Synthesis of carbon nanotubes from conventional biomass-based gasification gas

• Published in: Fuel processing technology 2018-11, Vol.180, p.105-113
• Main Authors: Zhang, Baiqiang, Piao, Guilin, Zhang, Jubing, Bu, Changsheng, Xie, Hao, Wu, Bo, Kobayashi, Nobusuke
• Format: Article
• Language: English
• Subjects: Biomass; Biomass-based gasification gas; Carbon; Carbon nanotubes; CO/CH4 mixture gas decomposition; Decomposition reactions; Disproportionation; Fluidized beds; Gasification; Methane; Nanotubes; Partial pressure; Pressure ratio; Pyrolysis; Synergistic effect; Synthesis; Weight
• ISSN: 0378-3820; 1873-7188
• DOI: 10.1016/j.fuproc.2018.08.016

The gas product which synthesized from the biomass-based gasification process is a kind of rich carbon source gas. To establish the high-value applications, the synthesis process of carbon nanotubes (CNTs) from biomass-based gasification gas is established in this study. This study focused on the CNTs production process from the mixture of CO and CH4, which were primary components of biomass pyrolysis/gasification gas, in a thermogravimetric and a fluidized bed. The reaction temperature and the partial pressure of the essential role of the mixture gas were investigated. Meanwhile, in the fluidized bed, results of the decomposition of mixture gas (CO/CH4) were compared with the results by pure gas (CH4 decomposition process and CO disproportionation process). Results showed that the initial temperature for carbon weight gain increased in the mixture gas decomposition process was lower than that of the pure CH4 decomposition process in the TG reactor. In the fluidized bed, the conversions of CO and CH4 were promoted in the mixture gas decomposition process. CO and CH4 played a synergistic role with the H2 as the medium in the CO/CH4 decomposition process. With the increase of CO/CH4 partial pressure ratio, the yield and quality of CNTs increased significantly. The CNTs produced from CO/CH4 were longer and smoother than that of CH4 and CO decomposition. When the partial pressure ratio of CO/CH4 up to 2, the yield of carbon weight gain was eight times than that of same partial pressure of CH4 decomposition. Therefore, it is feasible for the decomposition of biomass-based gasification gas for the CNTs formation process. [Display omitted] •It's feasible to synthesize CNTs from biomass-based gasification gas decomposition.•XCH4, XCO, YH2 and carbon weight gain increase significantly from mixture gas than pure gas.•The mechanism of the mixture gas decomposition process is elucidated.•CH4 and CO play a synergistic role in decomposition process with H2 as medium.