COUPLING REFORMING PROCESSES WITH FISCHER-TROPSCH SINTHESYS TO PRODUCE LIQUID HYDROCARBONS FROM BIOGAS

Biogas is an attractive renewable energy source, which could give an important contribution to drive the global energy system to a sustainable scenario [1]. Because of the main problems related to the direct use of biogas, a promising alternative consists in the production of syngas by reforming processes, i.e. Dry Reforming (DR), Steam Reforming (SR) and Oxy-Steam Reforming (OSR) [2]. Based on the composition of the syngas, it can be used for the synthesis of chemicals, with special reference to Gas-to-Liquids technologies [3]. In this study, the catalytic activity of Me/CeO2-based structured cordierite monoliths (Me=Rh, Pt, Ni) was preliminary probed in the SR of biogas (CH4/CO2=1.5), varying temperature (700-900°C) at fixed S/C (3) and weight space velocity (WSV=72,000 Nml gcat-1 h-1). Structured catalysts were lined by combining the Solution Combustion Synthesis with the Impregnation Technique [4] and characterized by XRD, XRF, SEM, TEM, TPR and CO-Chemisorption. Tab. 1 summarizes the results obtained at 900°C, highlighting the highest performance of the Rh-CeO2-MO system, with a methane conversion of ca. 99.8% and negligible CH4 content in the product mixture. Then, the addition of oxygen (O/C=0.5) was evaluated on the same system in the OSR of biogas at 900°C in order to have a syngas composition (CO:CO2=1:1; H2/(CO+CO2)=1.3) suitable for Fischer-Tropsch conversion (Tab. 1).