Bio-carbon production by oxidation and hydrothermal carbonization of paper recycling black liquor. (10th March 2019)

• Record Type: Journal Article
• Authors: Al-Kaabi, Zainab; Pradhan, Ranjan; Thevathasan, Naresh; Gordon, Andrew; Chiang, Yi Wai; Dutta, Animesh
• Is Part Of: Journal of cleaner production. Volume 213(2019)
• Page Start: 332
• Page End: 341
• Publication Date: 2019-03-10
• Subjects: Black liquor -- Hydrogen peroxide -- Hydrothermal carbonization -- Oxidation -- Recycled paper; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2018.12.175
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Black liquor, an industrial waste, also generally called spent liquor is a promising feedstock for production of bio-carbon due to its high lignin and energy contents. Mild processing conditions and sustainable resource utilization can drive commercial utilization of this industrial waste. A novel oxidative procedure using hydrogen peroxide as a green liquid oxidant at room temperature for processing of paper recycling neutral sulphite semi-chemical spent liquor was established and evaluations were carried out for its efficiency. Standard hydrothermal carbonization was carried out for comparing bio-carbon production qualitatively and quantitatively using the same spent liquor. The oxidation procedure was performed at room temperature using 5% of H2 O2 followed by washing in diluted sulfuric acid (0.15 N) while hydrothermal carbonization was performed at 250 °C. The bio-carbon produced were similar in terms of ash percentage and ranged from 1.25 ± 0.05 to 1.48 ± 0.05% for oxidation method and from 1.11 ± 0.03 to 1.45 ± 0.04% for hydrothermal carbonization. The carbon contents for the oxidation method ranged from 60.54 to 61.50% and 66.81–67.31% for hydrothermal carbonization while higher heating values ranged from 25.32 to 26.11 MJ/kg and from 28.68 to 29.34 MJ/kg respectively. The mass yield ranged from 29.98 to 31.88% by the oxidation, while it was 15.02–16.08% by hydrothermal carbonization. Highlights: Bio-carbon is generated from byproduct of plant that uses recycled paper feedstock. Oxidation method is a promising approach to obtain pure bio-carbon from spent liquor. Hydrothermal carbonization demands energy for pure bio-carbon production. Bio-carbon from both methods differ quantitatively but are similar qualitatively. Bio-carbon can be a potential platform for environmental friendly fuel and materials.