Simultaneous Tar Reforming and Syngas Methanation for Bio-Substitute Natural Gas

Biomass steam gasification in a free-fall reactor followed by the as-produced biogenous syngas upgrading over Ni/olivine and Ni/olivine+CaO in a countercurrent moving bed reactor was performed in this study. In the newly developed moving bed configuration, the tar in the syngas was steam reformed and simultaneously the syngas was methanated. As a preliminary part of this research, the influences of tar on syngas methanation at different temperatures and H2O contents were studied as well in a fixed-bed reactor with toluene as a model tar compound. It was found that the carbon deposition behavior was greatly affected by the reaction conditions. During raw biogenous syngas upgrading over Ni/olivine in the countercurrent moving bed upgrading reactor, both CH4-rich gas production and tar elimination with good resistance toward carbon deposition were achieved. With the introduction of CO2 sorbent into the upgrading reactor further, CH4/H-2 mixture was achieved.