Estimation of the carbonation reaction kinetic parameters for dilute methane and carbon dioxide conditions in a calcium looping process

Experimental investigations were carried out to determine the intrinsic kinetic parameters of the carbonation reaction of limestone (CaCO 3 ) in a calcium looping (CL) process for (1) dilute carbon dioxide conditions (1 vol % CO 2 in air) and (2) dilute methane conditions (1 vol % CH 4 in air). The random pore model (RPM) was applied to estimate the gas-solid heterogeneous kinetic parameters and further used to study the effects of bed temperature, fluidizing velocity and inventory size on carbon dioxide capture and methane combustion. Experiments were conducted in a single lab-scale bubbling fluidized bed reactor on calcined limestone at a range of temperatures (450-600°C) and inventory sizes (8-16 g). The activation energy determined for the carbonation reaction in dilute CO 2 and dilute CH 4 conditions were found to be 25.7 × 10 3 kJ/kmol and 22.3 × 10 3 kJ/kmol, respectively. These values were compared with the conventional calcium looping process (12-15% CO 2 in flue gas)