Waste wood as a source for the production of fully recyclable filters and insulation materials made from aerogels

Abstract

Waste wood as a source for the production of fully recyclable filters and insulation materials made from aerogels

Martin Sgrajaa, Steffen Sydowb, Marina Schwana, Barbara Milowa

a Institute of Materials Research, German Aerospace Center,51147 Cologne, Germany b Fraunhofer Institute for Wood Research, 38108 Braunschweig, Germany

Cellulose and lignin are among the most widespread biopolymers in the world and are found in varying proportions in all plant cells. As a source of raw materials, wood is of particular interest as it is available in large quantities in Germany and Europe and is used extensively in our daily lives. Furthermore, waste wood, which has reached the end of its life cycle and is produced in large quantities every year, is also becoming an interesting source of raw materials for the synthesis of new high-quality and sustainable products. One group of such highly functional materials are aerogels, highly porous solids with up to 99 % pore content, a precisely adjustable pore size distribution, high porosity and large inner surface areas. These properties along with a low thermal conductivity and low density offer an interesting range of applications for thermal insulation and pollutant adsorption. In the underlying project the synthesis of aerogels from cellulose and lignin and the characterization of their properties are going to be addressed. In addition, the materials produced will be tested in two different applications. In the first case, wood fibre insulation panels are considered in which the thermal conductivity is to be significantly improved by adding aerogel particles. In the second case, the aerogels will be transformed into carbon aerogels and their adsorption ability with respect to harmful gases will be examined. Furthermore, the recycling of the aerogel containing insulation panels as well as of the carbon aerogel filters will also be considered in the project. Initial results on the synthesis of the aerogels, their properties and the characteristics of the filters and insulation boards produced from them are going to be shown. The densities as well as the specific surface areas, obtained from physisorption, for the cellulose, lignin and carbon aerogels will be presented. In addition, initial results concerning the thermal conductivity of the aerogel wood fibre insulation boards and an initial characterisation of a carbon aerogel filter will be shown. This work was performed within the project AltHolzAerogel (funding number 2221HV038B) and is supported by the Federal Ministry of Food and Agriculture.