A novel approach to the decomposition of biogas consisting in the simultaneous production of syngas (H2 and CO mixture) and bio-nanostructured filamentous carbon (BNFC) is proposed. Catalysts with different active phases such as Ni, Co or Fe on Al2O3 are studied in the temperature range between 600 and 900 ºC. Their behaviour was analysed considering CH4 and CO2 conversions, reaction rates, catalyst stability and carbon production. Additionally, the BNFC produced were characterised by transmission electron microscopy. Depending on the active phase and the reaction temperature, different carbon types were identified: fishbone, parallel and chain-like BNFC and encapsulating carbon. Large amounts of BNFC and good catalyst stability were achieved with the Ni/Al2O3 catalyst at 600 ºC, pointing out that carbon accumulation is not directly responsible of catalyst deactivation and that the key factor is the nature of carbon formed during the reaction.

The authors acknowledge the Spanish Economy and Competitiveness Ministry and the ERDF funds for the financial support of the Project ENE2011-28318-C03-01. S. de Llobet thanks the Diputación General de Aragón for the Ph.D. grant. Authors would like to acknowledge the use of Servicio General de Apoyo a la Investigación-SAI of the University of Zaragoza.

7 pages, 2 tables, 6 figures.

Peer reviewed