Oxygen Separation Membrane For Oxy-Fuel, Coal-Fired Power Plants

A more efficient, scalable and cost-effective technology is needed to separate oxygen from air for advanced coal-fired power plants based gasification and oxy-fuel combustion. Oxygen-fired systems generate power more efficiently than conventional plants and only water and low concentration contaminants are required to be removed from the flue gas to produce carbon dioxide suitable for transport. Conventional air separation technologies are expensive and inefficient. They consume too much energy and dramatically lower plant power output. A non-cryogenic air separation technology is needed to both increase efficiency while enabling cost-effective carbon capture. Luna Innovations will develop a process that enables carbon capture in oxygen-fired power plants while increasing the plant’s power output. Despite great potential, oxy-fuel gasification and combustion are not widely used because of how much energy it takes to produce pure oxygen. This large energy penalty is unnecessary. Oxygen-fired power plants mix the flue gas exhaust with produced oxygen for gasification and combustion, however, there is enough energy in the exhaust to enrich it with oxygen without having to use traditional air separation technologies and significant amounts of energy. By enriching the flue gas recycle with oxygen, these plants can capture carbon (>90%) while increasing net power plant output compared to conventional coal-fired systems. The proposed program will focus on developing a new process that will add oxygen gas to the flue gas recycle with almost no energy input. This technology will use Luna’s advanced Thermochemical Membranes. These membranes combine the highest performance gas separation technology with operation in the most energy efficient separation conditions (200-400 °C) and beneficial integration with power plant infrastructure. In Phase I, Luna will develop a Thermochemical Membrane to enrich flue gas recycle with oxygen. Phase I will demonstrate the technical feasibility of separating oxygen with Thermochemical Membranes using a new electrolyte chemistry. The Luna team will evaluate performance of the process for integration with the flue gas recycle of new oxygen-fired plants. The Phase II program will focus on optimization and manufacturing of membranes, determining membrane performance over a wide range of conditions and temperatures, and performing a detailed systems level analysis. Luna proposes to transform power generation and enable over 90% carbon dioxide capture by generating oxygen at conditions that optimize net plant efficiency. Luna’s new process utilizes a previously unharnessed thermochemical energy gradient to transfer oxygen from air directly into a recycled flue gas. The process will enable power plants with gasification, oxy-fuel combustion, and carbon capture to operate at significantly higher net plant efficiencies and power outputs than conventional coal-fired power plants.