Electrochemically mediated carbon capture strategies have the potential to displace thermal desorption techniques due to their ability to operate with lower energy requirements at ambient temperatures and pressure. Bipolar-membrane electrodialysis (BPM-ED) is a promising technique that uses the H + and OH -fluxes generated by electric-field-enhanced water dissociation in the BPM to drive the release of CO2 and the recovery of CO3 2-from an electrolyte containing reactive carbon species simultaneously. Herein, we developed simulations, which closely match experiments, and resolved the rates of the various kinetic and transport processes (field enhanced water or bicarbonate dissociation, homogeneous buffer reactions, salt crossover, etc.) occurring within BPMs immersed in three reactive carbon solutions relevant to carbon capture: 1 M KHCO3, 0.5 M KHCO3, and simulated seawater. Simulations reveal that an early onset in observed current density for (bi)carbonate exchanged BPMs is due to field enhanced dissociation of the bicarbonate anions as well as a reduction in H+-OH-recombination due to competitive reaction of OH-with HCO3 -to form CO3 2-indirectly.