Disclosed is the integration of the production of acetic anhydride from ketene, and the acetylation of wood using acetylation fluid comprising acetic acid and acetic anhydride. The invention involves recirculating acetylation fluid recovered from wood acetylation to a unit for the production of acetic anhydride from acetic acid and ketene. The acetic anhydride product stream can, in turn, be directly used as a wood acetylation fluid.

A delignified wood material is formed by removing substantially all of the lignin from natural wood. The resulting delignified wood retains cellulose-based lumina of the natural wood, with nanofibers of the cellulose microfibrils being substantially aligned along a common direction. The unique microstructure and composition of the delignified wood can provide advantageous thermal insulation and mechanical properties, among other advantages described herein. The thermal and mechanical properties of the delignified wood material can be tailored by pressing or densifying the delignified wood, with increased densification yielding improved strength and thermal conductivity. The chemical composition of the delignified wood also offers unique optical properties that enable passive cooling under solar illumination.

Disclosed is a process for the acetylation of wood, wherein the wood is impregnated with acetylation fluid and heated in stages. It is thereby secured that an acetylation reaction is conducted at a temperature above the boiling temperature of the acetylation fluid, at a stage where the impregnated wood is largely devoid of free acetylation fluid (i.e., acetylation fluid not retained in the wood matrix or in capillaries). Preferably, the process is conducted in a plant having conveyors, such as transportation screws, in the zones in which the separate heating steps are conducted.

The invention concerns a process for treating lignocellulosic material, preferably wood, comprising the following successive steps: (1) extracting lignin by a fluid in supercritical or subcritical phase to extract 40 to 85% by weight % of the lignin of the initial material; (2) filling by a filling compound, preferably in the presence of a fluid in supercritical or subcritical phase; and (3) finishing, so as to obtain a composite material formed by a three-dimensional network of filling compound that is transformed and incorporated in a network of cellulose and lignin.

The disclosure relates to a method for continuous acetylation of wood elements. The acetylation is conducted with an acetylation medium at a pressure of at least 1.5 barg in a substantially oxygen free environment. Alternatively, the method includes the steps of: (a) feeding wood elements in a substantially oxygen free environment to a continuous acetylation reactor, and (b) treating the wood elements with an acetylation medium in the continuous acetylation reactor under wood acetylation reaction conditions, at a pressure of at least 1.5 barg. The process can acetylate wood elements to a high acetyl content in an efficient way, without compromising on the quality of the material. The acetylated wood elements can be used in the production of medium density fibreboards with superior qualities such as dimensional stability and durability.

Disclosed is the integration of the production of acetic anhydride from ketene, and the acetylation of wood using acetylation fluid comprising acetic acid and acetic anhydride. The invention involves directly using raw acetic anhydride as obtained in the production thereof from ketene, as a wood acetylation fluid.

The present invention relates to an outdoor bamboo floor and a manufacturing method thereof, in particular, to an outdoor bamboo floor subjected to an immersion treatment using hot oil. Conduits or other capillary structures of a bamboo material in the outdoor bamboo floor of the present invention are filled with an oil medium, with an oil content of 2-10%. The manufacturing method includes immersing a plate blank of the bamboo floor in a hydrophobic organic medium at 100-300 C. for 1-10h, and are statically cooled down to a room temperature after being taken out.

A flame retardant treatment of a lignocellulosic material, which includes: optionally steam exploding the lignocellulosic material, impregnating the optionally steam-exploded lignocellulosic material, in or with an aqueous solution, from 0.5% to 10% of phytic acid and from 1% to 30% of urea, based on the total weight of the aqueous solution, optionally drying of the impregnated lignocellulosic material, until the impregnated lignocellulosic material has a moisture content from 5% to 20% by weight, cooking the impregnated and optionally dried lignocellulosic material, the resulting flame-retarded lignocellulosic material including a phosphorous content originating from the phytic acid from 0.1% to 10% by weight. Also, the resulting flame-retarded lignocellulosic material and the use thereof for manufacturing flame-retarded composite materials based on plant fibres, woven or nonwoven flame-retarded flexible materials based on plant fibres, and particularly textiles, flame-retarded materials based on wood fibres and/or on wood particles, and particularly flame-retarded wood panels.

A delignified wood material is formed by removing substantially all of the lignin from natural wood. The resulting delignified wood retains cellulose-based lumina of the natural wood, with nanofibers of the cellulose microfibrils being substantially aligned along a common direction. The unique microstructure and composition of the delignified wood can provide advantageous thermal insulation and mechanical properties, among other advantages described herein. The thermal and mechanical properties of the delignified wood material can be tailored by pressing or densifying the delignified wood, with increased densification yielding improved strength and thermal conductivity. The chemical composition of the delignified wood also offers unique optical properties that enable passive cooling under solar illumination.

A process for the production of acetylated wood elements, a cooling system and a wood acetylation plant are described. A process for the production of acetylated wood elements comprises acetylating wood elements and cooling the acetylated wood elements wherein the cooling comprises supplying liquid water to the acetylated wood elements to provide wetted wood elements and exposing the wetted wood elements to a gas flow.