The invention relates to a process for the acylation of a solid material, known as the hydroxylated material, bearing hydroxyl groups (OH), known as reaction-generating hydroxyls, which are accessible and capable of reacting with at least one fatty acid chloride in gaseous form, said hydroxylated material being scrolled through a chamber, known as the acylation chamber, delimiting an internal space under a gaseous atmosphere. The invention also relates to an acylation device for performing said process.