Life cycle assessment of silica aerogel produced from waste glass via ambient pressure drying method

Silica aerogels are excellent insulation materials, but they possess high embedded costs and their production includes many energy-intensive steps. A novel protocol developed to produce silica aerogel from waste soda lime glass via ambient pressure drying was assessed regarding sustainability. Upcycling waste materials and implementing a low-energy drying technique are aimed at increasing the sustainability of aerogels. This study presents a cradle-to-gate life cycle assessment (LCA) of this process on a laboratory scale (reactor volume of 0.5 l) as well as on a modeled industrial scale (reactor volumes of 100 l and 1000 l). The environmental impacts associated with each scale, as well as with each step of the production, were calculated and summarized with an environmental cost indicator in euros for each process. Potential end-of-life scenarios were considered to explore waste treatment approaches. Results show that electricity consumption is a major contributor to environmental impact, especially at the laboratory scale. However, at the industrial scale, efficiency is significantly improved, thereby drastically decreasing the impact of electricity. Additionally, the contributions of raw materials have a larger environmental impact than those of waste disposal, indicating that it is crucial to focus on the reduction and re-usage of reactants and solvents.