Biogas as renewable raw material for syngas production by tri-reforming process over NiCeO2 catalysts: Optimal operative condition and effect of nickel content (original) (raw)

2014, Fuel Processing Technology

This study focused on the tri-reforming of simulated biogas over a Ni/ceria based catalysts (nickel content: 1.8 wt.%-31.0 wt.%) prepared by combustion synthesis to syngas production. The effects of the H 2 O/CH 4 , O 2 /CH 4 molar ratios, reaction temperature, and nickel content on the catalysts' performances were studied along with morphological investigations. The chemical-physical analysis reveals a strong interaction between support and well dispersed nickel with some part of nickel incorporated into the CeO 2 support, suggesting that the coexistence of different nickel phases, as well as the properties of the CeO 2 support, can play an important role in the catalytic activity and stability of Ni/CeO 2 catalysts. Among the samples examined, the catalyst with 7.7 wt.% Ni loading has showed the highest catalytic activity; under the reaction conditions of the feed gas molar ratios CH 4 /CO 2 /O 2 /H 2 O = 1/0.67/0.1/0.3, GHSV = 30,000 h −1 and reaction temperature of 800°C, the conversions of CH 4 and CO 2 were 98.94% and 89.22% respectively producing a syngas with a H 2 /CO = 1.34. Moreover, stable performances of the catalyst are denoted during 150 h. It was also observed that the H 2 /CO molar ratio could be flexibly adjusted by the added amounts of oxygen and steam in order to meet the requirements of downstream processes.