Flue gas desulfurization with sodium alkali and membrane electrolysis recycling

A flue gas desulfurization process with the sodium alkali desulfurization and membrane electrolysis recycling was studied in a pilot plant. The results indicate that the current density and absorbing solution concentration can observably impact the membrane electrolysis recycling. The sulfur conversion in the middle cell is higher and the decreasing velocity of conductivity is fast with the higher current density but the current efficiency is higher with the lower current density. The increasing velocity of pH and conductivity in the cathode cell with the higher current density is greater than that with the lower current density, and the pH and conductivity in the cathode cell show an abrupt rise after 85 min during the membrane electrolysis with the higher current density of 83.33 mA · cm-2. The current efficiency and sulfur conversion in the middle cell are higher and the decreasing velocity of conductivity is fast with the lower absorbing solution concentration. However, the increasing velocity of pH and conductivity in the cathode cell with the lower absorbing solution concentration is greater than that with the higher absorbing solution concentration, and it also has an abrupt rise after some time during the membrane electrolysis.