Aerogels produced from cellulose extracted from hemp are as effective as those obtained from industrial cellulose
German and French researchers are studying new ways to extract cellulose from used hemp fibers to make aerogels, high-tech materials that have a wide range of industrial uses
While aerogels have historically been made from highly polluting inorganic materials such as silica or alumina, research aims to advance their development from more environmentally friendly organic polymers and carbon.
“This opens the door to using used hemp fibers as the main source of cellulose for these materials, which can be extracted under mild conditions, using cheap and safe reagents,” said declared Diogo Costa, a fellow of the Marie Skłodowska-Curie European Industrial Doctoral Program, who is researching this material as part of his broader study of bio-based and circular economies.
Costa's research is funded by a grant from the Biobased Value Circle (BVC), a consortium made up of four European universities, one research institute and nine European companies.
What are aerogels?
Invented in the 1930s, aerogels, whose liquid content is replaced by air, have received increasing attention over the past 20 years for their application to the electrodes of supercapacitors, ultracapacitors, batteries and desalination, as a high temperature insulation material and as a catalyst for carbon nanotubes and other materials. Strong yet porous, the material offers the key benefit of low thermal conductivity, heat transfer.
NASA uses aerogels for the insulation of launch vehicles and shuttles, life support equipment, rocket engine test beds and for the insulation of astronauts' hands and feet. Commercial applications include pipe insulation, construction, refrigeration appliances and equipment, and automobiles, as well as consumer applications, such as clothing.
Research so far has shown that aerogels made from cellulose extracted from hemp in the form of beads, sheets and cylindrical monoliths are as effective as those made from commercial industrial cellulose, according to Costa.
Cellulose, which makes up 65 to 75 percent of the biochemical makeup of hemp fibers, is of particular interest because of its abundance, biocompatibility, and because it can be obtained from waste, Costa said.
"This new set of materials will open up new growth opportunities for hemp-based businesses, and can create new and better jobs in rural communities, while delivering the well-known environmental benefits of hemp," he said. . “Aerogels will become an increasingly large and interesting market in which the hemp industry can participate, from producers who want to profit from their waste, to new sectors, new companies and investors. »
According to New York-based researcher Future Market Insights, the aerogel market is worth around $1 billion and is expected to grow 17% per year through 2030.
Dr. Costa's research, which focuses on product development and supply chain considerations, is carried out in cooperation with the Cologne-based German Aerospace Center (DLR), which develops materials for to replace current petroleum-based thermal insulators, and with the young company KEEY Airgel, located in Habsheim, France, which are both members of the BVC consortium.
Besides exploring the potential of low-grade hemp fibers from stalk processing as the basis for the new class of non-polluting, bio-based aerogels, Mr. Costa is also exploring how to scale up production and bring these products to market, which, he says, is a major challenge.
“Current methods of developing hemp cellulose-based aerogels are still time-consuming,” Costa said. “Their scaling must be optimized and many other factors must be taken into account, including resistance to humidity, microbial activity and combustion,” he added.
Lightening supply chains and reducing dependence on raw materials imported from abroad are major challenges addressed in wider European policies aimed at advancing bio-based and circular business models, the broader context of Mr. Costa's research.
With the EU designating hemp as an "essential crop" under the Union's Common Agricultural Policy (CAP), and given the ambitious environmental goals represented by the European "Green Deal", Costa's project s fits perfectly into the Union's strategy to develop these alternative economic models.
“The valorization of crops such as hemp, flax, maize and wheat, as well as their respective residues, is one of the main alternatives being researched in the EU,” said Mr Costa.
As part of the European Green Deal and the European Bioeconomy Strategy, the EU should update legislation and labels dedicated to bio-based products, and launch a circular thematic investment platform of 100 million euros, among other activities aimed at mobilizing stakeholders representing academia, industry and society, observed Mr. Costa.
In addition, the EU has invested €3,7 billion in bioeconomy research and innovation projects over the past seven years, and this investment is expected to increase to €10 billion by 2030 in the Horizon Europe, a key research and innovation funding program that aims to address climate challenges.
Companies that participate in the Biobased Value Circle consortium hire or host PhD students for long-term internships as part of a program to train a new generation of researchers to support the development of innovative biobased products that can lead to more sustainable economies. .