Study calls for aerogels to diversify
A market study calls for the aerogel industry to broaden its reach beyond applications in oil and gas. Simon Frost reports.
When a chart showing the stock price of aerogel industry leader Aspen Aerogels, USA, is plotted over a chart of global crude oil performance, their parallel trajectories are made clear. A new study by Dr Richard Collins, a technology analyst for IDTechEx, UK, examines this link and calls for the aerogel industry to diversify its applications to end its reliance on oil and gas.
‘The combination of aerogel properties lends itself very nicely to oil and gas requirements, such as thermal insulation, hydrophobicity and flame retardance,’ Collins told Materials World. ‘Alongside this, associated benefits such as speed of installation and the amount that can be transported also play a key role – but aerogels remain expensive, which has limited uptake elsewhere.’
Silica aerogel composite blankets and panels – formed in a gelation process with silica aerogel and, typically, glass fibre or polyethylene – are the dominant aerogel products, used extensively for insulation in oil refineries and subsea pipelines. ‘Silica aerogel is a fantastic insulator as a result of the Knudsen effect,’ Collins explained. ‘The pore size is approximately 20nm, which is smaller than the mean free path of air (70nm), and this all but eliminates the available thermal convection.’
But while oil and gas has been instrumental in bringing aerogels into commercial use, the lack of significant uptake by other industries leaves aerogel producers at the mercy of a volatile global oil market. Aspen Aerogels reported a revenue decrease of almost US$10m in the first quarter of 2017, citing lower activity levels in the subsea market, and delayed building of its second manufacturing plant in 2016.
In the report, Aerogels 2017-2027: Technologies, Markets and Players, Collins outlines a strategy for the industry, earmarking industrial insulation and building and construction insulation as recommended areas for significant growth in the next ten years, with further increases coming from less well explored areas such as electrical systems, filtration, aerospace, packaging, cosmetics and clothing. ‘The rapid growth is expected to be in both building and construction and district energy. These areas will be assisted by greater exposure, cost reductions and legislative drivers,’ he said.
Collins notes that the cost of producing silica aerogels – which can only be used commercially in a composite due to their brittleness – must be reduced. ‘This cost reduction will come either through scale and the associated infrastructure or through manufacturing advancements,’ he said. ‘The main manufacturing challenge for an aerogel is the removal of the solvent from a sol-gel without the pores collapsing. This is classically done under supercritical fluid conditions. Advancements could come from proposed projects in either supercritical drying or alternative ambient pressure drying processes.’
While silica aerogels can come in many forms, other types of aerogel are beginning to gain commercial interest. ‘The most notable of these are polymer aerogels, which are starting to reach the stage of early commercial sales,’ Collins said.
‘Polymer aerogels are very diverse, depending on their chemical makeup, but one of the immediate advantages is that the majority are no longer brittle and they have a high compressive and tensile strength. The properties and manufacturing processes are similarly diverse for these products,’ he added.
Chemists at Missouri University of Science and Technology, USA, for example, reported in May 2017 that they had developed polymeric aerogels with shape-memory capabilities. ‘The specific kind of polyurethane aerogels we have created are superelastic, meaning that they can be bent in any direction or be smashed flat and still return to their original shape,’ said lead researcher Dr Nicholas Leventis.
Graphene aerogels, meanwhile, are gaining traction as electromagnetic absorbers for use in applications such as energy storage, sensors and catalysis, with desirable conductive and anticorrosive properties.
‘Aerogels are a specific class of porous materials with huge potential. They are still often viewed as “space-age” technology, but the reality is that commercial ventures are a lot closer to home – and, in some cases, inside the home,’ Collins said.
To view an abstract of the report, visit bit.ly/2vS8YUf