Document Type
Article
Publication Date
6-3-2016
Keywords
red liquor, hydrothermal conversion, hydrochar, higher heating value, ash content, thermogravimetric analysis
Abstract
Hydrochar was produced from neutral sulfite semi-chemical (NSSC) red liquor as a possible bio-based solid fuel for use in power generation facilities. Hydrothermal conversion (HTC) experiments were conducted using a fixed liquor-to-water volume ratio of 1:8 and reaction time of 3 h. Solutions were processed using different chemical additives, pH and temperature conditions to determine the optimum conditions required for producing a high energy content solid fuel. The hydrochar samples produced were analyzed by ultimate, thermogravimetric (TGA) and Fourier transform infrared spectroscopy (FTIR) analyses to determine physicochemical properties that are important for utilization as a fuel. The residual process liquids were also analyzed to better understand the effect of HTC process conditions on their properties. It was determined that the optimum conditions for producing a solid fuel was at a reaction temperature of 250 C, in the presence of acetic acid at pH 3. The maximum energy content (HHV) of the hydrochar produced from red liquor at this condition was 29.87 MJ/kg, and its ash content was 1.12 wt.%. This result reflects the effect of increasing reaction temperature on the physicochemical characteristics of the hydrochar. The increase of HTC temperature significantly reduces the ash content of the hydrochar, leads to a significant increase in the carbon content of the hydrochar, and a reduction in both the oxygen and hydrogen content. These effects suggests an increase in the degree of condensation of the hydrochar products, and consequently the formation of a high energy content material. Based on TGA and FTIR analyses, hydrochars prepared at high HTC temperature showed lower adsorbed moisture, hemicellulose and cellulose contents, with enrichment in content of higher temperature volatiles, such as lignin.
Faculty
Faculty of Applied Science & Technology
School
School of Chemical and Environmental Sciences
Journal
Energies
Version
Publisher's version
Peer Reviewed/Refereed Publication
yes
Terms of Use
Terms of Use for Works posted in SOURCE.
Copyright
© 2016 by the authors; licensee MDPI, Basel, Switzerland.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Original Publication Citation
Gamgoum, R., Dutta, A., Santos, R., & Chiang, Y. (2016). Hydrothermal conversion of neutral sulfite semi-chemical red liquor into hydrochar. Energies, 9(6), 435. doi:10.3390/en9060435
SOURCE Citation
Gamgoum, Ramy; Dutta, Animesh; Santos, Rafael M.; and Chiang, Yi Wai, "Hydrothermal Conversion of Neutral Sulfite Semi-Chemical Red Liquor into Hydrochar" (2016). Faculty Publications and Scholarship. 14.
https://source.sheridancollege.ca/fast_chem_publ/14