Life Cycle Assessment of Waste Glass Geopolymerization for the Production of Sustainable Construction Materials

Replacing conventional materials with new recycled materials is one of the goals of sustainable development, as it promotes the creation of environmentally friendly products while reducing the amount of waste to be treated. A common recyclable waste stream associated with urban living is waste glass, which typically comes from packaging or product containers. Although most of this stream can be reused and/or recycled, it is worth exploring alternative uses, especially for areas with high fluctuations in waste glass production. An example would be the sudden increase in waste glass in tourist areas during the high season. To this end, the present work presents the results from the life cycle assessment of waste glass geopolymerization for the production of cement tiles. The methodology includes the estimation of mass and energy balances by dividing the whole process into several sub-processes (NaOH addition, energy consumption, etc.). The NaOH addition was found to be the most burden-intensive process, with a total damage of 9 × 10⁻⁵ DALY per ton of waste glass in the human health category, while a minor contribution in all damage categories was attributed to process electricity demands (7.7 to 19.4%). By comparing the geopolymerization process with conventional recycling, an environmental benefit of 20 mPt and 26 kg CO₂ per ton of waste glass was demonstrated, indicating the process’s expediency. The present study is a valuable tool for the up-scaling of processes towards a circular economy.