Simultaneous production of hydrogen and carbon nanotubes from biogas: On the effect of Ce addition to CoMo/MgO catalyst

• Published in: International journal of hydrogen energy Vol. 46; no. 77; pp. 38175 - 38190
• Main Authors: Kludpantanapan, Thunyathon, Nantapong, Paveenuch, Rattanaamonkulchai, Raminda, Srifa, Atthapon, Koo-Amornpattana, Wanida, Chaiwat, Weerawut, Sakdaronnarong, Chularat, Charinpanitkul, Tawatchai, Assabumrungrat, Suttichai, Wongsakulphasatch, Suwimol, Sudoh, Masao, Watanabe, Ryo, Fukuhara, Choji, Ratchahat, Sakhon
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 08.11.2021
• Subjects: Biogas; Carbon nanotubes; Ce addition; CO2 methanation; CVD; Hydrogen; CVD; Carbon nanotubes; Biogas; CO2 methanation; Ce addition; Hydrogen
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.09.068

In this study, hydrogen and carbon nanotubes (CNTs) are simultaneously produced via a synergistic combined process of CO2 methanation (METH) and chemical vapor deposition (CVD) processes using biogas as a feedstock. METH process could upgrade CO2 containing biogas into CH4-rich gas which then decomposed into H2 and forming CNTs over CoMo/MgO catalyst by CVD process. The effects of Ce addition to CoMo/MgO were investigated. Comprehensive characterization confirms that all as-synthesized samples composed of well-aligned multi-walled carbon nanotubes (MWCNTs) with a narrow size distribution. The Ce addition improved CoMo dispersion on MgO, resulting in smaller and uniform CNTs. The small addition of Ce into CoMo/MgO catalyst could enhance the production CNTs yield. The higher Ce addition would, however, result in the CNTs yield decreased, attributed to a high basicity of CeO2 surface and a large coverage of CeO2 on the catalyst surface. The IG/ID increased with increased Ce addition, while the surface area monotonically decreased, attributed to a decrease in defects of nanotubes. In addition, this wisely combined process could result in a remarkable 100%CO2 elimination, while high CH4 conversion of 90% was obtained. The H2 production yield could gain more than 30 vol% with respect to H2 in the feed stream. The H2 yield and purity in the effluent gas stream were approximately 90%. •The combined process could provide a complete CO2 elimination.•The small Ce addition could enhance both yield and quality of CNTs.•The obtained CNTs has a higher graphitic carbon than the commercial CNTs.•The CH4 conversion could achieve more than 90%.•The additional H2 production could gain more than 30%.