Life cycle assessment of horizontal-axis washing machines in China

Abstract

Currently, environmental sustainability of washing machines, one of the most popular household appliances in people’s daily life, has gained much attention from governments and suppliers due to resource and energy consumptions as well as emissions in the production, distribution, use, and disposal processes. Therefore, it is necessary to systematically evaluate the environmental impacts from a life cycle perspective to explore the sustainability improvement opportunities of washing machines especially for China, a major producer, exporter. and consumer. This study is conducted according to the International Organizations for Standardization’s 14040 standard series from cradle to grave. The research object is a Chinese-produced horizontal-axis washing machine. The production and recycling data mainly come from field investigations on representative firms, including both household appliance production and recycling firms in China. The use phase data are mainly from 1330 questionnaires about Chinese residents. The secondary data are supplemented from databases, literature, and authoritative technical manuals. The potential environmental impacts are evaluated using the CML2001 methodology built into the GaBi version 6.0 software. The hotspots throughout the life cycle of the washing machine are determined with the impact categories of abiotic depletion, acidification potential, global warming potential, photochemical ozone creation potential, eutrophication potential, and toxicity. The results show that the production and use phases are the main contributors to the environmental impacts dominated by electronics, plastic components, and electricity consumption as well as the wastewater discharge in use phase which brings eutrophication potential. While, the end-of-life phase brings recycling credits due to the recycling of materials such as copper, steel, and plastics. In particular, aluminum and copper consumption in the electronics, electricity consumption, and plastics used in injection molding of plastic parts, electricity consumption, and detergent use in use phase are the main hotspots based on the results of life cycle impact assessment. The use phase scenario analysis shows that water temperature is the most important factor that decides the environmental impacts because heating water consumes large amounts of electricity. This quantitative life cycle assessment can be a useful tool for decision-makers to understand the life cycle environmental impacts of Chinese washing machines and explore sustainability improvement opportunities, as well as help manufacturers identify priorities for actions from an environmental protection perspective.