Upscaling and cost reduction of silica aerogel production
The widespread application of silica aerogels is currently hindered by either the poor mechanical properties or high production costs of these materials. The growth potential of aerogels insulation products is in excess of 50% by volume per annum. In 2013, a one-pot production process was patented by Empa. This process minimizes the use of solvent and allows to produce silica aerogel granulate by ambient pressure drying within only 5 hours from start to finish. The production process consists of three steps: gelation, modification and ambient pressure drying. The production process was recently scaled up in a pilot reactor with a batch volume of 70 L. The aerogel granulate produced by this method has a thermal conductivity of 17.9 mW/(m.K), as low as that of commercially available granulate.