Fe(NO3)3 assisted hydrothermal carbonization of sewage sludge: Focusing on characteristics of hydrochar and aqueous phase

• Published in: Molecular catalysis 2021-09, Vol.514, p.111823, Article 111823
• Main Authors: Ma, Xue-Qin, Shan, Ya-Qi, Duan, Pei-Gao, Liao, Jun-Jie, Chen, Da-Bo, Xu, Zhi-Xiang
• Format: Article
• Language: English
• Subjects: Catalytic process; Hydrothermal carbonization; Inorganic salts; Oxidation; Sewage sludge
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2021.111823

•Enhancing hydrolysis was a key step to improving dehydration, decarboxylation, deamination and oxidation reaction for SS during HTC.•FN can notably decrease TOC, NH3-N and TN and decrease elemental content in hydrochar especially at high temperatures.•Formation Fe2O3 also could catalyze hydrochar combustion.•The role of oxidation also can be limited by the amount of FN. Fe(NO3)3 was selected as a typical nitrate (5, 10 wt.%) to analyze its effects on the hydrothermal carbonization (HTC) of sewage sludge (SS). Enhancing hydrolysis was a key step to improving dehydration and decarboxylation of SS HTC. Fe(NO3)3 could notably decrease the total organic carbon, ammonia nitrogen, and total nitrogen of the aqueous phase and elemental content of the hydrochar especially produced at high temperatures. Formation Fe2O3 could also catalyze hydrochar combustion. At different HTC temperatures, the difference between dehydration and decarboxylation could also be observed. The results would give more help to the treatment of protein-rich organic waste, particular using HTC method. [Display omitted]