Reactions of carbonaceous materials (activated carbon, graphite, and lignin) with carbon dioxide were carried out at 973 K using alkali metal carbonates (m.p. 891similar to1164 K) and eutectic mixtures of these compounds (m.p. 669similar to787 K) as catalysts. The reaction occurred when the carbonate catalysts were physically mixed with carbonaceous materials and the melting points of the catalysts were lower than the reaction temperature. However, the reaction did not proceed with physically mixed catalysts when the melting points of the catalysts were higher than the reaction temperature. Repeated use of the molten catalyst was also studied to investigate the possibility of continuous gasification of carbonaceous materials. After the activated carbon (or lignin) was consumed in a batch reactor, the same amount was added in the reactor containing the catalyst and the reaction started again. It was found that the eutectic molten catalyst could be reused without any loss of its catalytic activity by repeating this operation.