Breakthroughs in cost-effective, scalable production of superinsulating, ambient-dried silica aerogel and silica-biopolymer hybrid aerogels: from laboratory to pilot scale

Silica aerogel superinsulation products have a tremendous growth potential, particularly for industrial and pipe insulation. However, the high production cost and the poor mechanical properties prevent the adoption of silica aerogel superinsulation outside of the established niche markets. In this paper, we address these two barriers. We analyze the solvent use of current production processes for ambient-dried silica aerogel and derive a minimal solvent process that approaches the theoretical minimum of one volume of solvent for one volume of aerogel. We apply this process at the pilot scale and produce aerogel granulate with a thermal conductivity of 17.4 mW/(m·K). A review of the different mechanical reinforcement strategies reveals that strengthening typically comes with a penalty in thermal conductivity. In contrast, we highlight some of our recent work on hybrid polysaccharide (cellulose, pectin)—silica aerogels, where the mechanical reinforcement did not significantly increase thermal conductivity as a promising avenue for more robust silica-based hybrid aerogel materials.