Porous Glass for Thermal Insulation in Buildings with a Focus on Sustainable Materials and Technologies: Overview and Challenges

In response to environmental challenges and primary resource scarcity, sustainable approaches that rely on recycling and reusing waste materials are becoming valuable and highly appealing options in modern society. This paper deals with the usage of porous glass and glass-ceramic products derived from waste in the field of thermal insulation in buildings. After providing an overview of the current state of the art with a focus on existing commercial products and related manufacturing methods (foaming strategies), this review discusses the emerging trends toward greener approaches, including the use of by-products or waste substances as foaming agents (e.g., eggshells or mining residues), the use of vitrified bottom or fly ashes from municipal solid waste incinerators as starting materials, the application of surface treatment to reduce post-processing temperatures, and the promise of additive manufacturing technologies in this field. The increased use and spread of sustainable practices are expected to significantly contribute to glass recycling, to minimize landfilling, and to generally reduce energy consumption as well as greenhouse emissions.