Characterization of Hydrolysis Lignin Bonding Properties During the Pelletization of Eucalyptus Sawdust
- Authors
- Publication Date
- Mar 01, 2020
- Source
- GuangZhou Institute of Energy Conversion
- Keywords
- License
- Unknown
- External links
Abstract
This work assessed the effects of the bonding of hydrolysis lignin during the pelletization of eucalyptus sawdust. The characteristic thermal transition temperatures of hydrolysis lignin and eucalyptus sawdust were initially determined using differential scanning calorimetry, and the glass transition temperatures (T-g) were recorded at 94.4 and 87 degrees C, respectively, while their melting temperatures were recorded at 136.5 and 127.4 degrees C, respectively. The temperature range of 80-160 degrees C is set in order to include the thermal transition temperature spans of these materials. Single pellet making experiments were conducted using a uniaxial piston-cylinder compression apparatus and acceptable pellet properties were observed when pelletizing at temperatures between the end point of the T-g region and the melting temperature and at 20-30% hydrolysis lignin content. Examinations of the internal cross-sections of these pellets by scanning electron microscopy showed that cracks between particles were filled sufficiently with hydrolysis lignin, allowing particles adhere to one another tightly after the glass transition of hydrolysis lignin. The assessment of functional group changes during the pelletization process using FTIR found that the lignin evidently improves the physical properties of the pellets by reducing the quantity of some oxygen-containing functional groups while elevating the concentrations of alcohol or phenol -OH groups, hydrocarbon or naphthene -CH bonds.