Hydrogen Separation from a Logistic-Fuel Reformate Stream

A two step reforming process for diesel type fuels with high sulfur content is proposed. In the first step the fuel is passed through an electric arc, as a result of which the fuel decomposes into mainly hydrogen carbon monoxide, carbon dioxide and water. To prevent soot formation a certain amount of air is added to the fuel. The process is called plasma reforming, and has demonstrated high tolerance to sulfur. In the second step the fuel is passed over a dense membrane that has is conducting to oxygen ions and electrons. On the other side of the membrane steam with a small amount of hydrogen passes. Since both streams contain very small concentrations of oxygen, but the concentration on the hydrogen side can be 1000 times higher than on the reformate side, a gradient results that gives rise to a flow of oxygen ions through the membrane. The oxygen is removed from the steam and so hydrogen is left behind. Thus steam is dissociated electrochemically whereby the energy for the process is derived from electrochemical oxidation of the reformate. The membrane is coated with electrochemically active layers. On the reformate side is a ceramic material, La-Ce-SrTiO3, that has shown desirable characteristics in high sulfur environments. Since both processes take place at the same temperature and ambient pressure an integrated, compact design approach is foreseen.