Direct Conversion of Syngas Produced from Steam Reforming of Toluene into Methane over a Ni/Biochar Catalyst

In the presence of a catalyst, the reforming of biomass tar to produce syngas, and its further use for chemical production, is a sustainable energy technology. However, to the best of our knowledge, the integration of tar reforming and downstream technology is still limited. In this work, an economical Ni/biochar catalyst was prepared and successfully applied for steam reforming of toluene (as a tar model compound) and syngas methanation. Under experimental conditions, the Ni/wheat straw (Ni/WS) char catalyst is active for syngas production and further for methane production in a wide temperature range. The physicochemical properties of the Ni/WS char catalyst were carefully characterized, and then the activity, stability, and deactivation of Ni/WS char in toluene reforming and methanation were elaborated. Ni/WS char possessed a smaller Ni crystallite size, and its lower activation energy resulted in higher toluene conversion (90.2%) and gas yield (261.4 mmol/gtoluene) compared with the commercial Ni/Al2O3 catalyst during toluene reforming. Furthermore, the produced syngas with an optimized H2/CO ratio of 3.01 was proved to be suitable for methane production over Ni/WS char, which therefore showed a high CO conversion (80.3%).