procédé Natta

CONT: Le procédé Natta est un procédé continu qui utilise l'acide chlorhydrique : l'hydrolyse s'effectue avec de l'acide dilué et de la vapeur injectée vers 200 °C à la base du réacteur, cette vapeur monte à contre courant de la matière à traiter et entraîne le furfural formé. (...) L'acide acétique peut être facilement récupéré.

CONT: [The acid hydrolysis of wood]. The ""Natta process"" uses hydrochloric acid as the catalyst. The raw material used is moistened with dilute hydrochloric acid and is fed continuously into the top of a vertically arranged reactor. Superheated steam at a temperature of 190° to 200°C is injected at the bottom of the reactor, passes through the material in a countercurrent stream, and leaves the digester at the top, taking the furfural with it. The condensate contains only a small amount of hydrochloric acid and this is neutralized before the furfural is purified. The process operates continuously, uses considerably less steam and acid than the sulfuric acid process described above, and gives furfural yields of 70% to 80% of the theoretical amount. ... The process also permits the recovery of the acetic acid formed as a by-product.