Effect of Pretreatments on the Enzymatic Hydrolysis of High-Yield Bamboo Chemo-Mechanical Pulp by Changing the Surface Lignin Content.

Lianxin Luo,Xuchong Wang,Xiaojun Yuan,Mingfu Li,Shuangfei Wang,Sheng Zhang

doi:10.3390/polym13050787

Abstract

Hydrogen peroxide chemo-mechanical pulp (APMP), sulfonated chemo-mechanical pulp (SCMP), and chemical thermomechanical pulp (CTMP) were used as raw materials to explore the effects of hydrogen peroxide (HP), Fenton pretreatment (FP), and ethanol pretreatment (EP) on the enzymatic hydrolysis of high-yield bamboo mechanical pulp (HBMP). The surface lignin distribution and contents of different HBMPs were determined using confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The correlation between the surface lignin and the enzymatic hydrolysis of HBMP was also investigated. The residue of enzymatic hydrolysis was used to adsorb methylene blue (MB). The results showed that the cracks and fine fibers on the surface of APMP, SCMP, and CTMP increased after FP, when compared to HP and EP. The total removal content of hemicellulose and lignin in SCMP after FP was higher than with HP and EP. Compared to SCMP, the crystallinity increased by 15.4%, and the surface lignin content of Fenton-pretreated SCMP decreased by 11.7%. The enzymatic hydrolysis efficiency of HBMP after FP was higher than with HP and EP. The highest enzymatic hydrolysis of Fenton-pretreated SCMP was 49.5%, which was higher than the enzymatic hydrolysis of Fenton-pretreated APMP and CTMP. The removal rate of MB reached 94.7% after the adsorption of the enzymatic hydrolysis residue of SCMP. This work provides an effective approach for a high value-added utilization of high-yield bamboo pulp.

Highlights

Non-renewable fossil energy and fuels cannot meet the development of the current social productivity with the increase in the demand for energy
Pretreatment can improve the enzymatic hydrolysis of high-yield bamboo mechanical pulp (HBMP)
The enzymatic hydrolysis efficiency of HBMP was improved by Fenton pretreatment, which was higher than with the hydrogen peroxide and ethanol pretreatments

Summary

Introduction

Non-renewable fossil energy and fuels cannot meet the development of the current social productivity with the increase in the demand for energy. As an important part of renewable energy, biomass resources can be converted into power energy after decomposition, which is of great significance for alleviating the energy crisis. Hardwood and softwood raw materials with a high cellulose content and less impurities are ideal raw materials for enzymatic hydrolysis; the life cycle is too long, and these are used as building materials to meet people’s needs, and so it limits the wood raw materials to produce biofuels, such as bioethanol. As a perennial grass, is found in East and Southeast Asia. Compared with agricultural waste, such as wheat straw and straw, bamboo has higher cellulose and hemicellulose contents

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Results

Conclusion