Chemical Method of Biomass Delignification as An Advanced Technique for Preparing Wood Foam with Insulating Properties

The paper refers to a method of lignin removing in the biomass structure to obtain a wooden material with excellent heat-insulating properties suitable for use as an insulating material in construction. In principle, the method is almost similar to that applied in the pulp and paper industry, but with a different technological purpose. The chemical activation of maple wood waste was obtained through contact with an aqueous alkaline environment containing NaOH and Ca(OH)2 the effect being significant reduction of thermal conductivity compared to non-chemically treated wood. The originality is the use for the first time of maple wood as recycled sawdust. The process temperature was 90℃ for 8 hours. Results were remarkable, the optimal product having density of 0.21 g·cm-3 and heat conductivity of 0.029 W·m-1·K-1. In quality terms, the delignified wood features were almost similar with other foamed wooden products.