Method for Thermal Drying of Wood in a CO2 Atmosphere, Drying Facility for Implementing Said Method, and Product Obtained

A method of thermally drying wood using a drying plant comprising at least one drying chamber, said method comprising the following steps:

• injecting a coolant gas comprising CO2 at a selected pressure and temperature into the drying chamber;
• force the circulation of the coolant gas through the drying chamber;
• heating the coolant gas circulating in the drying chamber according to a first phase bringing the average temperature of the drying chamber from the ambient temperature to 80° C. according to a selected temperature gradient in order to extract the free water from the wood to be dried, then a second phase from 80° C. to 140° C. according to the specific drying profile of the wood to be dried, which comprises a specific temperature increase profile and allows the extraction of the bound water specific to the wood to be dried;
• extracting the binary gas mixture comprising CO2 and water from the drying chamber in the form of steam at high temperature and discharging the water thus extracted from the wood load from the chamber;
• controlling the injection, circulation, reheating and evacuation stages according to programs, set values and appropriate drying times according to the specific hygrometric evolution curve in the heart of the wood depending on the drying time and the temperature increase sequencing specific to the type of wood to be dried;
• and collecting all the data formed by the variations in physical metrological measurements, comparing them with the set values dictated by the specific profile of the wood to be dried, and readjusting the operation of the drying plant in the event of deviation from the set values.