METHOD FOR DELIGNIFYING LIGNOCELLULOSIC RAW MATERIALS

摘要

The invention relates to a method for delignifying lignocellulosic raw materials by using sulfites in the presence of an alkaline component, especially sodium hydroxide or sodium carbonate or a mixture thereof in an aqueous solution at a high temperature and high pressure. The invention is characterized in that a first partial fragment of the alkaline component is added when the aqueous solution starts to decompose and in that at least a second partial fragment of the alkaline component is added only when delignification begins.