Formamide hydrothermal pretreatment assisted camellia shell for upgrading to N-containing chemical and supercapacitor electrode preparation using the residue

The N-containing compounds produced from renewable biomass have attracted much attention. However, the research on N-containing monomer chemicals direct transformed from N-doping lignocellulose is rare. In this study, camellia shells were converted to tetrahydroquinoxaline and supercapacitors by hydrothermal pretreatment with formamide as the solvent. The hydrothermal conditions of time, temperature and catalyst dosages were investigated. The results indicated that the paramount content of monomer (41.79%) was obtained at 220 °C for 5 h and 0.3 content of ZnCl2 hydrothermal condition. Meanwhile, the residue of the pretreated camellia shells had the potential to be transformed into supercapacitors. The prepared electrode material exhibited a gravimetric specific capacitance of 271 F/g at 1 A/g and 99.18% of the initial capacitance retention after 2000 cycles at 10 A/g. The multi-component usage strategy improves biomass usage and economic viability for biomass refining. [Display omitted] •FA hydrothermal of camellia shell to produce N-containing monomer and supercapacitor electrode materials.•The content of N-containing compounds and tetrahydroquinoxaline reached 87.46% and 46.83%, respectively.•The supercapacitor electrode material with a specific capacitance of 271 F/g and 99.18% retention after 2000 cycles.