Straw pretreatment method for extracting hemicellulose

[0020] Add 100kg of bagasse to the extraction tank. After the extraction tank is evacuated, inhale 1000L of pretreatment solution (aqueous sodium hydroxide solution with a concentration of 5g / L) at a solid-to-liquid ratio of 1g: 10mL, and soak for 10 hours at room temperature. Then discharge 330L of free lye in the bagasse, and the discharged solution is dark brown. The remaining material in the extraction tank is sent to a high-concentration disc-type paper refiner, and the material is ground into filaments with a diameter of 0.1-0.5mm. Centrifuge the material obtained from the pulp, discharge the free lye in the ground fiber, collect 550L of liquid, add 300L of water to the bagasse, stir and wash, then centrifuge again to discharge 295L of alkali-containing washing water, and combine three times of liquid to obtain 1175L, in which no xylan was detected ; Collect the solid, which is the treated bagasse fiber, and the obtained bagasse fiber is soft and dense.

[0024] Weigh 50 kg of bagasse fibers treated by the method described in Example 1 and 50 kg of hemicelluloses treated by the method described in Comparative Example 1 and extract hemicellulose by alkaline method respectively.

[0025] The extraction conditions are: solid-to-liquid ratio 1g:5mL, lye used for extraction is NaOH aqueous solution with a concentration of 8% (w / v), extraction time is 12h, and temperature is room temperature.

[0026] Then carry out NaOH concentration, color and luster contrast to the obtained hemicellulose extraction solution, and with 95% (v / v) ethanol alcohol precipitation that is equivalent to 3 times of extraction solution volume, 75% ethanol washes hemicellulose, finally to dry hemicellulose The color, purity and extraction rate of the plain powder were compared, and the results are shown in Table 1.

[0027] Table 1:

[0028]

[0029] As can be seen from Table 1, when the bagasse treated by the method of the present invention is extracted

[0031]Cut corn stalks into small sections with a length of 1 to 3 cm, weigh 100 kg and put them into an extraction tank, add 1000 L of pretreatment liquid (concentration is 5 g / L sodium hydroxide aqueous solution) at a ratio of 1 g to 10 mL, and heat up to Soak for 1 hour at 60°C. Afterwards, 330L of free lye in the material is discharged, and the solution is dark brown. Then, the remaining material in the extraction tank is sent to a high-concentration disc-type paper refiner, and the material is ground into filaments with a diameter of 0.1-0.5mm. Centrifuge the material obtained from the slurry, discharge the free lye in the ground fiber, collect 560L of liquid, add 300L of water to the bagasse, stir, mix and wash, then centrifuge again to discharge 298L of alkali-containing washing water, and combine three times of liquid to obtain 1188L, in which no xylan was detected ; The collected solid is the processed corn stalk fiber, and the obtained corn stalk fiber is soft and dens