The accumulation of sulfate in CO_2 capture solvent causes a decrease in effective components of the absorbent and corrosion of the equipments. In this paper

on the basis of measuring the sulfate accumulation rules in actual CO_2 capture process of the power plants

the electrodialysis method was used to investigate the sulfate removal performance

and the changes of salt removal rate

amine recovery rate

current efficiency and energy consumption with time at different current densities were also studied. The results show that

by using the electrodialysis method

the sulfate removal rate reached higher than 90%

which satisfied the control requirements for sulfate concentration in the CO_2 capture process. When the current density was 15 mA/cm2

the recovery rate of amine reached a maximum of 97.6%

the energy consumption for removing sulfate was 20.9 kW·h/t

and the total comprehensive cost was about 220 Yuan/t. Compared with the solvent purchasing cost(2 300 Yuan/t)

the effective regeneration of absorbent by removing sulfate using electrodialysis method has more obvious cost advantage.