BIOMASS DELIGNIFICATION CHEMICAL PROCEDURE FOR OBTAINING A ROMANIAN SPRUCE WOOD-INSULATING MATERIAL

Abstract

A procedure for making a wooden heat-insulating product for construction applications through lignin removing is presented in this paper. The non-conventional procedure is almost similar to that known and used in the pulp and paper industry, but the technological purpose is clearly different. The type of tree wood chosen by authors (Romanian spruce wood) is a novelty compared to the rather large list of tree species tested so far and represents the originality of the work. The liquid alkaline environment was constituted of NaOH, Ca(OH)₂, and distilled water and this has activated the spruce wood waste. By removing lignin from the wood structure, heat conductance of the wooden material decreased by comparison with conductance of the same type of non-treated wood. The heat treatment temperature into an electric oven was 95 ℃ for 8 hours. The results showed the possibility to obtain a product with denseness value of 0.14 g·cm^-3 and heat conductance of 0.030 W·m^-1·K^-1, i.e. very good insulation properties. Analyzing the material quality, this was almost identical to high-performance wooden materials.