Patent ID: 8512815

Claim:
A process for the acetylation of wood comprising the steps: (a) in a reaction pressure vessel submerging wood having a moisture content of 6% to 20% by weight in an acetylation fluid at a temperature of 10° C. to 120° (b) increasing the pressure in the vessel to 2 to 20 bar for a period of 10 minutes to 300 minutes (c) removing excess acetylation fluid from the vessel by pressurizing with nitrogen gas (d) introducing into the vessel an inert fluid, circulating and heating the fluid until the internal temperature of the wood begins to show an exotherm, controlling the supply of heat to the wood until the exotherm is complete and maintaining the internal temperature of the wood below 170° C. (e) heating the circulating fluid to a temperature of 85° C. to 150° C. for a time of 10 to 30 minutes to initiate a second exothermic reaction, controlling the supply of heat to the wood until the exotherm is complete and maintaining the internal temperature of the wood below 170° C. (f) removing the circulating fluid and allowing the acetylated wood to cool to ambient temperature.