High Oxygen/Nitrogen Selectivity Membranes

Oxygen enriched air (OEA) is a valuable tool to enhance combustion processes and improve the energy efficiency. OEA reduces the presence of parasitic nitrogen and therefore flame temperature and associated heat transfer is higher with OEA. A membrane process is the most energy efficient way to make low end OEA (25-35%). Studies show that using 35% OEA reduces fuel consumption and CO2 generation by upwards of 60%. The resulting exhaust stream is dramatically more concentrated in CO2 which enhances CO2 sequestering. Often, cryogenic oxygen is diluted with air to provide target OEA level for combustion process. The use of 99+% oxygen mixed with air is thermodynamically inefficient. Traditionally membrane systems are more superior in small to intermediate size applications. Therefore, our initial focus will be combustion sites (e.g. furnaces) where demand for oxygen beyond 21% oxygen (e.g. air) is 5-20 tons/day. The program hypothesis is to successfully develop high selectivity oxygen/nitrogen separation membranes using high flux, chemically and thermally resistant amorphous fluorinated polymer membranes as the base matrix. Based on our unique fluoropolymer synthesis technique, CMS proposes to develop a group of fluorinated polymeric membranes which have high gas permeance and selectivity. The proposed membrane can produce OEA at a much lower cost than conventional oxygen/nitrogen separation membranes. This program develops a novel membrane which produces low cost oxygen enriched air. This program will 1) reduce energy requirements for small or medium size furnaces by up to 60% and 2) provide high CO2 concentration exhaust streams for enhanced concentrating of CO2 for CO2 sequestering.

Commercial Application and Other Benefits: Oxygen is one of the top five chemicals used domestically. Small to medium size furnaces, which represent approximately 40% of the nation’s furnaces, consume less than 5 tons/day of oxygen. These 5 tons small to medium size furnaces would be ideal for low cost 25-35% OEA. Parallel CMS preliminary studies suggest if successful this program can produce 25-35% OEA with an EPO2 of $40/ton which is 50% less than conventional processes.