Limestone or calcium carbonate (CaCO3) used as a sorbent in the removal of acid gas precursors (SO2) from combustion systems suffers from poor pore structural properties which causes low reactivity and incomplete utilization. The surface area and pore size distribution of CaCO3, if tailored appropriately, can considerably enhance its reactivity for SO2. This study focuses on the optimization of pore properties of CaCO3 particles and the enhancement of SO2 reactivity and ultimate utilization. The carbonate is produced by precipitation from an aqueous suspension of calcium hydroxide by injecting CO2. The influence of operating parameters, suspension concentration, gas flow rate, and additives (surfactant) on the surface area and pore volume is investigated. The surface area of the carbonate powder can be controlled in the range of 10-70 m(2)/g by varying the operating parameters. The SO2 reactivity and the ultimate utilization of the calcium carbonate indicate a dramatic improvement and can be correlated with the surface area and pore volume characteristics of the particles.