products were compared as well. And we took the characterization factor of marine ecotoxicity and normalization factors of EDIP model for example. On the whole, the number of built-in databases and impact assessment models in the LCA system directly determines the comprehensiveness and accuracy of LCA results. LCA systems often have the same sorts of characterization factors with different values between built-in databases. Taking the Simapro and Gabi systems which are widely used in LCA studies of textile products as examples, we compared the marine ecotoxicity characterization factors of the ReCiFe2016 database and normalization factors of EDIP model within the two evaluation systems. In addition, we analyzed the reasons and influencing factors for the differences in weighting factors in different LCA systems. The inconsistency of characterization factors, normalization factors, and weighting factors among major LCA systems and databases, as well as the different numbers of databases and impact assessment models lead to differences in results when LCA studies are conducted for the same textile product using different LCA systems and databases. The results show that in terms of cases of LCA of textile products, Simapro system and Gabi system are the systems used most commonly, accounting for 53.77% in total. In terms of impact evaluation databases used in cases of LCA of textiles, Ecoinvent database and Gabi database are the databases used most commonly in the LCA of textile products, accounting for 79.24% in total. Moreover, the built-in databases of Simapro and Gabi systems have the same type of characterization factors, normalization factors, and weighting factors with different values, resulting in discrepancy between the life cycle assessment results for the same textile products. The reasons for the differences include the facts that the Simapro and Gabi systems are developed by separate institutions, and that the production scale and technology levels in the developers' regions, and the conversion factors are different.
The differences between LCA systems and databases of pollutant emission channels and production scale, technology level, economic status, and environmental policies in the region are the main reasons for the different results when different LCA systems for LCA studies of textile products are used. By comprehensively considering the above factors, constructing an LCA system and database of textile products with regional features and a unified benchmark can improve the integrity and accuracy of the evaluation results.

Key words: textile products, life cycle assessment, evaluation system, impact evaluation, list database

摘要： 产品生命周期评价系统和数据库为高效、准确开展产品生命周期评价提供数据处理、结果量化和评价支撑。本文对纺织产品生命周期评价研究文献中应用的生命周期评价系统与数据库系统界面、数据库和影响评价模型数量、特征化因子、归一化因子、权重因子等进行了系统分析。结果表明：Simapro系统和Gabi系统是纺织产品生命周期评价案例使用最多的系统，总占比为53.77%；Ecoinvent数据库和Gabi database数据库是纺织产品生命周期评价案例使用最多的数据库，总占比为79.24%；Simapro系统和Gabi系统内置数据库有相同种类但数值不同的特征化因子、归一化因子、权重因子，导致使用两个系统针对同一纺织产品的生命周期评价结果存在差异；综合考虑污染物排放渠道和区域内生产规模、科技水平、经济状况、环保政策等因素，构建具有国家、区域、时间性质的纺织产品LCA数据库可以提高评价结果的完整性和准确性。

关键词: 纺织产品, 生命周期评价, 评价系统, 影响评价, 清单数据库