Comparative cradle-to-grave life cycle assessment and water footprint scarcity of two packaging materials for carbonated beverages (polyethylene terephthalate versus glass) : a case study for a Lebanese industry

Abstract

Environmental problems such as climate change, water scarcity and natural resources depletion are rising. Solutions to such issues require the application of techniques based on sustainable development. Industrial sectors contribute to environmental problems due to the reliance on fossil fuels which are a non-renewable energy source that causes the emissions of greenhouse gases and other pollutants, affecting the climate and ecosystems. The carbonated beverages sector, in particular, is also one of the major sources of waste. This is especially due to the usage of packaging materials in the absence of proper waste management techniques. The purpose of this study is to compare the life cycle environmental impacts of two different packaging materials for a carbonated beverage: polyethylene terephthalate (PET) versus returnable glass bottles. This is done using the life cycle assessment (LCA) method to evaluate and assess the environmental impacts through a cradle-to-grave approach, i.e. from raw material acquisition till end-of-life. Climate change, ecosystem quality, human health, resources and water scarcity impacts are determined and analyzed for the two types of packaging. In addition to performing the LCA for those packaging types for the first time in Lebanon for a beverage industry and assessing the water scarcity impacts, the originality of this research is highlighted through the modeling of the different waste scenarios. The database library used is ecoinvent 2019 and the software used to model the life cycle inventory is Simapro. The IMPACT2002+ method is used to evaluate all of the environmental impacts except water scarcity which is assessed using the Water Use in Life Cycle Assessment (WULCA) method. The main contributor to the PET assembly is the manufacturing of the preform tubes which contributes, for instance, to ionizing radiation (88%) and mineral extraction (95%). On the other hand, for the assembly of the glass bottles, their manufacturing contributes for example to non-renewable energy (97%) and terrestrial ecotoxicity (93%), while the manufacturing of crowns presents a contribution to mineral extraction (43%). At the level of the life cycle, in addition to the assembly, the waste scenario adopted for the PET bottle is a main contributor to aquatic eutrophication (97%). For the glass packaging, the bottle assembly is a main contributor to global warming (91%) and land occupation (93%). As for the water scarcity footprint, it is estimated at 6.92E-02 m3 world equivalent for the PET bottle due to the manufacturing of the preforms and the rinsing process and 4.96E-01 m3 world equivalent for the two returnable glass bottles due to the washing process at the industry.The results show that for the waste scenario considered (8% recycling, 50% landfilling, 21% open-dumping and 21% open-burning), the returnable glass bottles present a lower contribution to the environmental impacts when compared to the PET bottle. The larger contribution of the PET bottle is mainly due to the waste scenario adopted, especially open-burning and open-dumping. It is worth mentioning that the results depend greatly on the percentages of the waste treatments implemented. In fact, by increasing the recycling rate of PET, the results are shifted and PET becomes better than glass in 10 out of 15 categories.