GB283851A - Method of producing cellulosic material - Google Patents

Abstract

283,851. Euromerican Cellulose Products Corporation, (Assignees of Dorner, B.). Jan. 17, 1927, [Convention date]. Gums, carbohydrate &c.-In the preparation of paper pulp from corn stalks, straw, flax, esparto grass, and the like, and the recovery of non-cellulosic components in a utilizable form, the material is finely shredded, and the water solubleconstituents, largely saccharides, other sugars and salts, are removed by leaching in a stream of hot or cold water. Counter current treatment may be used, the process taking four or five days. The liquor may be evaporated to a syrup and used as an addition to stock food, or it may be fermented to produce alcohol. The leached material is then disintegrated in a beater, then boiled with caustic soda liquor at ordinary or increased pressures, just enough alkali being used to react with the silica present. This cooking may be done in the beater. The material is separated from this liquor and washed. The liquor containing sodium silicate and a small amount of pentosans may be treated with acid to precipitate the pentosans which may be separated and used as such, or added to the leach liquor from the first stage. The partially cooked material is then placed in an ordinary digester and cooked with caustic soda in the ordinary manner, the temperaure and pressure being such as to avoid caramelization of the pentosans. After this cooking, the liquor is drawn off and the pulp washed and bleached in the usual manner. The waste liquor from the cooking, containing large amounts of pentosans loosely combined and certain amounts of sodium carbonate and other products, is preferably treated with carbon dioxide, or it may be with sulphur dioxide, by which the pentosans are precipitated. The pentosans may be separated and used as before mentioned.