Abstract: The invention is directed to a process for the continuous acetylation of wood elements. The process particularly combines a batchwise impregnation step, with a continuous reaction step. In order to realize this, a collection step is built-in, so as to allow batches of impregnated wood elements to be fed into a reactor in a continuous manner. Very high acetylation contents can be obtained, at a level that had not been achievable before in a continuous and non-catalyzed acetylation process.

Abstract: Disclosed is a reactor system for the modification of lignocellulosic materials. According to the invention, the system comprises a reaction vessel, a vacuum connection and an inlet and/or outlet connected to a gas flow loop connected to a heat exchanger and at least one fluid circulation device. Particularly, gas flow loop is arranged so as to allow gas circulation over the diameter of the reaction vessel. The gas flow loop preferably includes a gas distribution device, such as a distribution plate.

Abstract: The present invention describes a process for the acetylation of wood comprising treating wood with an acetylation agent comprising acetic anhydride and/or acetic acid and subjecting to acetylation conditions, wherein the acetylation reaction is carried out in the presence of an acetylation catalyst comprising a salt of an organic acid, wherein the organic acid is a carboxylic acid, phenol or a substituted phenol, wherein the carboxylic acid is chosen from the list consisting of aromatic carboxylic acids, medium chain saturated monocarboxylic acids, keto acids, dicarboxylic acids, tricarboxylic acids, hydroxy acids, amino acids and derivatives thereof.

Abstract: A system for treating wood (30), comprising: —a treatment vessel (14) configured to receive at least one wood stack (4) for treatment, and —a stack holding system (2) for holding a wood stack (4), the stack holding system (2) comprising: —a frame (6), configured to support the wood stack (4); —a first element (8), connected to the frame (6) near an upper side of said frame (6), configured to exert a first, downward force on the wood stack (4); and —a second element (10), connected to the frame (6) near a lower side of said frame (6), configured to exert a second force on the wood stack (4) in a direction opposite said first force. The invention also comprises a method for treating wood, using a system for treating wood according to the invention.

Abstract: A system for treating wood (30), comprising: —a treatment vessel (14) configured to receive at least one wood stack (4) for treatment, and —a stack holding system (2) for holding a wood stack (4), the stack holding system (2) comprising: —a frame (6), configured to support the wood stack (4); —a first element (8), connected to the frame (6) near an upper side of said frame (6), configured to exert a first, downward force on the wood stack (4); and —a second element (10), connected to the frame (6) near a lower side of said frame (6), configured to exert a second force on the wood stack (4) in a direction opposite said first force. The invention also comprises a method for treating wood, using a system for treating wood according to the invention.

Abstract: The present invention describes a process for the acetylation of wood comprising treating wood with an acetylation agent comprising acetic anhydride and/or acetic acid and subjecting to acetylation conditions, wherein the acetylation reaction is carried out in the presence of an acetylation catalyst comprising a salt of an organic acid, wherein the organic acid is a carboxylic acid, phenol or a substituted phenol, wherein the carboxylic acid is chosen from the list consisting of aromatic carboxylic acids, medium chain saturated monocarboxylic acids, keto acids, dicarboxylic acids, tricarboxylic acids, hydroxy acids, amino acids and derivatives thereof.

Abstract: Disclosed is a modified refiner system for the acetylation of wood chip and/or wood fiber. The invention comprises a process for the acetylation of wood chip in a refiner system including a feed hopper component, a non-steam digester component and a refiner (defibrator) component in which the chip is contacted with an acetylating fluid between the hopper and the digester components within a connecting multi-zone compression feed screw.

Abstract: A process for the acetylation of wood comprising submerging the wood in an acetylation fluid under pressure, and subsequently heating the wood under controlled conditions to initiate two distinct exothermic reactions. The process permits the simultaneous upgrading of large quantities of commercial wood sizes having a natural durability class 4 or class 5 to a unique product of durability class 1 or class 2.

Abstract: A one or two step process for the acetylation and refining of wood pieces in which acetylation and refining to a reduced geometry take place simultaneously in the refiner. Engineered board products comprising acetylated reduced geometry materials possess high dimensional stability and durability compared to like board products comprising non-acetylated materials.

Abstract: Disclosed is a reactor system for the modification of lignocellulosic materials. According to the invention, the system comprises a reaction vessel, a vacuum connection and an inlet and/or outlet connected to a gas flow loop connected to a heat exchanger and at least one fluid circulation device. Particularly, gas flow loop is arranged so as to allow gas circulation over the diameter of the reaction vessel. The gas flow loop preferably includes a gas distribution device, such as a distribution plate.

Abstract: The invention relates to a process for acetylation of wood having a density of above 400 kg/m3, particularly, of Southern Yellow Pine, and acetylated wood obtainable by this method. The described acetylation process allows the production of acetylated wood having higher acetylation levels, such as an acetyl content of at least 20% by weight. The acetylated wood has also a low residual acetic acid content, in particular, lower than 1% by weight. The invention is particularly useful for acetylation on industrial scale of pieces of solid wood, preferably, of wood beams.

Abstract: Disclosed is acetylated wood comprising one or more end grain surfaces, wherein the wood is selected from the species Red Alder and European Alder. The acetylation of these wood species surprisingly result s in a lowering of the water absorption by immersion at an end-grain surface. Thus, acetylation can be used for the purpose of lowering the water absorption by immersion at an end-grain surface of wood selected from the group consisting of Red Alder and European Alder. The invention also pertains to wood having tangential surfaces, showing a surprising extent of aggregate rays. Further disclosed is a method of providing stable discoloured acetylated Red Alder [and European Alder], comprising a step of subjecting the acetylated wood to UV exposure.

Abstract: The invention is directed to a process for the continuous acetylation of wood elements. The process particularly combines a batchwise impregnation step, with a continuous reaction step. In order to realize this, a collection step is built-in, so as to allow batches of impregnated wood elements to be fed into a reactor in a continuous manner. Very high acetylation contents can be obtained, at a level that had not been achievable before in a continuous and non-catalyzed acetylation process.

Abstract: Disclosed is a modified refiner system for the acetylation of wood chip and/or wood fibre. The invention comprises a process for the acetylation of wood chip in a refiner system including a feed hopper component, a non-steam digester component and a refiner (defibrator) component in which the chip is contacted with an acetylating fluid between the hopper and the digester components within a connecting multi-zone compression feed screw.

Abstract: A composite wood product containing acetylated wood elements characterized by an average value in thickness swelling not exceeding 5% after subjection to 25 wet-dry/freeze-thaw cycles as described in Table II. Alternative characterizations include moduli of elasticity and rupture, and bending strength. A two stage process for the acetylation of wood elements is also described.

Abstract: A one or two step process for the acetylation and refining of wood pieces in which acetylation and refining to a reduced geometry take place simultaneously in the refiner. Engineered board products comprising acetylated reduced geometry materials possess high dimensional stability and durability compared to like board products comprising non-acetylated materials.

Abstract: A process for the acetylation of wood comprising submerging the wood in an acetylation fluid under pressure, and subsequently heating the wood under controlled conditions to initiate two distinct exothermic reactions. The process permits the simultaneous upgrading of large quantities of commercial wood sizes having a natural durability class 4 or class 5 to a unique product of durability class 1 or class 2.

Abstract: A composite wood product containing acetylated wood elements characterised by an average value in thickness swelling not exceeding 5% after subjection to 25 wet-dry/freeze-thaw cycles as described in Table II. Alternative characterisations include moduli of elasticity and rupture, and bending strength. A two stage process for the acetylation of wood elements is also described.

Abstract: The invention relates to a process for impregnating wood or wood based material. A working solution is preheated to a temperature above the atmospheric boiling point (“a super hot temperature”) above the atmospheric boiling point (“a super hot temperature”) of the working solution, at an elevated pressure sufficient to maintain the working solution in the liquid phase. The working solution is contacted with a wood or wood based material at a super hot temperature and an elevated pressure to cause impregnation of the solution into the wood or wood based material. The impregnated wood or wood based material and any remaining working solution, waste material and/or by-products are then separated.