ABSTRACT
In previous sections, it was pointed out that high temperature steam, i.e., both a high humidity and a high temperature, may chemically degrade wood constituents. In this section, the degradation of wet wood components at a temperature up to 200 °C is discussed. Hemicelluloses contain many carboxyl groups, rendering wood a naturally acid material. the reactivity of the wood components under acid conditions is special. Indeed, the components that can be hydrolyzed participate in the acidification of the medium. the acid medium can differ significantly according to the conditions under which the tHM treatment is carried out. the temperature, the moisture content distribution, the time of treatment and the pressure can strongly affect the reactivity of the medium.
