GB444766A - Improvements in and relating to saccharification of cellulose - Google Patents

Abstract

In a process for saccharifying cellulose by intermittently passing batches of dilute acid through it, such as described in Specification 367,916, each batch is employed at a lower temperature than that of the cellulose, the temperature of the latter being raised after each acid batch has passed through it and it may be to a temperature higher than that it possessed before the supply of the preceding batch of acid. The temperature may be raised by passing steam into the cellulose from below before or during the introduction of each batch. The acid may be forced through the cellulose by steam pressure and/or by reducing pressure below the cellulose. The concentration of the batches may increase from batch to batch and the concentration in an individual batch may be lower in the earlier portion than in the later. The successive batches may become progressively smaller to correspond with the shrinkage of the cellulose and in this event the time interval between batches may be made progressively smaller. The cellulose is preferably in short fibred form as by cutting wood across the grain into plates. To break down higher sugars such as cellobiose the extract may be after-hydrolyzed by maintaining it at a higher temperature.