Economic assessment of the production of subcritically dried silica-based aerogels

Traditionally, most commercial aerogels are produced by supercritical drying methods which make their application undesirable, more expensive, and less energy efficient. This paper presents the economic assessment of silica-based aerogels synthesized via ambient pressure drying. Three different approaches were considered in this paper: the production of inorganic aerogel and of two hybrid aerogels. The synthesized aerogels will be incorporated as aggregates in wall coatings to improve their thermal performance. The application of the Life Cycle Assessment (LCA) methodology is exceedingly important since it considers all costs associated with a product, process or activity during their physical and economic life, allowing the optimization of the total costs. It was possible to evaluate the production stages of the subcritical silica aerogels that influence their final cost and their relative contribution. These results allow to identify the main aspects that influence the total cost of the synthesis process. It is important to emphasize that this study is suitable for laboratory scale activities leading to high costs. It naturally follows that an adjustment to industrial scale applications is of paramount importance and should be made to maximise the economies of scale and to achieve additional gains in efficiency.