High Efficiency Conversion of Natural Gas to Hydrogen

76193-Syngas, produced by the highly endothermic reforming of natural gas, is a feedstock for the production of hydrogen. The heat required to drive the reforming reaction is generally transferred through expensive high temperature heat exchangers or, alternatively, can be provided by partially oxidizing the methane with oxygen. However, the latter alternative is still too expensive to be used in the production of hydrogen, despite the fact that oxygen is one of the lowest cost industrial chemicals. Another problem with hydrogen separation is the production of a residual stream that contains not only carbon dioxide, which requires sequestration, but also methane, carbon monoxide, and significant quantities of hydrogen by-products, which makes the CO2 difficult to sequester. This project will develop a high-efficiency oxygen sorbent process for extracting oxygen from low-pressure air and transferring the oxygen to a nickel-catalyzed reformer. Hydrogen will be generated at process pressure (typically 20 to 40 bar) with greater than 99% purity, while avoiding the very expensive high temperature heat exchangers associated with conventional steam reforming. The process also produces a second stream of high purity CO2, ready for sequestration. Phase I will build upon previous research, which showed that strong, long-life sorbents can be made for transferring oxygen and reforming natural gas; however, in long-life tests, the sorbent lost some oxygen capacity. Therefore alternative sorbents with greater oxygen capacity will be identified and evaluated, and the cost of hydrogen production while capturing CO2 will be estimated. Commercial Applications and Other Benefits as described by the awardee: The technology should find use in the generation of electricity and/or hydrogen with little reduction in conversion efficiency while emitting far less (or no) CO2 to the atmosphere. In addition, hydrogen could be supplied for other uses such as fuel cells and fuel cell powered automobiles.