The subject of this study is the experimental investigation of the decomposition of calcium-enriched bio-oil (CEB), the product of the reaction of bio-oil with calcium hydroxide, at high temperatures and of the calcination of the CaCO3 material that is obtained when the decomposition is carried out in the presence Of CO2. Decomposition and calcination experiments are conducted in a thermogravimetric analysis system, and the pore structures of dried, decomposed, and calcined samples are characterized using nitrogen adsorption-desorption, mercury intrusion-extrusion, and photomicrographic examination. The calcination results for CEB-derived CaCO3 are compared with those for two naturally occurring calcitic solids of high CaCO3 content. The pore structure characterization results show that the decomposition and calcination products of CEB have very high porosities, higher than 80-90%. Because of its high porosity, the calcination product exhibits a much higher calcination rate than particles of limestones and calcites with a characteristic size similar to that of the CEB layer. This indicates that calcium-enriched bio-oil might perform as a more efficient sorbent than limestones for SO2 capture in fossil fuel combustors.