| 摘要 |
The increase of the feed value of lignocellulosic materials is achieved by treatment with an alkaline liquid and subsequent neutralisation using an acidic liquid in a closed system with circulation of the treatment liquids. The process liquids, during the course of the treatment, are fed at a rate corresponding essentially to the liquid absorption of the lignocellulosic material, as a result of which the amount of residue solutions obtained from the treatment are kept to a minimum. The alkaline and acidic liquids are fed in this case in the form of concentrates, while the water provided for dilution is fed separately at a rate corresponding to the liquid absorption of the lignocellulosic material. The process is carried out by using an apparatus having a distribution part (24) which is mounted on the top part of the vessel (10) and is suitable for feeding alkaline and acidic liquids and has an outlet for liquids, which exit from the lignocellulosic material, which outlet is mounted on the bottom part of the vessel. The apparatus also contains a pump collecting receiver (12), which is connected to the outlet, liquids and, possibly, likewise separately, water being fed to the receiver. The operating liquid is re-applied via a circulation pump (18) and a charging line (22). <IMAGE> |
