Modelling of apparel life cycle for achieving sustainability

Global per capita apparel consumption and the apparel disposal rate are continually expanding. It is expected that global apparel consumption will increase by 63% between 2015 and 2030. As a result, environmental impact will increase significantly and the uses of energy, chemicals and resources, as well as waste generation, are major environmental concerns for this sector. To quantify the sustainability of the apparel supply chain in a more sustainable way, an environmental impact assessment of apparel consumption and apparel disposal is necessary to achieve sustainability throughout the apparel life cycle. The aim of this thesis is therefore to develop a life cycle environmental impact assessment model of apparel consumption and apparel waste disposal. Life cycle assessment (LCA) is an extensively used technique for environmental impact assessment of any product or process. This study assesses life cycle environmental impact of apparel consumption and apparel waste disposal. The apparel consumption scenario in Australia is considered, coupled with the production phase in overseas, international transportation, consumer use and end of life in order to quantify the environmental flows. Such a life cycle assessment study has not been formally undertaken in the case of to Australia. The life cycle of apparel incorporates four phases: production, transportation, consumer use and end of life. The environmental impact categories assessed for this study are climate change potential (CCP), acidification potential (AP), abiotic depletion (ADP), water depletion (WD) and agricultural land occupation (ALO).

The model developed in this study has determined the overall environmental impact of each impact category and the contribution of each phase, the unit process, and the contribution based on fibre type and apparel type. It also determines per capita impact contribution to selected impact categories. Per capita impact contribution to CCP, AP, WD, ADP and ALO is estimated as 698.07 kg CO2eq, 3.09 kg SO2eq, 22.89 m3, 2878.68 MJ and 119.97 m2a, respectively. This study reveals that per capita apparel consumption in Australia increased by about 21% between 2010 and 2018, and per capita environmental impact increased with the increase of per capita apparel consumption. This LCA study has found that around 58% of the impact of CCP is caused by the production phase. The main contributors to the production phase are the extraction of raw fibres and the use of energy in textile processing, particularly in yarn production. The production phase contributes more than 80% of the impact of WD, ADP, AP and ALO in terms of total consumption. Energy use in textile processing is the main contributor for AP and ADP. This study determines that the consumer use phase contributes a larger proportion of the environmental impact of CCP, at 38.14%, which is mainly associated with consumer stage washing, drying and ironing, and this represents a significant opportunity to reduce CCP impact by changing consumer behaviour in apparel care.

This study identified possible impact improvement options in terms of production and consumer use. Also, a comparative analysis of the potentiality of environmental impact reduction of these options has been performed. It has been identified that the use of recycled fibre, organic fibre, energy-efficient textile processing technology, reducing process waste, increasing apparel lifetime, using energy-efficient washing machines, and reducing the frequency of apparel washing are the most promising options for impact reduction. It also found that, among all options, the use of organic cotton fibre and increasing the service lifetime of apparel are the most potential options for impact reduction in terms of production stage and use stage, respectively. The assessment result of impact improvement options provided will be useful for decision making on how to include them in the apparel life cycle for impact reduction.

Landfilling is a common apparel waste management option and many valuable resources ended up in landfill. Recycling of discarded textile waste to other value-added products is the best option to recover these resources. It is important, however, to know the environmental impact credit or burden of various recycling options, so that any additional impact will not be added by the recycling process. This study shows that the landfill process of discarded natural fibre apparel waste contributes environmental impact credit, which is credited from the power generation from landfill methane gas captured. This study also shows that environmental benefit from the landfill process of discarded apparel depends on the ratio of natural fibre to synthetic fibre in the discarded apparel. Further, it depends on the methane capture rate from the degradation of materials in the landfill. Improvements in the management of the landfill process can increase the environmental benefit from the landfill of discarded apparel. Incorporating recycling within apparel waste management can potentially create environmental benefit. This study identifies that, among the selected alternative recycling options, the recycling option of industrial cleaning wipes shows the highest impact savings, followed by recycling of cotton fibre, insulation material and polyester raw material.

Australia has a good record in kerbside municipal solid waste (MSW) recycling, mainly for masonry materials, metals, packaging materials, plastic and glass. However, recycling is very limited for textile waste. Since textiles are almost 100% recyclable. Therefore, priority needs to be given to include textile waste recycling for an environmentally conscious business model. The knowledge generated from this study can be utilized in policy recommendations or decisions as to which types of recycling or handling options (for example, collection as MSW for landfill or by recyclers for recycling) can be prioritised in the future.