JPS6328597B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for pretreating cellulosic raw materials for saccharification. When saccharifying cellulosic raw materials, pretreatment of the raw materials is necessary, and conventionally, mechanical crushing using a crusher, steaming treatment, or alkali treatment have been adopted as pretreatment methods for cellulosic raw materials for saccharification. There is. However, conventional mechanical crushing methods require a large amount of crushing power. The alkali treatment method consumes a large amount of alkali and has high saccharification properties at high temperatures (pretreatment at around 120℃).
The equipment must be pressure resistant as it is processed by
Continuous operation is difficult. Therefore, there is a disadvantage that the processing apparatus becomes large-sized. This invention was made in order to solve the disadvantages of the conventional method, and it reduces the power consumption and alkali consumption for pulverization as much as possible, and also pre-treats the cellulose raw material for saccharification continuously under normal pressure. The purpose is to This invention provides a method for pre-treating cellulosic raw materials for continuous saccharification, which combines mechanical pulverization and alkali treatment. That is, when saccharifying a cellulose-based raw material, the present invention involves pulverizing the raw material to a length of 1 to 100 mm and a diameter or width of 1 to 20 mm, and heating the pulverized raw material under normal pressure or without heating. was subjected to alkali treatment by contacting it with an aqueous solution of one selected from aqueous solutions of hydroxides, sulfides, carbonates, or sulfites of alkali metals or alkaline earth metals or a mixture of two or more of them at a concentration of 1MOL or less. This is a pretreatment method for cellulosic raw materials for saccharification, in which a post-dealkalization treatment is performed and the dealkalized raw materials are wet-pulverized. The method of this invention achieves an improved pretreatment effect by combining mechanical pulverization treatment and alkali treatment, and the drying step is omitted since the alkali treatment is followed by wet pulverization. Due to the reduction in silica, lignin, etc., the power consumption per unit weight of pulverized material can be significantly reduced. Moreover, since there is a weight loss of the solid phase (due to the removal of lignin, ash, etc.) due to the alkali treatment, the total power consumption required for pulverization can be further reduced considerably, and the saccharification residue can also be significantly reduced. Furthermore, in the method of the present invention, a cutter and/or a coarse pulverizer can be used in an appropriate combination depending on the type of cellulose-based raw material for saccharification, and the alkali treatment and dealkalization treatment can be carried out at temperatures below 100°C.
That is, since the process can be carried out under normal pressure, there is no need to consider the pressure resistance of the processing equipment, and continuous operation can be achieved using a solid-liquid countercurrent contact equipment. Therefore, it was possible to reduce the amount of alkali consumption and downsize the apparatus, and it was possible to achieve high saccharification of cellulosic raw materials. Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a process diagram of the present invention, and the pretreatment of the cellulosic raw material for saccharification consists of cutting and/or coarse pulverization, alkali treatment, dealkalization treatment, and fine pulverization steps. FIG. 2 is a schematic diagram of the invention. The cellulose raw material for saccharification 1 is cut and/or coarsely crushed into pieces having a length of 1 to 100 mm and a diameter or width of 1 to 20 mm using a cutter 2 and/or a coarse crusher 3. This cutting and/or coarse pulverization step is carried out under dry conditions in order to efficiently carry out the alkali treatment in the next alkali treatment step. The coarsely pulverized raw material passes through a hopper 4, passes through a vibrating feeder 5, is weighed by a weighing machine 6, and is conveyed to a solid-liquid countercurrent contact device 8 by a belt conveyor 7. The solid-liquid countercurrent contact device 8 has the functions of alkali treatment and dealkalization processing, and the coarsely pulverized raw material is concentrated in the stage before the solid-liquid countercurrent contact device 8.
It is continuously brought into contact with an aqueous solution of 1MOL or less for alkali treatment, and then, at a subsequent stage of the solid-liquid countercurrent contact device 8, it is continuously dealkalized by a water washing means. The dealkalized raw material is processed by Hopper 9.
The raw material is fed into the pulverizer 10 through the pulverizer 10, and is pulverized under a wet process. Wet pulverization consumes less power than dry pulverization. Next, the present invention will be explained in more detail using examples. Example 1 Using rice straw with the composition shown in Table 1 as a raw material, the first
Preprocessing was performed according to the flow shown in the figure. At this time, a 0.25 MOL NaOH aqueous solution was used as the alkaline solution, and the alkali treatment and dealkalization treatment were performed using a solid-liquid countercurrent contact device at 80° C. for a residence time of 1 hour. As a result of this alkali treatment, the rice straw composition changed as shown in Table 2. Comparing with Table 1,
Although there was almost no change in the amount of cellulose, the change in total weight was large, making it clear that pulverization after alkali treatment was more advantageous in terms of pulverization energy. Table 1 Component composition ratio (%) of raw rice straw Cellulose 40 Hemicellulose 25 Lignin 20 Ash 15 Weight 100 Table 2 Component composition ratio (%) of rice straw after alkali treatment Cellulose 38 Hemicellulose 11 Lignin 6 Ash 3 Weight 58 Table 3 shows the effect of pretreatment on the saccharification reaction. For the saccharification reaction, 0.2% Cellulase Onozuka R-10, 1.0% rice straw, temperature 40℃, pH 5.0
It was conducted under the following conditions. Table 3 shows the sugar (glucose) conversion rate 48 hours after the start of the reaction. As shown in Table 3, the process of alkali treatment→fine pulverization showed a superior pretreatment effect compared to the process of pulverization→alkali treatment. Furthermore, as shown in Table 4, from the perspective of the power consumption per unit weight of the pulverized material, the alkali treatment→
It became clear that the process of pulverization was far more effective. In addition, when pulverizing after alkali treatment, it has become clear that wet pulverization is superior to dry pulverization because there is no need for a drying process and there is no scorching caused by frictional heat generation. Table 3 Pretreatment effect on saccharification reaction Sugar conversion rate (%) Fine grinding → Alkali treatment 91 Alkali treatment → Fine grinding 86 Coarse grinding only 45 Table 4 Pretreatment effect on grinding power consumption Grinding power consumption (K WH/ Kg Rice straw pulverization → Alkali treatment 0.24 Alkali treatment → Fine pulverization 0.04 Example 2 Pretreatment was performed according to the same flow as Example 1. However, alkali treatment was performed in a flask by batch method, and the treatment temperature was 25 , 40, 80, and 120°C for treatment times of 0, 5, 1, and 3 hours.As a result of performing the saccharification reaction under the same conditions as in Example 1, the saccharification conversion rate after 48 hours was The results are as shown in Table 5. From Table 5, it is clear that treatment at temperatures below 100℃ has the same effect as treatment at 120℃.
It was found that alkaline treatment under normal pressure was sufficient. That is, not only is the pressure resistance of the alkali treatment equipment no longer necessary, but also the continuous alkali treatment has become easier.

[Table] Example 3 Pretreatment was performed according to the same flow as in Example 1. However, in order to compare the effects of the alkali treatment equipment, a diffuse user roto cell extractor and a vertical basket type extractor were used as the alkali treatment equipment. As a result, no significant difference in the saccharification reaction was found. Example 4 Pretreatment was performed according to the same flow as in Example 1. However, the type and concentration of alkali were changed as shown in Table 6. Table 6 summarizes the differences in pretreatment effects on the saccharification reaction. The sugar conversion rate is 48 hours after the start of the reaction. Table 6 Effect of type and concentration of alkali on saccharification reaction

[Table] Example 5 Pretreatment was performed according to the same flow as in Example 1 using rice hulls and sugarcane bagasse as raw materials instead of rice straw. As a result, the pretreatment effects on the saccharification reaction were as shown in Table 7. Sugar conversion rate is 48
This is after hours.

【table】 [Brief explanation of the drawing]

FIG. 1 is a process diagram of this invention, and FIG. 2 is an embodiment of this invention. 1... Raw material, 2... Cutter, 3... Coarse crusher, 4... Hopper, 5... Vibration feeder, 6
... Weighing machine, 7 ... Belt conveyor, 8 ... Solid-liquid countercurrent contact device, 9 ... Hopper, 10 ... Fine grinder.

Claims (1)

[Claims] 1. When saccharifying a cellulosic raw material, the raw material is pulverized to a length of 1 to 100 mm and a diameter or width of 1 to 20 mm, and the pulverized raw material is heated or warmed under normal pressure. The alkaline solution is made by contacting with an aqueous solution of one selected from aqueous solutions of hydroxides, sulfides, carbonates, or sulfites of alkali metals or alkaline earth metals or a mixed solution of two or more of them with a concentration of 1MOL or less. 1. A pretreatment method for a cellulose-based raw material for saccharification, which comprises subjecting the treated raw material to a dealkalization treatment, and then wet-pulverizing the dealkalized raw material. 2. The pretreatment method according to claim 1, wherein the alkali treatment and dealkalization treatment are performed in a solid-liquid countercurrent contact device. 3. The pretreatment method according to claim 1, wherein the wet pulverization is performed in a pulverizer such as a colloid mill, a refiner, a ball mill, or a rod mill.