Comparative Study on Pretreatment Processes for Different Utilization Purposes of Switchgrass
Fan Wang1,2, Dongxiang Shi1,3, Ju Han1,2
1Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao, Shandong 266101, China.
ACS Omega
|September 14, 2020
Summary
Switchgrass pretreatment using sodium hydroxide, nitric acid, or ethanol organosolv offers pathways for biofuels, nanocellulose, and papermaking. Nitric acid pretreatment is optimal for nanocellulose production.
Area of Science:
- Biomass Conversion
- Plant Science
- Chemical Engineering
Background:
- Switchgrass (Panicum virgatum) is a high-yield biomass crop suitable for low-input cultivation.
- Its potential for biofuels, papermaking, and nanocellulose production is significant.
- Optimizing pretreatment methods is crucial for efficient utilization of switchgrass.
Purpose of the Study:
- To compare 12 chemical pretreatment methods for switchgrass utilization.
- To identify optimal pretreatments for biofuel (fermentation), nanocellulose, and papermaking applications.
- To characterize the structural and chemical changes in pretreated switchgrass.
Main Methods:
- Laboratory-scale chemical pretreatments including sodium hydroxide, nitric acid, and ethanol organosolv.
- Analysis of residual lignin, cellulose, and hemicellulose content.
- Characterization using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR).
Main Results:
- Sodium hydroxide pretreatment yielded mixed sugars for fermentation with 11.10% residual lignin and 53.85% residual cellulose.
- Nitric acid (2.00%, 125 °C, 30 min) effectively removed 78.37% hemicellulose and 39.82% lignin, suitable for nanocellulose.
- Ethanol organosolv delignification resulted in 58.56% residual cellulose for papermaking.
Conclusions:
- Different chemical pretreatments are effective for specific switchgrass applications.
- Nitric acid and ethanol organosolv pretreatments show promise for nanocellulose and papermaking, respectively.
- Characterization techniques confirmed structural and chemical modifications crucial for material properties.
