Patent ID: 7491309

Claim:
A hydrogen producing system comprising: a solid oxide electrolyzer cell having a cathode side and an anode side; wherein the cathode side comprises: a heat exchanger that lies down stream of an outlet of the solid oxide electrolyzer cell; the outlet being located on the cathode side of the solid oxide electrolyzer cell; a high temperature heat source that generates steam in a boiler at a temperature of about 700 to about 900° C. and a pressure of about 3 to about 20 kg/cm 2 ; and wherein the boiler is located upstream of the solid oxide electrolyzer cell; and further wherein the boiler is in fluid communication with an inlet located at the cathode side of the solid oxide electrolyzer cell; and wherein the anode side comprises: a compressor located upstream of the solid oxide electrolyzer cell wherein the compressor is operative to blow air to sweep oxygen generated at the solid oxide electrolyzer cell to a turbine; and the heat exchanger, wherein the heat exchanger lies upstream of an inlet on the anode side of the solid oxide electrolyzer cell; and wherein the heat exchanger is operative to extract heat from the steam and hydrogen emanating from the cathode side of the solid oxide electrolyzer cell; and further wherein a portion of the heat extracted is transferred to air that is provided to the anode side of the solid oxide electrolyzer cell.