Abstract
This study performed microwave-assisted acid pretreatment on pure lignin. The effects of microwave temperature, microwave time, and hydrochloric acid concentration on characteristics and pyrolysis behavior of lignin were examined. Results of ultimate analysis revealed better properties of all pretreated samples than those of raw lignin. Fourier transform infrared spectroscopy analysis showed breakage of β–O–4 bond and aliphatic side chain, decrease in –OH groups, and formation of C[dbnd]O groups in pretreatment. Microwave temperature exerted more significant influence on lignin structure. Thermal stability of treated lignin was improved and insensitive to short microwave time and acid concentration under mild conditions. Resulting from improved alkyl-phenols and decreased alkoxy-phenols, microwave-assisted acid pretreatment of lignin yielded bio-oil with excellent quality. Total yield of phenols in pyrolysis vapors (200 °C) improved to 14.15%, whereas that of guaiacols decreased to 22.36%. This study shows that microwave-assisted acid pretreatment is a promising technology for lignin conversion.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 57-62 |
| Number of pages | 6 |
| Journal | Bioresource Technology |
| Volume | 251 |
| DOIs | |
| State | Published - Mar 2018 |
Bibliographical note
Publisher Copyright:© 2017 Elsevier Ltd
Keywords
- Acid
- Characteristics
- Lignin
- Microwave
- Pretreatment
- Pyrolysis behaviors