The economical production of hydrogen and the circulating regeneration of the sulfur dioxide adsorbent from the residuals of flue gas desulfurization were achieved in the electromembrane reactor designed in this work. The theoretical and practical considerations and a discussion of the design and operation of such a reactor are described herein. The average current efficiency of hydrogen production can reach up to 92.32% under the selected optimal operating conditions, with an average hydrogen conversion efficiency of 38.90%, which is close to the theoretical efficiency of 41.43%. The cost of hydrogen production is 8.08 $/(kg of H-2) or 2.59 $/(kg of H-2) using off-peak electricity, which are both lower than the hydrogen selling price of a small neighborhood-sized market. In addition, according to empirical calculations, regenerating the consumed adsorbent after combusting 1 ton of coal containing 1% sulfur and the flue gas desulfurization process will simultaneously produce approximately 5.50 m(3) of hydrogen.