Robin Edward Richards

Ion transport membrane technology for oxygen separation and syngas production

Abstract Ion transport membranes (ITMs) are made from ceramic materials that conduct oxygen ions at elevated temperatures. Successful application of ITM technology will allow significant improvement in the performance of several large-scale industrial processes. The ITM Oxygen process, in which ITMs are used to separate high-purity oxygen from air, has the potential for significant advantages when integrated with power generation cycles. The ITM Syngas process, by combining air separation and high-temperature syngas generation processes into a single compact ceramic membrane reactor, has the potential for substantially reducing the capital investment for gas-to-liquid (GTL) plants and for distributed hydrogen. The development efforts are major, long-term and high risk, and place severe demands on the performance and property requirements of the ITM materials. Air Products and Chemicals has joined with the U.S. Department of Energy, Ceramatec and other partners to develop, scale-up and commercialize these technologies. In addition, Air Products and Ceramatec are developing the SEOS™ Oxygen Generator, an electrically-driven, small scale, oxygen generation and removal technology using ITMs, which could have a significant impact in the global market for distributed oxygen and inert gases. This paper describes the stages of development of these three related technologies, their industrial applications, and the technical hurdles that must be overcome before successful commercialization.

Reference electrode placement and seals in electrochemical oxygen generators

We report measurements and numerical calculations of the potential distribution within a thin solid electrolyte near active (current-bearing) electrodes. These studies demonstrate two principles: (1) In a flat-plate geometry, the electrolyte is approximately equipotential beyond a distance of about three electrolyte thicknesses from the edge of the active electrodes. (2) If one of the active electrodes on one side of the electrolyte extends beyond the other, it strongly biases the potential of the electrolyte far from the active region. We show that these effects make it challenging to measure electrode overpotential accurately on thin cells. However, we also show that these effects can be useful for protecting glass-ceramic seals in an oxygen generator stack against electrochemical degradation/delamination.

Beyond state-of-the-art gas separation processes using ion-transport membranes

U.S. Department of Energys (DOE) Vision 21 program has identified oxygen and hydrogen separation membranes as enabling technology needs for futuristic, virtually non-polluting energy production plants. DOEs advanced gas separation technology RD&D activities focus on the new breed of membrane technologies to dramatically reduce the cost and energy required for gas separations. DOEs National Energy Technology Laboratory (NETL) has entered into a three-phase technology RD&D partnership with Air Products and Chemicals, Inc. (Air Products) to revolutionize the oxygen manufacturing process using dense ceramic membranes into a new century technology. DOE-NETL is supporting Eltron Research Inc. (Eltron) and ITN Energy Systems, Inc. (ITN) to develop new, low-cost, and commercially manufacturable mixed protonic-electronic conducting membranes for separating hydrogen from synthesis gas.