A solid oxide membrane electrolyzer for production of hydrogen and syn-gas from steam and hydrocarbon waste in a single step

This paper describes a novel solid oxide membrane (SOM) electrolyzer that can utilize the energy value in any hydrocarbon waste or reductant to lower the energy requirement for hydrogen production from steam. The SOM electrolyzer consists of a one-end closed oxygen-ion-conducting yttria stabilized zirconia (YSZ) tube with Ni–YSZ cathode coated on the outside and liquid metal anode inside the tube. The SOM electrolyzer is operated by feeding steam on the cathodic side and hydrocarbon reductant in the liquid metal anode. By feeding hydrocarbon waste it is possible to lower the chemical potential of oxygen in the liquid metal such that the SOM electrolyzer can spontaneously dissociate steam and generate hydrogen on the cathodic side and oxidize the hydrocarbon waste on the anodic side to produce syn-gas. The rate of these reactions can be increased by applying a small potential across the electrodes.