US 12,281,183 B2
Methods for extracting xylose liquid and cellulose with high purity from corn straw
Mian Li, Quzhou (CN); Changhui Hu, Quzhou (CN); Liangcong Yan, Quzhou (CN); Jiaxing Luo, Quzhou (CN); Wulong Yang, Quzhou (CN); Weidong Xu, Quzhou (CN); and Qiang Wu, Quzhou (CN)
Assigned to ZHEJIANG HUAKANG PHARMACEUTICAL CO., LTD., Quzhou (CN)
Filed by ZHEJIANG HUAKANG PHARMACEUTICAL CO., LTD., Zhejiang (CN)
Filed on Apr. 30, 2024, as Appl. No. 18/651,620.
Application 18/651,620 is a continuation in part of application No. PCT/CN2023/096365, filed on May 25, 2023.
Claims priority of application No. 202211575495.1 (CN), filed on Dec. 8, 2022.
Prior Publication US 2024/0301094 A1, Sep. 12, 2024
Int. Cl. C08B 37/14 (2006.01); C08L 1/02 (2006.01)
CPC C08B 37/143 (2013.01) [C08L 1/02 (2013.01)] 5 Claims
 
1. A method for extracting xylose liquid and cellulose with high purity from corn straw, comprising:
step 1, raw material screening including: selecting the corn straw with a moisture content of 7%-13%;
step 2, raw material preprocessing including: processing the corn straw into powder using a pulverizer, a particle size of the powder being between 60 mesh and 300 mesh, and then putting the powder into a blower drying box and drying at 45° C. for 22 h-26 h to obtain absolutely dry powdered corn straw;
step 3, alkali processing including: after mixing the absolutely dry powdered corn straw with process water, adding 30% concentrated alkali liquid and adjusting a concentration of NaOH in the system to 0.1%-0.4%, performing the alkali processing for 1.2 h-2.0 h under a temperature of 85° C.-125° C., then obtaining straw residue and a centrifugal clear liquid by centrifugal separation, wherein the straw residue enters a xylose extraction process;
step 4, acid hydrolysis including: mixing the straw residue with a 1.0%-2.5% dilute H2SO4 solution in a certain proportion, performing the acid hydrolysis at 100° C.-160° C. for 30 min-120 min, and then performing a centrifugation to obtain an acid hydrolyzed liquid and acid hydrolyzed straw residue, wherein the acid hydrolyzed liquid is a high-purity xylose liquid, and the acid hydrolyzed straw residue enters a following cellulose extraction process;
step 5, gradient alkali processing including: after mixing the hydrolyzed straw residue and the process water, adding 30% concentrated alkali liquid and adjusting a concentration of NaOH in the system to 0.2%-1%, performing preprocessing continuously for 4.0 h-7.0 h, wherein an initial temperature is 60° C.-90° C., then for every 1 hour, increasing the concentration of NaOH by 0.1%-0.5% and increasing the temperature by 10° C.-20° C., after separating the treated material by centrifugation, washing a solid portion to obtain a high cellulose content product.